76
CRES Study Guide Page 1 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) Refrigerating Engineers & Technicians Association CRES EXAMINATION STUDY GUIDE Table of Contents Introduction to the CRES Study Guide 2 Using RETA References on Screen 2 Calculations and Refrigeration System Screens 4 Sample System Screen 5 Formulas 7 CRES References Sheet 8 Ammonia Safety Data Sheet (SDS) 10 CRES Screens 1 to 24 19 Ammonia Saturated Properties Table 41 Halocarbon Refrigerant Properties Table 49 Lighting 57 Introduction to the CRES Study Guide

RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 1 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerating Engineers & Technicians Association

CRES EXAMINATION

STUDY GUIDE

Table of Contents

Introduction to the CRES Study Guide 2

Using RETA References on Screen 2

Calculations and Refrigeration System Screens 4

Sample System Screen 5

Formulas 7

CRES References Sheet 8 Ammonia Safety Data Sheet (SDS) 10

CRES Screens 1 to 24 19

Ammonia Saturated Properties Table 41

Halocarbon Refrigerant Properties Table 49

Lighting 57

Introduction to the CRES Study Guide

Page 2: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 2 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

This CRES Examination Study Guide is designed to help you prepare to demonstrate what

you know and can do in this RETA certification test. You will improve your chances of

earning your CRES credential by treating this CRES Study Guide as you would the technical

manuals in a refrigeration facility where you work. Your chances of earning the CRES

credential improve if you are familiar with the details in the CRES Study Guide. Just as

your job requires that you know what is in operating manuals and when to refer to them to

understand or resolve a problem, the CRES test requires that you know what is in the

References document and when to use it. You will not be told when to use the references

for this test.

Using RETA References On-Screen References for each RETA test are in a PDF that appears on the screen next to test

questions. You will have the following tools for using the PDF.

• Move the red vertical line separating the two sections from side to side to assign more screen space to the References or to questions.

• Zoom in or out to make pages in the References PDF larger or smaller by clicking on

the plus (+) or minus (-) symbols at the top of the screen. This tool bar disappears after a

few seconds. The toolbar reappears when you move the mouse over the References

document.

• Scroll from page to page to find the location in the References that has the table,

formulas or other information you want to use.

Do not use the CTRL + F keys for searching in the PDF as this will cause

the testing system to think a security violation is happening and will

automatically log the test taker out and the login screen will appear.

Page 3: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 3 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

The following screens show how this will work during the test.

Screen 1 The sample question asks about controlling an ammonia fire. The

References document title page appears on the right side of the screen.

The toolbar at the top of the References document allows you to zoom in and zoom out by

clicking the plus (+) or minus (-) symbols. The toolbar disappears after a few seconds. The

toolbar reappears when you move the mouse over the References document. You cannot use the

save or print functions in the toolbar during the test. If you click on those icons, you need to

click “Cancel” in the menu that appears for either function to return to References.

Screen 2 Information to help answer the question appears in the Ammonia SDS.

Scroll to the opening page of the SDS.

Screen 3 The answer to the question appears in the first paragraph of Section 5,

Fire Fighting Measures, in the ammonia SDS. In this screen the vertical

red line has been moved

Page 4: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 4 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

to the left to increase the screen space assigned to the References document.

Calculations and Refrigeration System Screens

All calculations required in this test can be completed with a simple calculator. A scientific

calculator is NOT required to perform well on this examination. The screens that appear in

the CRES examination provide information about operating conditions in a refrigeration

system. Some screens include information about both “NORMAL” and “ABNORMAL”

operating conditions. The screens do not specify how much time has passed between these

two sets of data. Several months may have passed between the time when the “NORMAL”

and “ABNORMAL” readings were recorded.

The CRES examination requires you to demonstrate that you can use these screens to:

• Determine the condition of the refrigerant at any place in the system by knowing

how to use the information provided.

• Analyze the findings of the conditions and apply your knowledge to adjust

system components to resolve a problem and/or achieve a better running condition.

• Determine the cost of operating under the conditions indicated in the screens. In

both dollars per hour and in power demand or consumption over time.

• Use refrigerant properties tables in the CRES References and in this CRES Study

Guide to interpret information and/or solve a problem in the system’s operating

conditions. CRES references in this Study Guide will be available on screen

during the examination.

A sample screen appears on the next page. This is followed by a series of

questions you should consider as you prepare to take the CRES Examination.

Page 5: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 5 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

SAMPLE CRES SCREEN 300 HP SCREW COMPRESSOR –

NH3 NORMAL CONDITIONS

SUCTION PRESSURE 32 PSIG SCREW COMPRESSOR MOTOR

AMPS

295 AMPS

DISCHARGE PRESSURE 154 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 55 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 26°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 171°F CONDENSED LIQUID TEMP 85°F

OIL TEMPERATURE 136°F CONDENSER OUTLET PRESSURE 151 PSIG

OIL COOLER – OIL INLET

TEMP

171°F

- THERMO SIPHON OIL COOLING

- CONDENSER OUTLET NOT SUBCOOLED

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F

NOTES: POWER FACTOR IS 0.86 MOTOR TYPE IS 3 PHASE

MOTOR EFFICIENCY IS 93% CONDENSER TYPE IS EVAPORATIVE

SAMPLE CRES SCREEN 300 HP SCREW COMPRESSOR –

NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 32 PSIG SCREW COMPRESSOR MOTOR

AMPS

339 AMPS

DISCHARGE PRESSURE 184 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 55 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 26°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 192°F CONDENSED LIQUID TEMP 95°F

OIL TEMPERATURE 154°F CONDENSER OUTLET PRESSURE 181 PSIG

OIL COOLER – OIL INLET

TEMP

192°F

- THERMO SIPHON OIL COOLING

- CONDENSER OUTLET NOT SUBCOOLED

OIL COOLER –

REFRIGERANT OUTLET

TEMP

95°F

NOTES: POWER FACTOR IS 0.86 MOTOR TYPE IS 3 PHASE

MOTOR EFFICIENCY IS 93% CONDENSER TYPE IS EVAPORATIVE

Page 6: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 6 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Answer the following questions based on NORMAL Conditions in the Sample CRES Screen.

1. What is the superheat at the compressor inlet?

2. What is the temperature differential between the oil cooler oil inlet and the oil outlet?

3. What is the temperature differential between the oil cooler coolant outlet and the

oil outlet?

4. What is the superheat at the compressor outlet?

5. What is the theoretical discharge temperature of the compressor under these conditions?

6. What is the pressure drop from the compressor discharge to the condenser outlet?

7. What is the excess pressure due to non-condensables in the system?

8. What is the condition of the refrigerant leaving the oil cooler?

9. How much horsepower is being developed by the compressor motor under the

normal conditions?

10. What is the instantaneous Kw demand developed by the compressor motor under

normal conditions?

11. If power is $0.17 per kwh, how much does it cost to run the motor under normal

conditions for one hour? For one day (24 hours)? For one week? For a 5000 run-hour

year?

Answer the following questions based on ABNORMAL Conditions in the Sample

CRES Screen.

12. What is the superheat at the compressor inlet?

13. What is the temperature differential between the oil cooler oil inlet and the oil outlet?

14. What is the temperature differential between the oil cooler coolant outlet and the

oil outlet?

15. What is the oil cooling coolant?

16. What is the superheat at the compressor outlet?

17. What is the theoretical discharge temperature of the compressor under these conditions?

18. What is the pressure drop from the compressor discharge to the condenser outlet?

19. What is the excess pressure due to non-condensables in the “abnormal” system?

20. What is the condition of the refrigerant leaving the oil cooler?

21. How much horsepower is being developed by the compressor motor?

22. What is the instantaneous Kw demand developed by the compressor motor?

23. If power is $0.17 per kwh, how much does it cost to run the motor under normal

conditions for one hour? For one day (24 hours)? For one week? For a 5000 run-time

year?

24. What is the excess cost per hour for running poorly? For 24 hours? For one week?

For a 5000 run-hour year?

25. What would happen to the condenser sump temperature if the fans were not running

if you assume the wet bulb temperature is the same as under NORMAL conditions?

26. What would happen to the condenser sump water temperature if the pump was

not running if you assume the wet bulb temperature is the same as under

NORMAL conditions?

27. What might happen to the condenser sump water temperature if the coils were sealed

up significantly?

28. What might be going on that causes the higher condensing conditions?

Answer sheet on RETA website; Certification tab; CRES tab

Page 7: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 7 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Area of a rectangle:

Area of a circle:

A = Radius • Radius • 3.1416

A = side1• side2

Volume of a room V = side1• side2 • side3

Volume of a cylinder V = Length • radius • radius • 3.1416

One Horsepower (HP or BHP) = 2545 BTU / HR

To find kiloWatts of power (3 phase )

kW = Amps • Volts • PowerFactor •1.73

1000

To find Brake Horsepower used by a driven device (3 phase motor)

BHP = Amps • Volts • PowerFactor • Efficiency

746

• 1.73

To find Power Cost in Dollars per Hour:

Cost($) = ($ price per kiloWatt hour • kiloWatt hours metered ) Hours operated

To find Brake Horsepower (used by a driven device) per TR (Ton of Refrigeration)

BHP per Ton = BHP

TR

To find kiloWatts per Ton of Refrigeration (TR)

kiloWatts per Ton = kW

TR

Heat Transfer Equations Where: M= Mass or weight of object Cp =

Specific Heat of object

(T1-T2) = Difference in temperature before and after process

hL = Latent Heat quantity in a pound of the object

Sensible Heat Transfer: Qsensible = M • Cp • (T1− T 2)

Latent Heat Transfer: Qlatent = M • hL

Page 8: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 8 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Compression Ratio Equation:

Ratio = Absolute Discharge Pressure / Absolute Suction Pressure

Vacuum Conversion: Use Saturation Tables

Reprinted with permission from Cascade Energy Engineering, Inc.

Page 9: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 9 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Reprinted with permission from Cascade Energy Engineering, Inc.

Page 10: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 10 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

GHS Safety Data Sheet

Product Identifier: Anhydrous Ammonia

Synonyms/Common Names: Ammonia; NH3

Product Use & Restrictions: Refer to label

CAS Number: 7664-41-7 HBCC MSDS No. CA10000

Hill Brothers Chemical Company

1675 No. Main Street, Orange, California 92867

Telephone No: 714-998-8800 | Outside CA: 800-821-7234 Emergency: Chemtrec: 800-424-9300

Classifications of the Product

Flammable Gases – Category 2

Gases Under Pressure – Compressed

Gas Acute Toxicity: Inhalation –

Category 3 Skin Corrosion/Irritation –

Category 1B

Serious Eye Damage/Eye Irritation – Category

1 Aquatic Toxicity (Chronic) – Category 1

Labels | Signal Word: DANGER

Pictograms:

Hazard Statements

Flammable Gas

Contains gas under pressure; may explode if heated Toxic if inhaled Causes severe skin burns and eye damage

Very toxic to aquatic life with long lasting effects

Revision Issued: 5/20/2014 Supersedes: 2/22/2012

(Sections changed: No Changes) First Issued: 12/01/85

Section 1 – Identification of the Product and Manufacturer

Section 2 – Hazard Identifications

Page 11: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 11 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Precautionary Statements

Wear protective gloves: >8 hours (breakthrough time): Use chemical-resistant,

impervious gloves. Wear eye or face protection (Recommended: Chemical Splash

Proof Goggles, Face shield). Wear protective clothing (Recommended: Chemical-

resistant apron).

Keep away from heat, sparks, open flames and hot surfaces. – No

Smoking. Use only outdoors or in a well-ventilated area.

Avoid release to the environment.

Avoid breathing gas.

Wash hands thoroughly after handling.

Collect spillage.

Remove victim to fresh air and keep at rest in a position comfortable for

breathing. Immediately call a POISON CENTER or physician.

IF SWALLOWED: Immediately call a POISON CENTER of physician. Rinse mouth.

Do NOT induce vomiting.

IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin

with water or shower. Wash contaminated clothing before reuse. Immediately

call a POISON CENTER or physician.

IF IN EYES: Rinse cautiously with water for several minutes. Remove contact

lenses, if present and easy to do so. Continue rinsing. Immediately call a

POISON CENTER or physician.

Leaking gas fire: Do not extinguish, unless can be stopped

safely. Eliminate all ignition sources if safe to do so.

Store locked up.

Protect from

sunlight. Store in a well-ventilated place.

Dispose of contents and container in accordance with all local, regional, national and

international regulations.

Contact eye lenses should never be worn while handling anhydrous ammonia.

Chemical Name: Ammonia Synonyms/Common Names: Ammonia; NH3 CAS Number: 7664-41-7

Anhydrous Ammonia (NH3) 99.8 – 99.999% wt

Water 0.2% -.001% wt.

Section 3 – Composition/Information on Ingredients

Page 12: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 12 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Ingestion: If this gas is swallowed in liquid form, keep victim warm and OBTAIN

IMMEDIATE MEDICAL ATTENTION. If signs of respiratory obstruction develop,

immediately transport to medical facility. Do not induce vomiting. Never give fluids or

induce vomiting if patient is unconscious or having convulsions.

Inhalation: Remove victim to fresh air. Give oxygen if breathing is difficult.

If breathing has stopped, start artificial respiration. OBTAIN IMMEDIATE

MEDICAL ATTENTION.

Skin: Apply water immediately to exposed areas of skin and continue for at least

30 minutes. Remove contaminated clothing, shoes, and constrictive clothing while

continuing to apply water, being careful not to tear the skin. If skin surface is

damaged, apply a clean dressing. If skin surface is not damaged, cleanse the

affected area(s) thoroughly with mild soap and water. Do not apply salves or

ointments to affected areas. OBTAIN IMMEDIATE MEDICAL ATTENTION.

Eyes: Remove victim to fresh air. Immediately flush with plenty of water for at least

30 minutes with the eyelids held apart. OBTAIN IMMEDIATE MEDICAL ATTENTION.

Medical Conditions Generally Aggravated by Exposure: Ammonia is a

respiratory irritant. Persons with impaired pulmonary function may be at an

increased risk from exposure. Also pre-existing skin disorders may be aggravated by

exposure.

Summary of Acute Health Hazards

Ingestion: This material is a gas under normal atmospheric conditions and ingestion

is unlikely. Ingestion of liquid ammonia may result in severe irritation or ulceration of

the mouth, throat and digestive tract which may be displayed by nausea, vomiting,

diarrhea and, in severe cases, collapse, shock and death.

Inhalation: Irritation to the mucous membranes of the nose, throat and lungs is

noticeable at 100 ppm. Concentrations above 400 ppm will cause throat irritation

and may destroy mucous surfaces upon prolonged contact. High concentrations can

cause pulmonary edema. Breathing air containing concentrations greater than

5,000 ppm may cause sudden death from spasm or inflammation of the larynx.

Skin: Liquid Ammonia produces severe skin burns on contact. Ammonia gas may

cause skin irritation, especially if skin is moist. The liquid can cause skin damage

resulting from combined freezing and corrosive action on the skin. Atmospheric

concentrations above 30,000 ppm will burn and blister skin after a few seconds of

exposure.

Eyes: Exposure to high gas concentrations may cause temporary blindness and

severe eye damage. Direct contact of the eyes with liquid ammonia will produce

serious eye burns.

Section 4 - First Aid Measures

Page 13: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 13 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Extinguishing Media: Use Water Spray or Water Fog, Carbon Dioxide, Polar or

Alcohol Foam, Dry Chemical. Halon may decompose into toxic materials. Carbon

dioxide can displace oxygen. Use caution when applying halon or carbon dioxide in

confined spaces.

Unusual Fire and Explosion Hazards: Gas may ignite at vapor concentrations

between 16% and 25% in air. However, ammonia-air mixtures are difficult to

ignite and burn with little vigor. In the absence of oxygen enrichment, the risk of

initiating an accidental fire or explosion is low. Do not allow ammonia vapors to

accumulate in confined areas where ignition may occur. Intense heating

particularly in contact with hot metallic surfaces may cause decomposition of

ammonia generating hydrogen, a flammable gas.

Special Protective Equipment for Firefighters: Stop flow of gas. Use water fog to

keep fire-exposed containers cool and to protect personnel effecting the shut-off.

Wear self-contained breathing apparatus (SCBA) and encapsulating chemical

protective clothing. Approach fire upwind and evacuate area downwind. Emergency

responders in the danger area should wear bunker gear and self-contained breathing

apparatus for fires beyond the incipient stage (29CFR 1910.156). In addition, wear

other appropriate protective equipment as conditions warrant (See Section VIII).

Isolate damage area, keep unauthorized personnel out. Stop spill/release if it can

be done with minimal risk. If this cannot be done, allow fire to burn. Move

undamaged containers from danger area if it can be done with minimal risk. Stay

away from ends of container. Water spray may be useful in minimizing or

dispersing vapors.

Cool equipment exposed to fire with water, if it can be done with minimal risk.

Additional Description Requirement: Inhalation

Hazard NFPA Rating: Health - 3; Flammability - 1;

Instability - 0 0=Insignificant 1=Slight 2=Moderate

3=High 4=Extreme

According to the (UFC) Uniform Fire Code Standard 79-3 (2000), the degree of

Hazard is 3-3-0 in a confined space.

Section 5 - Fire Fighting Measures

Page 14: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 14 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Personal Precautions: Note that although ammonia gas is lighter than air,

sudden release may generate an aerosol of liquefied ammonia which may cling to

the ground for long distances. May ignite in the presence of open flames and

sparks. Narrow lower to upper combustion range (16-25%) makes ignition difficult.

Keep all sources of ignition away from spill/release. Do not apply water onto

leaking tank. Stop the flow of gas or liquid. Use water to protect personnel

effecting the shut-off. Approach from upwind. Evacuate the area immediately.

Eliminate all open flames in vicinity of indoor spills or released vapor. Water fog

can be used to cleanse atmosphere of ammonia vapor. Downwind areas can be

protected by water fog nozzles positioned downwind.

Protective Equipment: Wear full protective clothing and self-contained breathing

apparatus.

Emergency Procedures: Do not enter a visible cloud of ammonia. Isolate and

evacuate the leak or spill area immediately for at least 150 feet in all directions. For

larger spills, isolate at least 300 feet in all directions and then evacuate area

downwind at least 0.4 miles in width and at least 0.8 miles in length. Keep area

isolated until gas has dispersed.

Methods of Containment and Clean-Up: Dike liquid spills to contain liquid.

Safe Handling: Contents are under pressure. The use of explosion-proof

equipment is recommended and may be required (see appropriate fire codes). Do

not enter confined spaces such as tanks or pits without following proper entry

procedures such as ASTM D-4276. Protect against physical damage.

Storage: Outside shaded area or detached storage is preferred. Inside storage

should be in a cool, dry, well ventilated, noncombustible location, away from

all possible sources of ignition.

Work/Hygienic Practices: Avoid contact with skin and avoid breathing vapors. Do

not eat, drink, or smoke in work area. Wash hands before eating, drinking, or using

restroom. Do NOT place food, coffee or other drinks in the area where dusting or

splashing of solutions is possible.

Ventilation: Local exhaust is essential. Spark-proof fans desirable with mechanical

ventilation. Ducts should be located at ceiling level and lead upwards to the outside.

Eyewash fountain and safety shower should be available in work area.

Section 6 - Accidental Release Measures

Section 7 - Handling and Storage

Page 15: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 15 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Exposure Limits: Anhydrous Ammonia: CAS Number 7664-41-7, Exposure Limits

(TWAs) in Air: ACGIH TLV: 25 ppm, 18 mg/m3; OSHA PEL: 50 ppm, 35 mg/m3;

CAL- OSHA: 25 ppm, 18 mg/m3 Oregon-OSHA: 25 ppm, 18 mg/m3; STEL: 35 ppm,

27 mg/m3

Engineering Controls: See Section 7: Ventilation

Personal Protection

Personal Protection Equipment (PPE): Unless ventilation is adequate to

keep concentration below permissible exposure limit (PEL), wear NIOSH

approved ammonia chemical cartridge or canister full facepiece chin-style

respirators with an air-purification factor (APF=50). In emergency or planned

entry into unknown concentrations, use self-contained breathing apparatus

(SCBA) or any supplied-air full facepiece chin-style respirators.

Protective Clothing: Rubber or synthetic chemical gloves and boots should be

worn as well as cotton clothing and underwear. Rubber or synthetic chemical coats

or aprons should be available, an encapsulating chemical protective clothing

garment is desirable for heavy exposures. The use of long sleeved clothing closed at

the neck is advised. Change if clothing becomes contaminated.

Eye Protection: Chemical splash goggles should be worn when handling

Anhydrous Ammonia to protect from liquids or mists. A face shield can be worn

over chemical splash goggles as additional protection. Do not wear contact lenses

when handling Anhydrous Ammonia. A full-face air-purifying respirator

(APR) or supplied-air respirator (SAR) should be worn to protect from chemical

vapors.

Appearance: Compressed Liquid Gas,

clear, colorless

Odor: Sharp, penetrating

Odor Threshold: 5 ppm pH: 11.6 for 1% NH3 solution

Freezing Point: -107.9F; -78C Initial Boiling Point/Range: -28F; -33.43C

Flash Point: N/A Evaporation Rate: N/A

Flammability: 16 – 25% in air Upper/Lower Explosive Limit: 25% by

Volume/16% by Volume

Vapor Pressure (mmHg): 110 PSIG

at 68F ( 20C)

Vapor Density (Air=1): 0.0549 lb/ft3 at -

28F at 1 atm

Relative Density: 42.57 lbs./cu.ft @

-28F and 1 atm

Solubility in Water: 33.10%

Partition Coefficient: N/A Autoignition Temperature: 650° C;

1204°F

Decomposition Temperature: N/A Viscosity: N/A

% Volatiles: 100%

Molecular Weight: 17.032

Specific Gravity (Water=1): 0.6189 of liquid at -28F and 1 atm

Critical Temperature: 271.4F (133.0C)

Section 8 - Exposure Controls/Personal Protection

Section 9 - Physical and Chemical Properties

Page 16: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 16 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Reactivity: Reacts violently and explosively with oxidizing gases such as

chlorine, bromine, and other halogens. Reacts explosively with

hypochlorites such as bleach. Reacts vigorously with acids. Highly

reactive with reducing agents. Hazardous polymerization will not occur.

Chemical Stability: Stable

Possibility of Hazardous Reactions or Polymerization: Avoid contact with

oxidizing gases, chlorine, bromine, mineral hypochlorite, iodine, halogens, calcium,

and strong acids. Avoid contact with copper, silver, zinc, and alloys of same. Mercury, silver oxide can form explosive compounds.

Conditions to Avoid: Avoid all possible sources of ignition. Heat will increase

pressure in the storage tank.

Hazardous Decomposition Products: Combustion will generate oxides

of nitrogen. Intense heating of the gas, particularly in contact with hot

metallic surfaces, may cause decomposition of ammonia to hydrogen and

nitrogen.

Routes of Exposure: Inhalation is expected to be the primary route of

occupational exposure to chlorine. Chlorine liquid is corrosive to the eyes, mucous

membranes and skin.

Symptoms related to physical, chemical, and toxicological characteristics:

Can cause burning of the eyes, conjunctivitis, skin irritation, swelling of the

eyelids and lips, dry red mouth and tongue, burning in the throat, and coughing,

and in more severe cases of exposure, difficulty in breathing, signs and symptoms

of lung congestion, and, ultimately, death from respiratory failure due to

pulmonary edema may occur. Acute and Chronic effects: Can cause irritation

and burns of the skin and mucous membranes, and headache, salivation, nausea,

and vomiting. Difficult or labored breathing and cough with bloody mucous

discharge. Can cause bronchitis, laryngitis, hemoptysis, and pulmonary edema or

pneumonitis. Death may result.

Can cause ulceration of the conjunctiva and cornea, and corneal and

lenticular opacities.

Damage to the eyes may be permanent.

Numerical Measures of

Toxicity

Oral 350 Rat ATSDR

96 Mo EPA 1989

Inhalation 19,770 F EPA 1989

14,140 M EPA 1989

17,401 Ra ATSDR

Carcinogenicity Lists: NTP: No IARC Monograph: No OSHA Regulated: Yes

Section 10 - Stability and Reactivity

Section 11 - Toxicological Information

Page 17: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 17 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Ecotoxicity: Even at extremely low concentrations aquatic life will be harmed by

liquid ammonia. Persistence and degradability: N/A

Bioaccumulative Potential: N/A

Mobility In Soil: When anhydrous ammonia is applied in the soil, ammonia reacts

with organic matter, and it dissolves in water. Anhydrous Ammonia it reacts with

water to form ammonium. The initial reactions with water, organic matter and clays

limit the mobility of ammonia.

Method of Disposal: Because of the toxicity of ammonia to aquatic organisms,

NEVER dispose of or allow any ammonia or ammonia contaminated water to flow

into any surface water bodies. Surface water bodies include drainage ditches,

storm water and sanitary sewers, wetlands, ponds, lakes and streams. Diking will

contain the liquid and allow it to stabilize. Keep unprotected personnel away from

area until it is free of ammonia. Do not apply water directly to ammonia liquid as

this will cause boiling and splattering. Soil contaminated with ammonia or aqua

ammonia may need to be excavated and properly disposed of according to local

and state regulations. Consult Federal, State, or Local Authorities for additional proper disposal procedures.

UN#: UN1005

UN/DOT Proper Shipping Name: Anhydrous Ammonia

Transport Hazard Class: 2.2 (Domestic), 2.3, (8)

International Packing Group: N/A

Marine Pollutant: Yes

Transport in Bulk: N/A

Special Precautions: N/A

CERCLA Reportable Quantity: 100 Pounds (45.4 Kilograms) (19.43

Gals) EPCRA Section 302 - Ammonia 7664-41-7 – TPQ - 500 Pounds

EPCRA Section 304 RQ – 100 Pounds

EPCRA Section 312 - Ammonia 7664-41-

7

EPCRA Section 313 - Ammonia 7664-41-

7 CAA 112 (r) TQ – 10,000 Pounds

Ammonia - TSCA Chemical Substance Inventory

IDLH Value*: 300 ppm * The Immediately Dangerous to

Life and Health Value

Maximum use level for Anhydrous Ammonia under NSF/ANSI Standard 60 Maximum Use 5 mg/L

Section 13 - Disposal Considerations

Section 14 - Transport Information

Section 15 - Regulatory Information

Section 12 - Ecological Information

Page 18: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Study Guide Page 18 of 76

©2019 Refrigerating Engineers & Technicians Association (RETA)

Chemical Family/Type: Hydride, (Alkaline Gas), Inorganic Base

Section changed since last revision: MSDS to First Issue SDS Conversion

IMPORTANT! Read this SDS before use or disposal of this product. Pass along the information to

employees and any other persons who could be exposed to the product to be sure that they are

aware of the information before use or other exposure. This SDS has been prepared according to the

OSHA Hazard Communication Standard [29 CFR 1910.1200]. The SDS information is based on

sources believed to be reliable. However, since data, safety standards, and government regulations

are subject to change and the conditions of handling and use, or misuse are beyond our control, Hill

Brothers Chemical Company makes no warranty, either expressed or implied, with respect to the

completeness or continuing accuracy of the information contained herein and disclaims all liability for

reliance thereon. Also, additional information may be necessary or helpful for specific conditions and

circumstances of use. It is the user's responsibility to determine the suitability of this product and to

evaluate risks prior to use, and then to exercise appropriate precautions for protection of employees

and others.

Section 16 - Other Information

Page 19: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 19 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 1 RECIPROCATING COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 213°F CONDENSER LIQUID TEMP 85°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 151 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

CRES SCREEN 2 RECIPROCATING COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 213°F CONDENSER LIQUID TEMP 85°F

MOTOR POWR FACTOR 0.82 CONDENSER OUTLET PRESSURE 151 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

RECIPROCATING COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 161 AMPS

DISCHARGE PRESSURE 184 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 234°F CONDENSER LIQUID TEMP 85°F

MOTOR POWR FACTOR 0.82 CONDENSER OUTLET PRESSURE 181 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

Page 20: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 20 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 3

RECIPROCATING COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 213°F CONDENSER LIQUID TEMP 85°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 151 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

RECIPROCATING COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 171 AMPS

DISCHARGE PRESSURE 213 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

95°F

DISCHARGE TEMP 251°F CONDENSER LIQUID TEMP 105°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 210 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

Page 21: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 21 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 4

RECIPROCATING COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 213°F CONDENSER LIQUID TEMP 85°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 151

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

RECIPROCATING COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 60°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 269°F CONDENSER LIQUID TEMP 85°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 151

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

CRES SCREEN 5

RECIPROCATING COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG COMPRESSOR MOTOR AMPS 145 AMPS

DISCHARGE PRESSURE 154 PSIG COMPRESSOR MOTOR VOLTAGE 480 VAC

OIL PRESSURE 45 PSID COMPRESSOR LOADING 100%

SUCTION TEMP 60°F CONDENSER WATER SUMP

TEMP

72°F

DISCHARGE TEMP 269°F CONDENSER LIQUID TEMP 85°F

MOTOR POWER FACTOR 0.82 CONDENSER OUTLET PRESSURE 151 PSIG

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE COMPRESSOR WATER COOLED

CONDENSER OUTLET NOT SUBCOOLED

Page 22: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 22 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 6

500 HP SCREW COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG SCREW COMPRESSOR MOTOR

AMPS

464 AMPS

DISCHARGE PRESSURE 154 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 45 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 166°F CONDENSED LIQUID TEMP 85°F

OIL TEMPERATURE 136°F CONDENSER OUTLET PRESSURE 151 PSIG

OIL COOLER – OIL INLET

TEMP

156°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

86°F

MOTOR POWER FACTOR 0.82

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE THERMO SIPHON OIL COOLING

CONDENSER OUTLET NOT SUBCOOLED

Page 23: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 23 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 7 500 HP SCREW COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG SCREW COMPRESSOR MOTOR

AMPS

464 AMPS

DISCHARGE PRESSURE 154 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 45 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 166°F CONDENSED LIQUID TEMP 85°F

OIL TEMPERATURE 136°F CONDENSER OUTLET PRESSURE 151 PSIG

OIL COOLER – OIL INLET

TEMP

156°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

86°F

MOTOR POWER FACTOR 0.82

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE THERMO SIPHON OIL COOLING

CONDENSER OUTLET NOT SUBCOOLED

500 HP SCREW COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG SCREW COMPRESSOR MOTOR

AMPS

503 AMPS

DISCHARGE PRESSURE 167 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 45 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 171°F CONDENSED LIQUID TEMP 85°F

OIL TEMPERATURE 145°F CONDENSER OUTLET PRESSURE 165 PSIG

OIL COOLER – OIL INLET

TEMP

165°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F

MOTOR POWER FACTOR 0.82

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE THERMO SIPHON OIL COOLING

CONDENSER OUTLET NOT SUBCOOLED

Page 24: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 24 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 8

500 HP SCREW COMPRESSOR – NH3 NORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG SCREW COMPRESSOR MOTOR

AMPS

464 AMPS

DISCHARGE PRESSURE 154 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 45 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 22°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 166°F CONDENSED LIQUID TEMP 85°F

OIL TEMPERATURE 136°F CONDENSER OUTLET PRESSURE 151 PSIG

OIL COOLER – OIL INLET

TEMP

156°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

86°F

MOTOR POWER FACTOR 0.82

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE THERMO SIPHON OIL COOLING

CONDENSER OUTLET NOT SUBCOOLED

500 HP SCREW COMPRESSOR – NH3 ABNORMAL CONDITIONS

SUCTION PRESSURE 33 PSIG SCREW COMPRESSOR MOTOR

AMPS

503 AMPS

DISCHARGE PRESSURE 187 PSIG SCREW COMPRESSOR MOTOR

VOLTAGE

480 VAC

OIL PRESSURE 45 PSID SCREW COMPRESSOR SLIDE

VALVE POSITION

100%

SUCTION TEMP 20°F CONDENSER WATER SUMP

TEMP

75°F

DISCHARGE TEMP 174°F CONDENSED LIQUID TEMP 96°F

OIL TEMPERATURE 145°F CONDENSER OUTLET PRESSURE 184 PSIG

OIL COOLER – OIL INLET

TEMP

165°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

96°F

MOTOR POWER FACTOR 0.82

NOTES: MOTOR TYPE IS 3 PHASE MOTOR EFFICIENCY IS 92%

CONDENSER TYPE IS EVAPORATIVE THERMO SIPHON OIL COOLING

CONDENSER OUTLET NOT SUBCOOLED

Page 25: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 25 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 9

TWO -STAGE PACKAGE – NH3 NORMAL CONDITIONS

LOW STAGE COMPRESSOR HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 154 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 24°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 156°F CONDENSED LIQUID TEMP 85°F CONDENSER OUTLET PRESSURE 151 PSIG

OIL TEMPERATURE 125°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 145°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR MOTOR

AMPS

49 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR SLIDE

VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

TWO -STAGE PACKAGE – NH3 ABNORMAL CONDITIONS

LOW STAGE COMPRESSOR HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 197 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 24°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 164°F CONDENSED LIQUID TEMP 85°F CONDENSER OUTLET PRESSURE 194 PSIG

OIL TEMPERATURE 125°F OIL TEMPERATURE 132°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 152°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR MOTOR

AMPS

59 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR SLIDE

VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

Page 26: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 26 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 10

TWO -STAGE PACKAGE – NH3 NORMAL CONDITIONS

LOW STAGE COMPRESSOR READINGS

HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 154 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 24°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 156°F

OIL TEMPERATURE 125°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 145°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR

MOTOR AMPS

49 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR

SLIDE VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

TWO -STAGE PACKAGE – NH3 ABNORMAL CONDITIONS

LOW STAGE COMPRESSOR

READINGS

HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 154 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 74°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 165°F

OIL TEMPERATURE 125°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 145°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR

MOTOR AMPS

52 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR

SLIDE VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

Page 27: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 27 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 11

TWO -STAGE PACKAGE – NH3 NORMAL CONDITIONS

LOW STAGE COMPRESSOR READINGS HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 154 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 24°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 156°F

OIL TEMPERATURE 86°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 145°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR

MOTOR AMPS

49 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR

SLIDE VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

TWO- STAGE PACKAGE – NH3 ABNORMAL CONDITIONS

LOW STAGE COMPRESSOR READINGS HIGH STAGE COMPRESSOR READINGS

SUCTION PRESSURE 37 PSIG SUCTION PRESSURE 35 PSIG

DISCHARGE PRESSURE 37 PSIG DISCHARGE PRESSURE 114 PSIG

OIL PRESSURE 0 PSID OIL PRESSURE 45 PSID

SUCTION TEMP 68°F SUCTION TEMP 32°F

DISCHARGE TEMP 68°F DISCHARGE TEMP 150°F

OIL TEMPERATURE 86°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

85°F OIL COOLER – OIL INLET

TEMP

135°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

0 AMPS HIGH STAGE COMPRESSOR

MOTOR AMPS

49 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

0% HIGH STAGE COMPRESSOR

SLIDE VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

Page 28: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 28 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 12

TWO- STAGE PACKAGE – NH3 ABNORMAL CONDITIONS

LOW STAGE COMPRESSOR READINGS HIGH STAGE COMPRESSOR READINGS SUCTION PRESSURE 9” HG SUCTION PRESSURE 31 PSIG

DISCHARGE PRESSURE 31 PSIG DISCHARGE PRESSURE 154 PSIG

OIL PRESSURE 45 PSID OIL PRESSURE 45 PSID

SUCTION TEMP -38°F SUCTION TEMP 74°F

DISCHARGE TEMP 135°F DISCHARGE TEMP 165°F

OIL TEMPERATURE 125°F OIL TEMPERATURE 125°F

OIL COOLER – OIL INLET

TEMP

135°F OIL COOLER – OIL INLET TEMP 145°F

OIL COOLER –

REFRIGERANT OUTLET

TEMP

85°F OIL COOLER – REFRIGERANT

OUTLET TEMP

85°F

BOOSTER COMPRESSOR

MOTOR AMPS

48 AMPS HIGH STAGE COMPRESSOR

MOTOR AMPS

52 AMPS

BOOSTER COMPRESSOR

SLIDE VALVE POSITION

100% HIGH STAGE COMPRESSOR SLIDE

VALVE POSITION

100%

MOTOR POWER FACTOR 0.82 MOTOR POWER FACTOR 0.82

NOTES: THERMO SIPHON OIL COOLING MOTOR EFFICIENCY IS 92%

MOTOR TYPE IS 3 PHASE MOTOR VOLTAGE(S) IS 480 VAC

Page 29: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 29 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 13

MEDIUM TEMPERATURE ROOM – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

33 PSIG AIR LEAVING TEMPERATURE 31°F

COIL SUCTION HEADER

TEMPERATURE

20°F ROOM AIR TEMPERATURE 33°F

LIQUID LEVEL

FEED STATUS

29%

SATISFIED

MODE: REFRIGERATING

EVAPORATOR FAN

MOTOR AMPS

7.2 AMPS

COMPRESSOR INLET

PRESSURE

30 PSIG PARAMETERS:

ROOM TEMP: 33°F

ROOM HIGH TEMP: 38°F

ROOM LOW TEMP: 32°F

LIQUID LEVEL CALL: 25%

LIQUID LEVEL SATISFIED: 31%

LIQUID HIGH LEVEL: 40%

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

23°F

COMPRESSOR

DISCHARGE TEMP

212°F

NOTES:

- UNIT IS A FLOODED EVAPORATOR WITH A SOLENOID ACTIVATED BACK PRESSURE

REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A HAND EXPANSION

VALVE. - ENGINE ROOM USES MULTIPLE RECIPROCATING COMPRESSORS.

Page 30: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 30 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 14

MEDIUM TEMPERATURE ROOM – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

33 PSIG AIR LEAVING TEMPERATURE 31°F

COIL SUCTION HEADER

TEMPERATURE

20°F ROOM AIR TEMPERATURE 33°F

LIQUID LEVEL

FEED STATUS

29% SATISFIED

MODE: REFRIGERATING

EVAPORATOR FAN

MOTOR AMPS

7.2 AMPS

COMPRESSOR INLET

PRESSURE

30 PSIG PARAMETERS: ROOM TEMP: 33°F

ROOM HIGH TEMP: 38°F

ROOM LOW TEMP: 32°F

LIQUID LEVEL CALL: 25%

LIQUID LEVEL SATISFIED: 31%

LIQUID HIGH LEVEL: 40%

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

23°F

COMPRESSOR

DISCHARGE TEMP

212°F

MEDIUM TEMPERATURE ROOM – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

33 PSIG AIR LEAVING TEMPERATURE 41°F

COIL SUCTION HEADER

TEMPERATURE

40°F ROOM AIR TEMPERATURE 41°F

LIQUID LEVEL

FEED STATUS

0% CALLING

MODE: REFRIGERATING

EVAPORATOR FAN

MOTOR AMPS

7.2 AMPS

COMPRESSOR INLET

PRESSURE

25 PSIG PARAMETERS:

ROOM TEMP: 33°F

ROOM HIGH TEMP: 38°F

ROOM LOW TEMP: 32°F

LIQUID LEVEL CALL: 25%

LIQUID LEVEL SATISFIED: 31%

LIQUID HIGH LEVEL: 40%

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

38°F

COMPRESSOR

DISCHARGE TEMP

260°F

NOTES:

- UNIT IS A FLOODED EVAPORATOR WITH A SOLENOID ACTIVATED BACK PRESSURE

REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A HAND EXPANSION

VALVE.

- ENGINE ROOM USES MULTIPLE RECIPROCATING COMPRESSORS.

Page 31: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 31 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 15

MEDIUM TEMPERATURE ROOM – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

33 PSIG COMPRESSOR DISCHARGE TEMP 212°F

COIL SUCTION HEADER

TEMPERATURE

20°F AIR LEAVING TEMPERATURE 31°F

LIQUID LEVEL

FEED STATUS

29% SATISFIED

ROOM AIR TEMPERATURE 33°F

EVAPORATOR FAN MOTOR

AMPS

7.2 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

30 PSIG PARAMETERS:

ROOM TEMP: 33°F LIQUID HIGH LEVEL: 40%

ROOM HIGH TEMP: 38°F DEFROST PUMP DOWN: 20 MIN

ROOM LOW TEMP: 32°F DEFROST HOT GAS REG: 90 PSIG

LIQUID LEVEL CALL: 25% FAN DELAY: 2 MIN

LIQUID LEVEL SATISFIED: 31%

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET TEMP 23°F

MEDIUM TEMPERATURE ROOM – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

90 PSIG COMPRESSOR DISCHARGE TEMP 224°F

COIL SUCTION HEADER

TEMPERATURE

60°F AIR LEAVING TEMPERATURE 34°F

LIQUID LEVEL

FEED STATUS

95% HIGH

ROOM AIR TEMPERATURE 33°F

EVAPORATOR FAN MOTOR

AMPS

0.0 AMPS MODE: DEFROST – HG “ON”

COMPRESSOR INLET

PRESSURE

30 PSIG PARAMETERS:

ROOM TEMP: 33°F LIQUID HIGH LEVEL: 40%

ROOM HIGH TEMP: 38°F DEFROST PUMP DOWN: 20 MIN

ROOM LOW TEMP: 32°F DEFROST HOT GAS REG: 90 PSIG

LIQUID LEVEL CALL: 25% FAN DELAY: 2 MIN

LIQUID LEVEL SATISFIED: 31%

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET TEMP 65°F

NOTES:

- UNIT IS A FLOODED EVAPORATOR WITH A SOLENOID ACTIVATED BACK PRESSURE REGULATOR

FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED.

- EVAPORATOR IS ONE OF SEVERAL IN THE SYSTEM.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A HAND EXPANSION VALVE. - ENGINE ROOM USES MULTIPLE RECIPROCATING COMPRESSORS.

Page 32: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 32 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 16 LOW TEMPERATURE ROOM – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

8” HG AIR LEAVING TEMPERATURE -28°F

COIL SUCTION HEADER

TEMPERATURE

-39°F ROOM AIR TEMPERATURE -25°F

RECIRCULATOR LIQUID LEVEL

FEED STATUS

29% SATISFIED

MODE: REFRIGERATING

EVAPORATOR FAN MOTOR

AMPS

13.6 AMPS

COMPRESSOR INLET PRESSURE 12” HG PARAMETERS:

ROOM TEMP: -25°F

ROOM HIGH TEMP: -20°F ROOM LOW TEMP: -30°F

LIQUID LEVEL CALL: 25%

LIQUID LEVEL SATISFIED: 31%

LIQUID HIGH LEVEL: 40%

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET TEMP -40°F

COMPRESSOR DISCHARGE TEMP 153°F

NOTES:

- ROOM IS A SMALL BOX WITH A SINGLE UNIT.

- UNIT IS A PUMPED LIQUID EVAPORATOR USING AXIAL PROPELLER FANS AND A GAS

POWERED SUCTION OUTLET CONTROL VALVE.

- HOT GAS DEFROST METHOD USED.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A HAND EXPANSION

VALVE.

- ENGINE ROOM USES MULTIPLE SCREW COMPRESSORS ARRANGED AS A TWO STAGE

SYSTEM

Page 33: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 33 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 17 LOW TEMPERATURE ROOM – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

8” HG AIR LEAVING TEMPERATURE -28°F

COIL SUCTION HEADER

TEMPERATURE

-39°F ROOM AIR TEMPERATURE -25°F

RECIRCULATOR LIQUID

LEVEL FEED STATUS

29% SATISFIED

MODE: REFRIGERATING

EVAPORATOR FAN

MOTOR AMPS

13.6 AMPS

COMPRESSOR INLET

PRESSURE

12” HG PARAMETERS:

ROOM TEMP:

ROOM HIGH TEMP:

ROOM LOW TEMP:

LIQUID LEVEL CALL:

LIQUID LEVEL SATISFIED:

LIQUID HIGH LEVEL:

DEFROST PUMP DOWN: DEFROST HOT GAS REG:

FAN DELAY:

-25°F

-20°F

-30°F

25%

31%

40%

20 MIN

90 PSIG

2 MIN

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

-40°F

COMPRESSOR DISCHARGE

TEMP

153°F

LOW TEMPERATURE ROOM – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

10” HG AIR LEAVING TEMPERATURE -18°F

COIL SUCTION HEADER

TEMPERATURE

-42°F ROOM AIR TEMPERATURE -18°F

RECIRCULATOR LIQUID

LEVEL FEED STATUS

26% SATISFIED

MODE: REFRIGERATING

EVAPORATOR FAN

MOTOR AMPS

14.9 AMPS

COMPRESSOR INLET

PRESSURE

12” HG PARAMETERS:

ROOM TEMP:

ROOM HIGH TEMP:

ROOM LOW TEMP:

LIQUID LEVEL CALL:

LIQUID LEVEL SATISFIED:

LIQUID HIGH LEVEL:

DEFROST PUMP DOWN:

DEFROST HOT GAS REG:

FAN DELAY:

-25°F

-20°F

-30°F

25% 31%

40%

20 MIN

90 PSIG

2 MIN

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

-46°F

COMPRESSOR DISCHARGE

TEMP

151°F

NOTES:

- ROOM IS A SMALL BOX WITH A SINGLE UNIT.

- UNIT IS A PUMPED LIQUID EVAPORATOR USING AXIAL PROPELLER FANS AND A GAS

POWERED SUCTION OUTLET CONTROL VALVE.

- HOT GAS DEFROST METHOD USED.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A HAND EXPANSION

VALVE.

- ENGINE ROOM USES MULTIPLE SCREW COMPRESSORS ARRANGED AS A TWO STAGE

SYSTEM

Page 34: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 34 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Page 35: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 35 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 18

LOW SIDE VESSELS PANEL – NH3 NORMAL CONDITIONS

LOW STAGE

RECIRCULATOR READINGS

FLASH INTERCOOLER READINGS

SUCTION PRESSURE 9” HG HIGH STAGE SUCTION PRESSURE 31 PSIG

SUCTION TEMPERATURE -38°F INTERCOOLER SUCTION

INLET TEMPERATURE

156°F

VESSEL LIQUID LEVEL

FEED STATUS

31% SATISFIED

INTERCOOLER SUCTION

OUTLET TEMPERATURE

24°F

TOTAL PUMP AMPERAGE 15.7 AMPS

INTERCOOLER LIQUID LEVEL

LIQUID FEED STATUS

25% SATISFIED

PUMP DISCHARGE

HEADER PRESSURE

20 PSIG PARAMETERS: LOW STAGE RECIRCULATOR LIQUID CALL: 25%

LOW STAGE RECIRCULATOR LIQUID SATISFIED: 30%

LOW STAGE RECIRCULATOR LIQUID HIGH LEVEL: 40%

LOW STAGE RECIRCULATOR LIQUID LOW LEVEL: 15%

INTERCOOLER LIQUID LEVEL CALL: 23%

INTERCOOLER LIQUID LEVEL SATISFIED: 27%

INTERCOOLER LIQUID HIGH LEVEL: 34%

INTERCOOLER LIQUID LOW LEVEL: 18%

INTERCOOLER SUCTION OUTLET HIGH TEMP: 40°F

PUMP MOTOR AMPS: LOW 8.2 HIGH: 17.2 MINIMUM PUMP DISCHARGE PRESSURE DIFFERENTIAL: 22 PSID

Page 36: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 36 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 19

LOW SIDE VESSELS PANEL – NH3 NORMAL CONDITIONS

LOW STAGE FLASH INTERCOOLER READINGS

RECIRCULATOR READINGS

SUCTION PRESSURE 9” HG HIGH STAGE SUCTION PRESSURE 31 PSIG

SUCTION TEMPERATURE -38°F INTERCOOLER SUCTION 156°F INLET TEMPERATURE

VESSEL LIQUID LEVEL 31% INTERCOOLER SUCTION 24°F

FEED STATUS SATISFIED OUTLET TEMPERATURE

TOTAL PUMP AMPERAGE 15.7 INTERCOOLER LIQUID LEVEL 25% AMPS LIQUID FEED STATUS SATISFIED

PUMP HEADER 20 PSIG PARAMETERS:

PRESSURE LOW STAGE RECIRCULATOR LIQUID CALL: 25% LOW STAGE RECIRCULATOR LIQUID SATISFIED: 30%

LOW STAGE RECIRCULATOR LIQUID HIGH LEVEL: 40%

LOW STAGE RECIRCULATOR LIQUID LOW LEVEL: 15%

INTERCOOLER LIQUID LEVEL CALL: 23%

INTERCOOLER LIQUID LEVEL SATISFIED: 27%

INTERCOOLER LIQUID HIGH LEVEL: 34%

INTERCOOLER LIQUID LOW LEVEL: 18%

INTERCOOLER SUCTION OUTLET HIGH TEMP: 40°F

PUMP MOTOR AMPS: LOW 8.2 HIGH: 17.2

MINIMUM PUMP DISCHARGE PRESSURE DIFFERENTIAL: 22 PSID

LOW SIDE VESSELS PANEL – NH3 ABNORMAL CONDITIONS

LOW STAGE

RECIRCULATOR READINGS

FLASH INTERCOOLER READINGS

SUCTION PRESSURE 11” HG HIGH STAGE SUCTION PRESSURE 31 PSIG

SUCTION TEMPERATURE -42°F INTERCOOLER SUCTION

INLET TEMPERATURE

156°F

VESSEL LIQUID LEVEL

FEED STATUS

4% FILLING

INTERCOOLER SUCTION

OUTLET TEMPERATURE

45°F

TOTAL PUMP AMPERAGE 0 AMPS INTERCOOLER LIQUID LEVEL

LIQUID FEED STATUS

5% FILLING

PUMP HEADER

PRESSURE

9” HG PARAMETERS: LOW STAGE RECIRCULATOR LIQUID CALL: 25%

LOW STAGE RECIRCULATOR LIQUID SATISFIED: 30%

LOW STAGE RECIRCULATOR LIQUID HIGH LEVEL: 40%

LOW STAGE RECIRCULATOR LIQUID LOW LEVEL: 15%

INTERCOOLER LIQUID LEVEL CALL: 23%

INTERCOOLER LIQUID LEVEL SATISFIED: 27%

INTERCOOLER LIQUID HIGH LEVEL: 34% INTERCOOLER LIQUID LOW LEVEL: 18%

INTERCOOLER SUCTION OUTLET HIGH TEMP: 40°F

PUMP MOTOR AMPS: LOW 8.2 HIGH: 17.2 MINIMUM PUMP DISCHARGE PRESSURE DIFFERENTIAL: 22 PSID

Page 37: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 37 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 20

LOW SIDE VESSELS PANEL – NH3 NORMAL CONDITIONS

LOW STAGE FLASH INTERCOOLER READINGS

RECIRCULATOR READINGS

SUCTION PRESSURE 9” HG HIGH STAGE SUCTION PRESSURE 31 PSIG

SUCTION TEMPERATURE -38°F INTERCOOLER SUCTION 156°F INLET TEMPERATURE

VESSEL LIQUID LEVEL 31% INTERCOOLER SUCTION 24°F

FEED STATUS SATISFIED OUTLET TEMPERATURE

TOTAL PUMP AMPERAGE 15.7 INTERCOOLER LIQUID LEVEL 25% AMPS LIQUID FEED STATUS SATISFIED

PUMP HEADER 20 PSIG PARAMETERS:

PRESSURE LOW STAGE RECIRCULATOR LIQUID CALL: 25% LOW STAGE RECIRCULATOR LIQUID SATISFIED: 30%

LOW STAGE RECIRCULATOR LIQUID HIGH LEVEL: 40%

LOW STAGE RECIRCULATOR LIQUID LOW LEVEL: 15%

INTERCOOLER LIQUID LEVEL CALL: 23%

INTERCOOLER LIQUID LEVEL SATISFIED: 27%

INTERCOOLER LIQUID HIGH LEVEL: 34%

INTERCOOLER LIQUID LOW LEVEL: 18%

INTERCOOLER SUCTION OUTLET HIGH TEMP: 40°F

PUMP MOTOR AMPS: LOW 8.2 HIGH: 17.2

MINIMUM PUMP DISCHARGE PRESSURE DIFFERENTIAL: 22 PSID

LOW SIDE VESSELS PANEL – NH3 ABNORMAL CONDITIONS

LOW STAGE

RECIRCULATOR READINGS

FLASH INTERCOOLER READINGS

SUCTION PRESSURE 1” HG HIGH STAGE SUCTION PRESSURE 38 PSIG

SUCTION TEMPERATURE -38°F INTERCOOLER SUCTION

INLET TEMPERATURE

75°F

VESSEL LIQUID LEVEL

FEED STATUS

28% SATISFIED

INTERCOOLER SUCTION

OUTLET TEMPERATURE

30°F

TOTAL PUMP AMPERAGE 0.0 AMPS INTERCOOLER LIQUID LEVEL

LIQUID FEED STATUS

45% HIGH

PUMP HEADER

PRESSURE

0.0 PSIG PARAMETERS: LOW STAGE RECIRCULATOR LIQUID CALL: 25%

LOW STAGE RECIRCULATOR LIQUID SATISFIED: 30%

LOW STAGE RECIRCULATOR LIQUID HIGH LEVEL: 40%

LOW STAGE RECIRCULATOR LIQUID LOW LEVEL: 15%

INTERCOOLER LIQUID LEVEL CALL: 23%

INTERCOOLER LIQUID LEVEL SATISFIED: 27%

INTERCOOLER LIQUID HIGH LEVEL: 34%

INTERCOOLER LIQUID LOW LEVEL: 18%

INTERCOOLER SUCTION OUTLET HIGH TEMP: 40°F

PUMP MOTOR AMPS: LOW 8.2 HIGH: 17.2 MINIMUM PUMP DISCHARGE PRESSURE DIFFERENTIAL: 22 PSID

Page 38: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 38 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 21

DIRECT EXPANSION DOCK UNITS – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 33°F

COIL SUCTION HEADER

TEMPERATURE

30°F ROOM AIR TEMPERATURE 35°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

28 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

34°F

COMPRESSOR

DISCHARGE TEMP

235°F

NOTES:

- UNIT IS A DIRECT EXPANSION EVAPORATOR WITH A SOLENOID ACTIVATED BACK

PRESSURE REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED WHICH IS SUPPLIED FROM A COMMON

CONDENSER.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A THERMOSTATIC

EXPANSION VALVE. - ENGINE ROOM USES A SINGLE RECIPROCATING COMPRESSOR FOR THIS LOAD.

Page 39: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 39 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 22

DIRECT EXPANSION DOCK UNITS – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 33°F

COIL SUCTION HEADER

TEMPERATURE

30°F ROOM AIR TEMPERATURE 35°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

28 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

34°F

COMPRESSOR

DISCHARGE TEMP

235°F

DIRECT EXPANSION DOCK UNITS – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 42°F

COIL SUCTION HEADER

TEMPERATURE

42°F ROOM AIR TEMPERATURE 42°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

22 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

44°F

COMPRESSOR

DISCHARGE TEMP

280°F

NOTES:

- UNIT IS A DIRECT EXPANSION EVAPORATOR WITH A SOLENOID ACTIVATED BACK

PRESSURE REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED WHICH IS SUPPLIED FROM A COMMON

CONDENSER.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A THERMOSTATIC

EXPANSION VALVE. - ENGINE ROOM USES A SINGLE RECIPROCATING COMPRESSOR FOR THIS LOAD.

Page 40: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 40 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 23

DIRECT EXPANSION DOCK UNITS – NH3 NORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 33°F

COIL SUCTION HEADER

TEMPERATURE

30°F ROOM AIR TEMPERATURE 35°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

28 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

34°F

COMPRESSOR DISCHARGE

TEMP

235°F

DIRECT EXPANSION DOCK UNITS – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 30°F

COIL SUCTION HEADER

TEMPERATURE

17°F ROOM AIR TEMPERATURE 33°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

29 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR DISCHARGE

PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

17°F

COMPRESSOR DISCHARGE

TEMP

140°F

NOTES:

- UNIT IS A DIRECT EXPANSION EVAPORATOR WITH A SOLENOID ACTIVATED BACK

PRESSURE REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED WHICH IS SUPPLIED FROM A COMMON CONDENSER.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A THERMOSTATIC

EXPANSION VALVE. - ENGINE ROOM USES A SINGLE RECIPROCATING COMPRESSOR FOR THIS LOAD.

Page 41: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 41 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

CRES SCREEN 24

DIRECT EXPANSION DOCK UNITS – NH3 ABNORMAL CONDITIONS

COIL SUCTION HEADER

PRESSURE

30 PSIG AIR LEAVING TEMPERATURE 30°F

COIL SUCTION HEADER

TEMPERATURE

17°F ROOM AIR TEMPERATURE 33°F

EVAPORATOR FAN

MOTOR AMPS

8.4 AMPS MODE: REFRIGERATING

COMPRESSOR INLET

PRESSURE

29 PSIG PARAMETERS:

ROOM TEMP: 34°F

ROOM HIGH TEMP: 40°F

ROOM LOW TEMP: 32°F

DEFROST PUMP DOWN: 20 MIN

DEFROST HOT GAS REG: 90 PSIG

FAN DELAY: 2 MIN

COMPRESSOR

DISCHARGE PRESSURE

154 PSIG

COMPRESSOR INLET

TEMP

17°F

COMPRESSOR

DISCHARGE TEMP

140°F

NOTES:

- UNIT IS A DIRECT EXPANSION EVAPORATOR WITH A SOLENOID ACTIVATED BACK

PRESSURE REGULATOR FOR EVAPORATOR PRESSURE CONTROL.

- HOT GAS DEFROST METHOD USED WHICH IS SUPPLIED FROM A COMMON

CONDENSER.

- LIQUID FEED IS AN ELECTRIC SOLENOID VALVE IN SERIES WITH A THERMOSTATIC

EXPANSION VALVE. - ENGINE ROOM USES A SINGLE RECIPROCATING COMPRESSOR FOR THIS LOAD.

Page 42: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 42 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

SOURCE: INTERNATIONAL INSTITUTE OF AMMONIA REFRIGERATION PROPERTIES BOOK

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

-65 20.4“ hg 4.69 0.0227 52.5619 44.15 0.0190

-64 20.0“ hg 4.84 0.0227 50.8815 44.11 0.0197

-63 19.7“ hg 5.02 0.0227 49.3229 44.07 0.0203

-62 19.4“ hg 5.18 0.0227 47.7644 44.03 0.0209

-61 19.0“ hg 5.37 0.0227 46.3175 43.99 0.0216

-60 18.6“ hg 5.53 0.0228 44.8709 43.95 0.0223

-59 18.2“ hg 5.72 0.0228 43.5023 43.90 0.0230

-58 17.8“ hg 5.91 0.0228 42.1830 43.86 0.0237

-57 17.4“ hg 6.11 0.0228 40.9108 43.82 0.0244

-56 17.0“ hg 6.31 0.0228 39.6840 43.78 0.0252

-55 16.6“ hg 6.52 0.0229 38.5006 43.74 0.0260

-54 16.2“ hg 6.73 0.0229 37.3589 43.69 0.0268

-53 15.7“ hg 6.95 0.0229 36.2572 43.65 0.0276

-52 15.3“ hg 7.18 0.0229 35.1939 43.61 0.0284

-51 14.8“ hg 7.41 0.0230 34.1675 43.57 0.0293

-50 14.3“ hg 7.64 0.0230 33.1765 43.53 0.0301

-49 13.8“ hg 7.89 0.0230 32.2196 43.48 0.0310

-48 13.3“ hg 8.14 0.0230 31.2953 43.44 0.0320

-47 12.8“ hg 8.39 0.0230 30.4025 43.40 0.0329

-46 12.2“ hg 8.66 0.0230 29.5398 43.46 0.0339

-45 11.7“ hg 8.92 0.0231 28.7062 43.32 0.0348

-44 11.1“ hg 9.20 0.0231 27.9004 43.27 0.0358

-43 10.6“ hg 9.48 0.0231 27.1216 43.23 0.0369

-42 10.0“ hg 9.77 0.0232 26.3685 43.19 0.0379

-41 9.3“ hg 10.07 0.0232 25.6402 43.15 0.0390

-40 8.7“ hg 10.38 0.0232 24.9359 43.10 0.0401

-39 8.1“ hg 10.69 0.0232 24.2545 43.06 0.0412

Page 43: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 43 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

-38 7.4“ hg 11.01 0.0232 23.5953 43.02 0.0424

-37 6.8“ hg 11.34 0.0233 22.9574 42.97 0.0436

-36 6.1“ hg 11.67 0.0233 22.3400 42.93 0.0448

-35 5.4“ hg 12.01 0.0233 21.7423 42.89 0.0460

-34 4.7“ hg 12.37 0.0233 21.1637 42.85 0.0473

-33 3.9“ hg 12.73 0.0234 20.6035 42.80 0.0485

-32 3.2“ hg 13.10 0.0234 20.0609 42.76 0.0498

-31 2.4“ hg 13.47 0.0234 19.5353 42.72 0.0512

-30 1.6“ hg 13.86 0.0234 19.0262 42.67 0.0526

-29 .8“ hg 14.25 0.0235 18.5328 42.63 0.0540

-28 0 psig 14.66 0.0235 18.0548 42.59 0.0554

-27 0.37 15.07 0.0235 17.5914 42.55 0.0568

-26 0.79 15.49 0.0235 17.1422 42.50 0.0583

-25 1.23 15.93 0.0236 16.7068 42.46 0.0599

-24 1.67 16.37 0.0236 16.2845 42.42 0.0614

-23 2.12 16.82 0.0236 15.8750 42.37 0.0630

-22 2.58 17.28 0.0236 15.4778 42.33 0.0646

-21 3.05 17.75 0.0236 15.0925 42.29 0.0663

-20 3.54 18.24 0.0237 14.7187 42.24 0.0679

-19 4.03 18.73 0.0237 14.3559 42.20 0.0697

-18 4.53 19.23 0.0237 14.0038 42.16 0.0714

-17 5.05 19.75 0.0237 13.6621 42.11 0.0732

-16 5.57 20.27 0.0238 13.3303 42.07 0.0750

Page 44: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 44 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

-15 6.11 20.81 0.0238 13.0082 42.02 0.0769

-14 6.66 21.36 0.0238 12.6954 41.98 0.0788

-13 7.22 21.92 0.0238 12.3917 41.94 0.0807

-12 7.79 22.49 0.0239 12.0966 41.89 0.0827

-11 8.37 23.07 0.0239 11.8100 41.85 0.0847

-10 8.96 23.66 0.0239 11.5315 41.81 0.0867

-9 9.57 24.27 0.0239 11.2608 41.76 0.0888

-8 10.19 24.89 0.0240 10.9978 41.72 0.0909

-7 10.82 25.52 0.0240 10.7422 41.67 0.0931

-6 11.47 26.17 0.0240 10.4937 41.63 0.0953

-5 12.13 26.83 0.0240 10.2521 41.59 0.0975

-4 12.80 27.50 0.0241 10.0172 41.54 0.0998

-3 13.48 28.18 0.0241 9.7887 41.50 0.1022

-2 14.18 28.88 0.0241 9.5665 41.45 0.1045

-1 14.89 29.59 0.0241 9.3503 41.41 0.1069

0 15.62 30.32 0.0242 9.1401 41.36 0.1094

1 16.36 31.06 0.0242 8.9355 41.32 0.1119

2 17.11 31.81 0.0242 8.7364 41.27 0.1145

3 17.88 32.58 0.0243 8.5426 41.23 0.1171

4 18.66 33.36 0.0243 8.3540 41.19 0.1197

5 19.46 34.16 0.0243 8.1704 41.14 0.1224

6 20.28 34.98 0.0243 7.9917 41.10 0.1251

7 21.10 35.80 0.0244 7.8177 41.05 0.1279

8 21.95 36.65 0.0244 7.6482 41.01 0.1307

9 22.81 37.51 0.0244 7.4831 40.96 0.1336

10 23.68 38.38 0.0244 7.3224 40.92 0.1366

Page 45: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 45 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

11 24.58 39.28 0.0245 7.1657 40.87 0.1396

12 25.48 40.18 0.0245 7.0132 40.82 0.1426

13 26.41 41.11 0.0245 6.8645 40.78 0.1457

14 27.35 42.05 0.0246 6.7196 40.73 0.1488

15 28.31 43.01 0.0246 6.5784 40.69 0.1520

16 29.28 43.98 0.0246 6.4408 40.64 0.1553

17 30.28 44.98 0.0246 6.3066 40.60 0.1586

18 31.29 45.99 0.0247 6.1758 40.55 0.1619

19 32.32 47.02 0.0247 6.0483 40.51 0.1653

20 33.36 48.06 0.0247 5.9240 40.46 0.1688

21 34.43 49.13 0.0247 5.8027 40.41 0.1723

22 35.51 50.21 0.0248 5.6844 40.37 0.1759

23 36.61 51.31 0.0248 5.5690 40.32 0.1796

24 37.73 52.43 0.0248 5.4564 40.27 0.1833

25 38.87 53.57 0.0249 5.3466 40.23 0.1870

26 40.03 54.73 0.0249 5.2395 40.18 0.1909

27 41.21 55.91 0.0249 5.1349 40.14 0.1947

28 42.41 57.11 0.0249 5.0328 40.09 0.1987

29 43.62 58.32 0.0250 4.9332 40.04 0.2027

30 44.86 59.56 0.0250 4.8360 40.00 0.2068

31 46.12 60.82 0.0250 4.7410 39.95 0.2109

32 47.40 62.10 0.0251 4.6483 39.90 0.2151

33 48.70 63.40 0.0251 4.5678 39.85 0.2189

34 50.02 64.72 0.0251 4.4695 39.81 0.2237

35 51.37 66.07 0.0252 4.3831 39.76 0.2281

Page 46: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 46 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

36 52.73 67.43 0.0252 4.2988 39.71 0.2326

37 54.12 68.82 0.0252 4.2165 39.67 0.2372

38 55.53 70.23 0.0252 4.1360 39.62 0.2418

39 56.96 71.66 0.0253 4.0574 39.57 0.2465

40 58.41 73.11 0.0253 3.9806 39.52 0.2512

41 59.89 74.59 0.0253 3.9055 39.47 0.2560

42 61.39 76.09 0.0254 3.8321 39.43 0.2610

43 62.91 77.61 0.0254 3.7604 39.38 0.2659

44 64.46 79.16 0.0254 3.6903 39.33 0.2710

45 67.03 81.73 0.0255 3.6218 39.28 0.2761

46 67.63 82.33 0.0255 3.5548 39.23 0.2813

47 69.25 83.95 0.0255 3.4893 39.18 0.2866

48 70.89 85.59 0.0255 3.4253 39.14 0.2919

49 72.56 87.26 0.0256 3.3626 39.09 0.2974

50 74.25 88.95 0.0256 3.3014 39.04 0.3029

51 75.97 90.67 0.0256 3.2415 38.99 0.3085

52 77.71 92.41 0.0257 3.1828 38.94 0.3142

53 79.48 94.18 0.0257 3.1255 38.89 0.3199

54 81.28 95.98 0.0257 3.0694 38.84 0.3258

55 83.10 97.80 0.0258 3.0145 38.79 0.3317

56 84.95 99.65 0.0258 2.9608 38.74 0.3377

57 86.83 101.53 0.0258 2.9082 38.69 0.3439

58 88.73 103.43 0.0259 2.8568 38.64 0.3500

59 90.66 105.36 0.0259 2.8064 38.59 0.3563

60 92.62 107.32 0.0259 2.7571 38.54 0.3627

Page 47: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 47 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

61 94.60 109.30 0.0260 2.7089 38.49 0.3692

62 96.62 111.32 0.0260 2.6616 38.44 0.3757

63 98.66 113.36 0.0260 2.6154 38.39 0.3824

64 100.73 115.43 0.0261 2.5701 38.34 0.3891

65 102.83 117.53 0.0261 2.5257 38.29 0.3959

66 104.96 119.66 0.0262 2.4823 38.24 0.4029

67 107.12 121.82 0.0262 2.4397 38.19 0.4099

68 109.31 124.01 0.0262 2.3981 38.14 0.4170

69 111.53 126.23 0.0263 2.3572 38.09 0.4242

70 113.78 128.48 0.0263 2.3173 38.04 0.4315

71 116.06 130.76 0.0263 2.2781 37.99 0.4390

72 118.37 133.07 0.0264 2.2397 37.93 0.4465

73 120.71 135.41 0.0264 2.2021 37.88 0.4541

74 123.08 137.78 0.0264 2.1652 37.83 0.4619

75 125.48 140.18 0.0265 2.1291 37.78 0.4697

76 127.92 142.62 0.0265 2.0936 37.73 0.4776

77 130.39 145.09 0.0265 2.0589 37.67 0.4857

78 132.89 147.59 0.0266 2.0249 37.62 0.4939

79 135.42 150.12 0.0266 1.9915 37.57 0.5021

80 137.99 152.69 0.0267 1.9588 37.52 0.5105

81 140.59 155.29 0.0267 1.9268 37.46 0.5190

82 143.22 157.92 0.0267 1.8953 37.41 0.5276

83 145.89 160.59 0.0268 1.8645 37.36 0.5363

84 148.59 163.29 0.0268 1.8342 37.31 0.5452

85 151.33 166.03 0.0268 1.8046 37.25 0.5541

Page 48: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 48 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

86 154.10 168.80 0.0269 1.7755 37.20 0.5632

87 156.90 171.60 0.0269 1.7470 37.14 0.5724

88 159.75 174.45 0.0270 1.7190 37.09 0.5817

89 162.62 177.32 0.0270 1.6915 37.04 0.5912

90 165.54 180.24 0.0270 1.6646 36.98 0.6007

91 168.48 183.18 0.0271 1.6381 36.93 0.6105

92 171.47 186.17 0.0271 1.6122 36.87 0.6203

93 174.49 189.19 0.0272 1.5867 36.82 0.6302

94 177.55 192.25 0.0272 1.5617 36.77 0.6403

95 180.65 195.35 0.0272 1.5372 36.71 0.6505

96 183.78 198.48 0.0273 1.5131 36.66 0.6609

97 186.95 201.65 0.0273 1.4895 36.60 0.6714

98 190.16 204.86 0.0274 1.4663 36.55 0.6820

99 193.41 208.11 0.0274 1.4436 36.49 0.6927

100 196.70 211.40 0.0274 1.4212 36.43 0.7036

101 200.02 214.72 0.0275 1.3993 36.38 0.7146

102 203.39 218.09 0.0275 1.3777 36.32 0.7258

103 206.80 221.50 0.0276 1.3565 36.27 0.7372

104 210.24 224.94 0.0276 1.3358 36.21 0.7486

105 213.73 228.43 0.0277 1.3153 36.15 0.7603

106 217.25 231.95 0.0277 1.2953 36.10 0.7720

107 220.82 235.52 0.0277 1.2756 36.04 0.7839

108 224.43 239.13 0.0278 1.2563 35.98 0.7960

109 228.08 242.78 0.0278 1.2373 35.93 0.8082

110 231.77 246.47 0.0279 1.2186 35.87 0.8206

Page 49: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 49 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant R717 (Ammonia)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

ft3/lb.

Specific

Volume

Vapor

ft3/lb.

Density

Liquid

lbs./ ft3

Density

Vapor

lbs./ ft3

111 235.50 250.20 0.0279 1.2003 35.81 0.8331

112 239.28 253.98 0.0280 1.1822 35.75 0.8459

113 243.10 257.80 0.0280 1.1645 35.70 0.8587

114 246.96 261.66 0.0281 1.1471 35.64 0.8718

115 250.87 265.57 0.0281 1.1300 35.58 0.8850

116 255.40 269.52 0.0282 1.1132 35.52 0.8983

117 259.40 273.51 0.0282 1.0967 35.46 0.9118

118 263.50 277.55 0.0282 1.0805 35.41 0.9255

119 267.60 281.63 0.0283 1.0645 35.35 0.9394

120 271.70 285.76 0.0283 1.0488 35.29 0.9535

121 275.90 289.93 0.0284 1.0334 35.23 0.9677

122 280.10 294.15 0.0284 1.0183 35.17 0.9820

123 284.40 298.41 0.0285 1.0033 35.11 0.9967

124 288.70 302.72 0.0285 0.9887 35.05 1.0114

125 293.10 307.08 0.0286 0.9743 34.99 1.0264

Page 50: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 50 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

SOURCE: INTERNATIONAL INSTITUTE OF AMMONIA REFRIGERATION PROPERTIES BOOK TABLE 1

Refrigerant HCFC-22 Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

-65 14.4“ hg 7.6 0.011053 6.29 90.47 0.15910

-64 13.9“ hg 7.9 0.011065 6.11 90.38 0.16355

-63 13.5“ hg 8.1 0.011077 5.95 90.28 0.16809

-62 13.0“ hg 8.3 0.011089 5.79 90.18 0.17274

-61 12.5“ hg 8.6 0.011101 5.63 90.08 0.17749

-60 12.0“ hg 8.8 0.011111 5.48 90.00 0.18233

-59 11.4“ hg 9.1 0.011125 5.34 89.89 0.18729

-58 10.9“ hg 9.4 0.011137 5.20 89.79 0.19235

-57 10.4“ hg 9.6 0.011149 5.06 89.69 0.19752

-56 9.8“ hg 9.9 0.011161 5.06 89.60 0.19752

-55 9.2“ hg 10.2 0.011174 4.80 89.49 0.20818

-54 8.6“ hg 10.5 0.011186 4.68 89.40 0.21368

-53 8.0“ hg 10.8 0.011198 4.56 89.30 0.21929

-52 7.4“ hg 11.1 0.011211 4.44 89.20 0.22502

-51 6.8“ hg 11.4 0.011223 4.33 89.10 0.23087

-50 6.2“ hg 11.7 0.011235 4.22 89.01 0.23683

-49 5.5“ hg 12.0 0.011248 4.12 88.90 0.24292

-48 4.8“ hg 12.3 0.011261 4.01 88.80 0.24913

-47 4.1“ hg 12.7 0.011273 3.91 88.71 0.25546

-46 3.4“ hg 13.0 0.011286 3.82 88.61 0.26192

-45 2.7“ hg 13.4 0.011298 3.72 88.51 0.26851

-46 2.0“ hg 13.7 0.011311 3.63 88.41 0.27523

-44 1.3“ hg 14.1 0.011324 3.55 88.31 0.28207

-43 0.5“ hg 14.5 0.011337 3.46 88.21 0.28905

-42 0.1 psig 14.8 0.011350 3.38 88.11 0.29617

-41 0.5 15.2 0.011363 3.30 88.00 0.30342

-39 0.9 15.6 0.111376 3.22 8.98 0.31082

-38 1.3 16.0 0.011389 3.14 87.80 0.31835

-37 1.7 16.4 0.011402 3.07 87.70 0.32602

-36 2.2 16.9 0.011415 3.00 87.60 0.33384

Page 51: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 51 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

-35 2.5 17.2 0.011428 2.93 87.50 0.34181

-34 3.0 17.7 0.011442 2.86 87.40 0.34992

-33 3.5 18.2 0.011455 2.79 87.30 0.35818

-32 3.7 18.4 0.011469 2.73 87.19 0.36660

-31 4.4 19.1 0.011482 2.67 87.09 0.37517

-30 4.9 19.6 0.011495 2.60 86.99 0.38389

-29 5.4 20.1 0.011509 2.55 86.89 0.39278

-28 5.9 20.6 0.011523 2.49 86.78 0.40182

-27 6.5 21.2 0.011536 2.43 86.69 0.41103

-26 6.9 21.6 0.011550 2.38 86.58 0.42040

-25 7.4 22.1 0.011564 2.33 86.48 0.42993

-24 7.9 22.6 0.011578 2.27 86.37 0.43964

-23 8.5 23.2 0.011592 2.22 86.27 0.44951

-22 9.0 23.7 0.011606 2.18 86.16 0.45956

-21 9.6 24.3 0.011620 2.13 86.06 0.46978

-20 10.1 24.8 0.011634 2.08 85.95 0.48018

-19 10.7 25.4 0.011548 2.04 86.59 0.49075

-18 11.3 26.0 0.011662 1.99 85.75 0.50151

-17 11.9 26.6 0.011677 1.95 85.64 0.51245

-16 12.5 27.2 0.011691 1.91 85.54 0.52358

-15 13.2 27.9 0.011705 1.87 85.43 0.53489

-14 13.8 28.5 0.011720 1.83 85.32 0.54640

-13 14.5 29.2 0.011734 1.79 85.22 0.55810

-12 15.1 29.8 0.011749 1.75 85.11 0.56999

-11 15.8 30.5 0.011764 1.72 85.01 0.58207

-10 16.5 31.2 0.011778 1.68 84.90 0.59436

-9 17.5 32.2 0.011793 1.65 84.80 0.60685

-8 17.9 32.6 0.011808 1.61 84.69 0.61954

-7 18.6 33.3 0.011823 1.58 84.58 0.63244

-6 19.3 34.0 0.011838 1.55 84.47 0.64555

-5 20.1 34.8 0.011853 1.52 84.37 0.65887

-4 20.8 35.5 0.011868 1.49 84.26 0.67240

-3 21.6 36.3 0.011884 1.46 84.15 0.68615

-2 22.4 37.1 0.011899 1.43 84.04 0.70012

-1 23.2 37.9 0.011914 1.40 83.93 0.71431

0 24.0 38.7 0.011930 1.37 83.82 0.72878

Page 52: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 52 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

1 24.8 39.5 0.011945 1.35 83.72 0.74336

2 25.6 40.3 0.011961 1.32 83.61 0.75822

3 26.5 41.2 0.011976 1.29 83.50 0.77332

4 27.3 42.0 0.011992 1.27 83.39 0.78865

5 28.2 42.9 0.012008 1.24 83.28 0.80422

6 29.1 43.8 0.012024 1.22 83.17 0.82003

7 30.0 44.7 0.012040 1.20 83.06 0.83608

8 30.9 45.6 0.012056 1.17 82.95 0.85237

9 31.8 46.5 0.012072 1.15 82.84 0.86892

10 32.8 47.5 0.012088 1.13 82.73 0.88571

11 33.7 48.4 0.012105 1.11 82.61 0.90275

12 34.7 49.4 0.012121 1.09 82.50 0.92005

13 35.7 50.4 0.012138 1.07 82.39 0.93761

14 36.7 51.4 0.012154 1.05 82.28 0.95544

15 37.7 52.4 0.012171 1.03 82.16 0.97352

16 38.7 53.4 0.012188 1.01 82.05 0.99188

17 39.8 54.5 0.012204 0.990 81.94 1.0105

18 40.9 55.6 0.012221 0.971 81.83 1.0294

19 41.9 56.6 0.112238 0.954 81.91 1.0486

20 43.0 57.7 0.012255 0.936 81.60 1.0680

21 44.1 58.8 0.012290 0.910 81.37 1.0989

22 45.3 60.0 0.012290 0.903 81.37 1.1078

23 46.4 61.1 0.012307 0.886 81.25 1.1281

24 47.6 62.3 0.012325 0.871 81.14 1.1487

25 48.8 63.5 0.012342 0.855 81.02 1.1696

26 49.9 64.6 0.012360 0.840 80.91 1.1908

27 51.2 65.9 0.011238 0.825 88.99 1.2123

28 52.4 67.1 0.012395 0.810 80.68 1.2341

29 53.6 68.3 0.012413 0.796 80.56 1.2562

30 54.9 69.6 0.012431 0.782 80.44 1.2786

31 56.2 70.9 0.012450 0.768 80.32 1.3014

32 57.5 72.2 0.012468 0.755 80.21 1.3244

33 58.8 73.5 0.012486 0.742 80.09 1.3478

34 60.1 74.8 0.012505 0.729 79.97 1.3715

35 61.5 76.2 0.012523 0.717 79.85 1.3956

Page 53: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 53 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

36 62.8 77.5 0.012542 0.704 79.73 1.4199

37 64.2 78.9 0.012561 0.692 79.61 1.4447

38 65.6 80.3 0.012579 0.668 79.50 1.4967

39 67.1 81.8 0.012598 0.669 79.38 1.4951

40 68.5 83.2 0.012618 0.665 79.25 1.5028

41 70.0 84.7 0.012637 0.647 79.13 1.5469

42 71.5 86.2 0.012656 0.636 79.01 1.5734

43 73.0 87.7 0.012676 0.625 78.89 1.6002

44 74.5 89.2 0.012695 0.615 78.77 1.6274

45 76.0 90.7 0.012715 0.604 78.65 1.6549

46 77.6 92.3 0.012735 0.594 78.52 1.6829

47 79.2 93.9 0.012755 0.584 78.40 1.7112

48 80.8 95.5 0.012775 0.575 78.28 1.7398

49 82.4 97.1 0.012795 0.565 78.16 1.7689

50 84.0 98.7 0.012815 0.556 78.03 1.7998

51 85.7 100.4 0.012836 0.547 77.91 1.8282

52 87.4 102.1 0.012856 0.538 77.78 1.8585

53 89.1 103.8 0.012877 0.529 77.66 1.8891

54 90.8 105.5 0.012898 0.521 77.53 1.9202

55 92.6 107.3 0.012919 0.512 77.41 1.9517

56 94.3 109.0 0.012940 0.504 77.28 1.9836

57 96.1 110.8 0.012961 0.496 77.15 2.0159

58 97.9 112.6 0.012982 0.488 77.03 2.0486

59 99.8 114.5 0.013004 0.480 76.90 2.0818

61 103.5 118.2 0.013047 0.465 76.65 2.1495

62 105.4 120.1 0.013069 0.458 76.52 2.1840

63 107.3 122.0 0.013091 0.451 76.39 2.2190

64 109.3 124.0 0.013114 0.444 76.25 2.2544

65 111.2 125.9 0.013136 0.437 76.13 2.2903

66 113.2 127.9 0.013159 0.430 75.99 2.3266

67 115.2 129.9 0.013181 0.423 75.87 2.3635

68 117.3 132.0 0.013204 0.417 75.73 2.4008

69 119.3 134.0 0.013227 0.410 75.60 2.4386

70 121.4 136.1 0.013251 0.404 75.47 2.4769

71 123.5 138.2 0.013274 0.398 75.34 2.5157

72 125.7 140.4 0.013297 0.391 75.20 2.5550

73 127.8 142.5 0.013321 0.385 75.07 2.5948

74 130.0 144.7 0.013345 0.380 74.93 2.6351

75 132.2 146.9 0.013369 0.374 74.80 2.6760

Page 54: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 54 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

76 134.5 149.2 0.013393 0.368 74.67 2.7174

77 136.7 151.4 0.013418 0.364 74.53 2.7493

78 139.0 153.7 0.013442 0.357 74.39 2.8018

79 141.3 156.0 0.013467 0.352 74.26 2.8449

80 143.6 158.3 0.013492 0.346 74.12 2.8885

81 146.0 160.7 0.013492 0.341 74.12 2.9326

82 148.4 163.1 0.013518 0.336 73.98 2.9774

83 151.8 166.5 0.013569 0.332 73.70 3.0117

84 153.2 167.9 0.013594 0.326 73.56 3.0686

85 155.7 170.4 0.013620 0.321 73.42 3.1151

86 155.7 170.4 0.013647 0.316 73.28 3.1622

87 158.2 172.9 0.013673 0.312 73.14 3.2100

88 161.7 176.4 0.013700 0.307 72.99 3.2583

89 163.2 177.9 0.013727 0.302 72.85 3.3073

90 168.4 183.1 0.013754 0.298 72.71 3.3570

91 171.0 185.7 0.013781 0.294 72.56 3.4073

92 173.7 188.4 0.013809 0.289 72.42 3.4582

93 176.4 191.1 0.013836 0.285 72.28 3.5098

94 179.1 193.8 0.013864 0.281 72.13 3.5621

95 181.8 196.5 0.013893 0.277 71.98 3.6151

96 184.6 199.3 0.013921 2.726 71.83 0.3669

97 187.4 202.1 0.013950 0.269 71.68 3.7232

98 190.2 204.9 0.013979 0.265 71.54 3.7783

99 193.0 207.7 0.014008 0.261 71.39 3.8341

100 195.9 210.6 0.014038 0.257 71.24 3.8907

101 198.8 213.5 0.014068 0.253 71.08 3.9481

102 201.8 216.5 0.014098 0.250 70.93 4.0062

103 204.7 219.4 0.014128 0.246 70.78 4.0651

104 207.7 222.4 0.014159 0.242 70.63 4.1247

105 210.8 225.5 0.014190 0.239 70.47 4.1852

106 213.8 228.5 0.014221 0.231 70.32 4.3265

107 216.9 231.6 0.014253 0.232 70.16 4.3086

108 220.0 234.7 0.014285 0.229 70.00 4.3715

109 223.2 237.9 0.014317 0.226 69.85 4.4354

110 226.4 241.1 0.014350 0.222 69.69 4.5000

Refrigerant HCFC-22

Page 55: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 55 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

111 229.6 244.3 0.014382 0.219 69.53 4.5656

112 232.8 247.5 0.014416 0.216 69.37 4.6321

113 236.1 250.8 0.014449 0.213 69.21 4.6994

114 239.4 254.1 0.014483 0.210 69.05 4.7677

115 242.7 257.4 0.014517 0.207 68.88 4.8370

116 246.1 260.8 0.014552 0.204 68.72 4.9072

117 249.5 264.2 0.014587 0.201 68.55 4.9784

118 252.9 267.6 0.014622 0.198 68.39 5.0506

119 256.4 271.1 0.014658 0.195 68.22 5.1238

120 259.9 274.6 0.014694 0.192 68.05 5.1981

121 259.9 274.6 0.014731 0.190 67.88 5.2734

122 263.4 278.1 0.014768 0.187 67.71 5.3498

123 267.0 281.7 0.014805 0.184 67.54 5.4272

124 270.6 285.3 0.014843 0.182 67.37 5.5058

125 277.9 292.6 0.014882 0.179 67.20 5.5856

126 281.6 296.3 0.014882 0.177 67.20 5.6665

127 285.4 300.1 0.014920 0.174 67.02 5.7486

128 289.1 303.8 0.014960 0.172 66.84 5.8319

129 296.0 310.7 0.015039 0.169 66.49 5.9164

130 296.8 311.5 0.015080 0.167 66.31 6.0022

131 300.7 315.4 0.015121 0.164 66.13 6.0893

132 304.6 319.3 0.015163 0.162 65.95 6.1777

133 308.6 323.3 0.015206 0.160 65.76 6.2674

134 312.5 327.2 0.015248 0.157 65.58 6.3585

135 316.6 331.3 0.015292 0.155 65.39 6.4510

136 320.6 335.3 0.015336 0.153 65.21 6.5450

137 324.7 339.4 0.015381 0.151 65.02 6.6405

138 328.9 343.6 0.015426 0.148 64.83 6.7374

139 333.0 347.7 0.015472 0.146 64.63 6.8359

140 337.3 352.0 0.015518 0.144 64.44 6.9360

141 341.5 356.2 0.015566 0.142 64.24 7.0377

142 345.8 360.5 0.015613 0.140 64.05 7.1410

143 350.1 364.8 0.015662 0.138 63.85 7.2461

144 354.5 369.2 0.015712 0.136 63.65 7.3529

145 358.9 373.6 0.015762 0.134 63.44 7.4615

Page 56: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 56 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

146 363.3 378.0 0.015813 0.132 63.24 7.5719

147 367.8 382.5 0.015865 0.130 63.03 7.6842

148 372.3 387.0 0.015917 0.128 62.83 7.7985

149 376.9 391.6 0.015971 0.126 62.61 7.9148

150 381.5 396.2 0.016025 0.123 62.40 8.1331

151 386.1 400.8 0.016080 0.123 62.19 8.1536

152 390.8 405.5 0.016137 0.122 61.97 8.1763

153 395.6 410.3 0.016194 0.119 61.75 8.4011

154 400.3 415.0 0.016252 0.117 61.53 8.5284

155 405.1 419.8 0.016312 0.116 61.30 8.6580

156 410.0 424.7 0.016372 0.114 61.08 8.7911

157 414.9 429.6 0.016434 0.112 60.85 8.9247

158 419.8 434.5 0.016497 0.110 60.62 9.0620

159 424.8 439.5 0.016561 0.109 60.38 9.2020

160 429.8 444.5 0.016627 0.107 60.14 9.3449

161 434.9 449.6 0.016693 0.105 59.91 9.4907

162 440.0 454.7 0.016762 0.104 59.66 9.6395

163 445.2 459.9 0.016831 0.102 59.41 9.7915

164 450.4 465.1 0.016902 0.106 59.16 9.3947

165 455.6 470.3 0.016975 0.0990 58.91 10.106

166 460.9 475.6 0.017050 0.0974 58.65 10.268

167 466.3 481.0 0.017126 0.0958 58.39 10.434

168 471.7 486.4 0.017204 0.0943 58.13 10.603

169 477.1 491.8 0.017285 0.0928 57.85 10.777

170 482.6 497.3 0.017367 0.0913 57.58 10.955

171 488.1 502.8 0.017451 0.0898 57.30 11.138

172 493.7 508.4 0.017538 0.0883 57.02 11.325

173 499.6 514.3 0.017627 0.0868 56.73 11.517

174 505.0 519.7 0.017719 0.0854 56.44 11.714

175 510.7 525.4 0.017813 0.0837 56.14 11.947

176 516.5 531.2 0.117910 0.0825 8.48 12.125

177 522.3 537.0 0.018011 0.0810 55.52 12.340

178 528.2 542.9 0.018114 0.0796 55.21 12.560

179 534.1 548.8 0.001822 0.0782 548.82 12.788

180 540.1 554.8 0.018332 0.0768 54.55 13.023

Page 57: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 57 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Refrigerant HCFC-22

Temp in

Degrees

Fahrenheit

(°f)

Gauge

Pressure

psig *

Absolute

Pressure

psia

Specific

Volume

liquid

cu.ft./lb.

Specific

Volume

Vapor

cu.ft./lb.

Density

Liquid

lbs./cu.ft.

Density

Vapor

lbs./cu.ft.

181 546.1 560.8 0.018447 0.0754 54.21 13.265

182 552.2 566.9 0.018566 0.0740 53.86 13.516

183 558.4 573.1 0.018690 0.0726 53.50 13.776

184 564.5 579.2 0.018820 0.0712 53.13 14.045

185 570.8 585.5 0.018954 0.0698 52.76 14.324

186 577.1 591.8 0.019095 0.0684 52.37 14.615

187 598.2 612.9 0.019243 0.0670 51.97 14.918

188 604.6 619.3 0.019397 0.0656 51.55 15.235

189 611.1 625.8 0.019561 0.0642 51.12 15.566

190 617.5 632.2 0.019733 0.0628 50.68 15.914

191 624.2 638.9 0.019915 0.0614 50.21 16.280

192 630.8 645.5 0.020110 0.0600 49.73 16.667

193 637.6 652.3 0.020647 0.0586 48.43 17.077

194 644.3 659.0 0.020540 0.0571 48.69 17.514

195 651.2 665.9 0.020782 0.0556 48.12 17.983

196 658.1 672.8 0.021045 0.0541 47.52 18.488

197 665.1 679.8 0.021334 0.0525 46.87 19.038

198 657.4 672.1 0.021655 0.0509 46.18 19.642

199 664.5 679.2 0.022048 0.0492 45.36 20.315

200 671.7 686.4 0.022436 0.0474 44.57 21.080

Page 58: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 58 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

An Integrated Approach to

Efficient Industrial Refrigeration Systems Lighting

This section of the CRES Study Guide will NOT be

available during the CRES exam. Questions based on this

information must be answered from memory during the

test.

Reprinted with permission from ASW Engineering.

Page 59: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 59 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Lamp Performance Criteria

There are several useful measures of lamp performance that can be used to compare the products offered by different manufacturers. Some are:

• Light output and power input

• Color characteristics including Correlated Color Temperature (CCT) and Color Rendering Index (CRI)

• Lamp life (lamp depreciation)

• Lumen depreciation

Light Output One measure of lamp performance is light output. For most lamps, output is measured in total lumens or overall light output. Lumens is defined as the amount of light generated by a light source. For directional light sources (such as reflector lamps) light output (or the luminous intensity) is measured in candlepower or candelas (cd). This is the directional intensity of light from a point source.

Lamp efficacy is defined as the ratio of lumens of light output to total watts of input power (efficacy = lumens/watts) and is the best way to measure a lamp’s energy efficiency. Efficacy is a term that also can be used to assess the energy efficiency of an entire lighting system. The higher the efficacy the better, because that means we are getting more light (lumens) per watt.

A lumen is an amount of light generated by a light source. Lamps are rated according to the number of lumens they produce. (A standard 60-watt incandescent lamp generates about 890 lumens.)

A footcandle is the amount of light that reaches a particular surface. You measure footcandles with a light meter.

These concepts assume that a candle uniformly distributes light in all directions. Given a sphere with a radius of one foot surrounding the candle, a lumen is the amount of light that would pass through a one square foot opening in the sphere.

Page 60: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 60 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Energy Consumption

Different lamps are rated for lumen output and lamp life under strict standards set by the American National Standards Institute (ANSI). The ratings are based on specific combinations of voltage, mounting orientation, ballast, and ambient air temperature. Differences in any of these conditions can affect both input power requirements and light output, which in turn will affect efficacy.

Typical efficacy (lumens/watt) of example light sources

Standard incandescent

Tungsten- halogen

Halogen infrared reflecting

Compact fluorescent (5–26 W)

LEDs Compact fluorescent (27–40 W)

Full-size fluorescent

lumens/watt

lumens/watt umens/watt

umens/watt

lumens/watt

Page 61: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 61 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Color Characteristics

There are two common ways to describe the color of a lamp’s light:

• Chromaticity and Correlated Color Temperature (CCT)

• Color Rendering Index (CRI)

Correlated Color Temperature

Chromaticity is expressed by Correlated Color Temperature (CCT) (or simply color temperature) and measures the apparent color of a light source. CCT measures in degrees Kelvin (K) the chromaticity or color of a light source.

Color temperature describes how warm or cool a light source appears. A warm color is a low number (3000 K) and a cool color is a higher number (5000 K). A color temperature around 5000 K is well-suited for use in refrigerated warehouses.

Color temperature can be thought of as the measurement used to describe the “tint” of white light. The color temperature of a light source is measured to determine light quality.

Tungsten

halogen 40-watt

incandescent lamp

Candle

9000 -

8500 -

8000 -

7500 -

7000 -

6500 -

6000 -

5500 -

5000 -

4500 -

4000 -

3500 -

3000 -

2500 -

2000 -

1500 -

North light blue sky

Overcast sky

Daylight fluorescent

Clear mercury

Summer sunlight

Metal halide

Cool white

White

Warm white; Metal halide

High pressure sodium lamps

Low pressure sodium lamps

Color temperature chart

Ke

lvin

Page 62: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 62 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

The table below shows some lighting-level ranges based on recommendations from the Illuminating Engineering Society of North America.

Recommended Illumination Levels for Various Activities

Type of Lighting Type of Activity Recommended Illumination Level

General or Background (throughout spaces)

Public spaces 2 - 5 footcandles

Simple orientation 5 - 10 footcandles

Task Lighting (at workstations)

Working spaces; occasional visual tasks

10 - 20 footcandles

Visual tasks; high contrast, or large size

20 - 50 footcandles

Visual tasks; medium contrast, or small size

50 - 100 footcandles

Visual tasks; low contrast, or very small size

100 - 200 footcandles

Recommended illumination levels for various activities (based on recommendations from the Illuminating Engineering Society of North America)

If you think you have more lighting than you need, you can reduce it either by “delamping” (removing lamps) or by replacing existing lamps with lower wattage or higher efficiency lamps.

Whether you are removing or replacing lamps, you can use one of two general approaches to reduce lighting levels:

• Experiment.

− Begin with hallway or general lighting levels and remove or replace a few lamps at a time.

− Continue to adjust the number or type of lamps until you find a combination that provides just enough light for the location.

• Take footcandle readings.

− Use a light meter to take readings at the level where work is done.

− Use a footcandle table as a guide.

− Remove or replace lamps until you get a reading in the desired range.

Regardless of which method you use, bear in mind the factors of safety and comfort, and use common sense.

Page 63: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 63 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Lighting in Refrigerated Facilities

Let’s look at a few of the typical lighting types that are suggested for use in refrigerated facilities.

• Flourescent lamps (T-8 and T-5)

• High intensity discharge (HID) lamps

• LED lamps

High Bay Fluorescent Lighting in Refrigerated Facilities

T-8 and T-5 high bay lamps have advantages over high intensity discharge (HID) lamps.

One key advantage is that T-8s and T-5s have instant start capability. HID lamps, such as metal halide, high pressure sodium, and mercury vapor lamps, take a long time to warm up. This characteristic makes it impractical to turn them off in empty spaces. Product handlers and forklift operators don’t like waiting 10 to 15 minutes for the lighting to warm up to full brightness.

Like the T-8s and T-5s, LEDs also have instant start capability. This means all of these can be controlled using motion or occupancy sensors.

In many situations, using sensors and high bay fluorescent or LED lighting can reduce the hours of operation of lights in refrigerated facilities from 10 to 12 hours a day to less than 4 hours a day. This could easily reduce lighting costs by half.

Reduced Heat Gain

Whenever a lower wattage lamp is retrofit in a refrigerated space, energy is not only saved from the lighting itself but also from the reduced heat gain.

Each kWh of lighting savings is 3,413 fewer BTUs of heat in the refrigerated space, and thus creates additional savings at the compressor.

Page 64: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 64 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Fluorescent Lamps

The great advantages of a fluorescent light are its high light output per watt and its long life.

Fluorescent lamp manufacturers have responded to the rising costs of energy by developing lamps that are more efficient and flexible in application than the original standard series.

• The new compact fluorescent lamps are becoming more versatile and consume much less electricity.

• Color-corrected fluorescent lamps (such as “warm white” and “deluxe cool white”) are useful in many applications that were previously limited to incandescent lamps.

Before discussing the detailed considerations for using fluorescent lamps to replace incandescent lamps, you should know a little bit about how fluorescent lamps work.

How Fluorescent

Lamps Work

A fluorescent light uses a fluorescent phosphor coating inside its tube. An electric current is applied to electrodes that are positioned at each end of the lamp which causes an arc to jump from one end of the lamp to the other. In the process, ultraviolet radiation is emitted. When the radiation strikes the phosphor coating, the phosphors begin to fluoresce (emit visible light).

Since the resistance of the arc decreases as current increases, the current would destroy the lamp if not controlled. Also, in a fluorescent light circuit, a relatively high voltage (one to three hundred volts) is required to initiate the arc, and a much lower voltage is needed to maintain the arc and keep the lamp lighted.

Fluorescent lamp operation

1. Electrons emitted from the electrode collide with an electron of a mercury atom.

2. Ultraviolet radiation is produced.

3. Phosphor crystals fluoresce and emit visible light.

Page 65: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 65 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

High Output (HO) Rapid Start Lamps

Instant Start (Slimline) Lamps

Rapid Start and Preheat Lamps

T-12

T-10

T-8

T-5

Comparing Fluorescent Alternatives

Next, we will describe a few fluorescent alternatives and discuss some of their features and relative benefits. First, let’s look at the full length fluorescent options. T-8 fluorescent lamps are full-size lamps. They were introduced in the United States in 1982, and are now made by all major U.S. lamp manufacturers. T-8 lamps are available in several straight-tube and U-bent configurations.

Like standard F40T12 (T-12) lamps, T-8 lamps are rated at 20,000 hours for 60 Hz rapid start. For highest effectiveness, they are often matched with electronic ballasts. These operate the lamps in an instant start mode and at 25,000 Hz. (Electronic ballasts for rapid start operation are also available.)

T-8 lamps offer several advantages over the standard T-12 lamps:

• Two-lamp T-8 systems with an instant start electronic ballast can attain up to 90 lumens per watt, compared to a two-lamp T-12 system at about 78 lumens per watt.

• All T-8 lamps contain rare earth phosphors which means better color rendering and lamp lumen maintenance when compared to T-12 halophosphor lamps— phosphors “love” high frequency. (Lumen maintenance is a measure of how well a lamp maintains its lamp output as it ages and is usually expressed as a curve.)

• T-8 lamps are about the same price as T-12 lamps.

• Unlike T-12 lamps which have a tendency to trap light, T-8 lamps allow more light to escape from the lamp.

Standard fluorescent lamp bases

A fluorescent lamp’s ballast is in effect a small transformer that:

Dia

me

ter

1 ½

in

ch

1 ¼

in

ch

1 inch

5/8

inch

1 ½

in

ch

1 inch

1 ½

in

ch

Page 66: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 66 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Ballasts A type of inductor known as a ballast serves both needs for high and low voltage. It limits the current; and, for most sizes, it increases the voltage for reliable starting and stable operation. Lamps of different sizes require different ballasts.

ies the correct voltage that is needed to start an arc between the two electrodes.

• Controls the electric current needed to maintain light output.

Magnetic vs. Electronic

Ballasts

There are two fundamental ballast designs. Traditionally, fluorescent lamps used electromagnetic (or simply “magnetic”) ballasts. The relatively recent electronic (or simply “electric”) ballasts can help save energy. The specific ballast used has a significant impact on a fluorescent lamp’s energy efficiency.

According to the Electric Power Research Institute (EPRI):“High-frequency electronic ballasts increase the energy efficiency of fluorescent lighting systems 6% to 29% compared to systems using electromagnetic ballasts. Upgrading to T- 8 lamps at the same time can improve energy efficiency by up to 59%.” That’s a considerable improvement.

The reason that electric ballasts are so energy efficient is that they use electronic components. These reduce internal electricity losses, and let the lamps operate at high frequencies—between 20,000 and 60,000 Hz. Higher frequencies increase lamp effectiveness by about 10% over lamps operated at 60 Hz by electromagnetic ballasts.

One easy way to check the type of ballast installed is to use a “strobe top.” When you spin this top under the fluorescent lamps, if you can see pattern lines, it is a magnetic ballast; if the pattern is smooth with no lines, it is a high-frequency electronic ballast.

Another type is the dimmable (or “dimming”) ballast, which we will discuss later.

Standard magnetic and electronic ballasts

Page 67: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 67 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

T-5 Lamps T-5 lamps, which are 5/8” in diameter, have improved phosphors and are part of a new generation of lamps that offer improved efficacy and optical control when compared to T-12 and T-8 lamps.

T-5 lamps can be up to 18% more efficient than T-8 systems, have lumen maintenance as high as 97%, and provide a high optimal operating temperature that improves performance in enclosed fixtures. Also, T-5 lamps and ballasts are much thinner than T-12’s and T-8’s and present sleeker and more contemporary fixtures. T-5 lamps are used with specially designed, high frequency electronic ballasts for optimum performance.

T-5’s originated in Europe and have metric lengths—they are about two inches shorter than comparable T-8 and T-12 bi-pin U.S. lamps. A typical 1,150 mm T-5 has a lifetime of 16,000 hours and generates 2,900 initial lumens. One example lamp provides system efficacy over 100 lumens per watt, a CRI of 85, and is available in color temperatures of 3,000, 3,500, and 4,000 K.

Other T-5 lamps have a rated life of 20,000 hours and come in standard sizes of 14, 21, 28, and 35 watts. HO (High Output) sizes are 24, 39, and 54 watts.

T-5 lamps (Sylvania)

Page 68: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 68 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

T-5 Applications T-5 lamps can be used in a variety of applications, including:

• Indirect suspended luminaires

• Direct/indirect lay-in luminaires

• Cove and valence lighting

• Wall washing

System Comparison—T-12/SS vs. OCTRON T-8 vs. PENTRON T-5

Lamp Lamp Type

# Lamps

Ballast BF System Watts

Initial System Lumens

Lumen Maint.

Mean System Lumens

Relative Light

Output

Mean System

LPW

F40T12CW/S S

T12 2 Magnetic 0.88 72 4660 0.85 3960 100% 55

F032/841 T8 2 System 32 0.90 52 5310 0.92 4890 123% 83

FP28/841 T5 2 System PS 1.0 62 5200 0.93 4836 122% 78

FP54/841/HO T5 1 System PHO

1.0 61 4450 0.93 4140 105% 68

(Lamp data courtesy Osram Sylvania)

Page 69: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 69 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Example T-5 Lamp for Refrigerated Facilities

There are many T-5 lamps that are designed to operate in sub-freezing temperatures like those found in refrigerated facilities.

One typical example is manufactured by Precision Fluorescent.

Key features

• Lens assembly features closed cell neoprene gasketing and cam-lock latches; the sealed housing retains the heat produced by the lamps and ballasts

• Can be used down to -20° F

• Available in 4-lamp through 6-lamp 2 x 4 versions

• Peak light output at -10° F

Page 70: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 70 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

T-5 Industrial Fixtures and Applications

For warehouse and interior lighting, the recent trend in lighting systems is away from HPS (high pressure sodium) and toward industrial T-5 lighting. Older warehouse and interior lighting are being converted to linear fluorescent.

The old rule of thumb in the lighting industry says that for indoor settings, fluorescent lighting made the most sense for low ceilings below about 15 or 20 feet and high-intensity discharge (HID) lighting was the best choice for higher ceilings (high-bay applications). This is no longer the case.

Today’s high-output T-5 fluorescent lamps and specially designed high-bay fluorescent fixtures can now work well in the high-bay applications.

There are now at least a dozen fixture manufacturers who are producing high- bay fixtures for long twin-tube or straight-tube T-5 lamps. These fixtures typically come with four to eight of the very bright T-5 lamps in a relatively small luminaire with high-efficiency reflectors that deliver almost all of the light output downward.

Replacing metal halide HID high-bays with T-5 high-bays can provide energy savings of 50% or more. The savings are a result of the features of the newer T-5 fixtures:

• Lower wattage lamps and ballasts

• Higher lumens per watt

• The improved fixture efficiency

• The higher ballast efficiency

T-5 Industrial fixture

Page 71: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 71 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Page 72: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 72 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

High Intensity Discharge (HID) Lamps

While fluorescent lighting is approximately four times as efficient as incandescent lighting, the newer high intensity discharge (HID) lamps are even more efficient. HID lighting is found in outdoor lighting and in a variety of work areas, including warehouses, parking garages, gymnasiums, and retail settings.

HID lighting has been around for over 100 years. HID lamps produce light with an electric arc through a tube that contains gases. Like fluorescent lamps, HID lamps require a ballast for starting and operating the lamp. HID lamps generally have a good to excellent CRI and are available in sizes from 39 W to 1500 W.

Included in this lighting group are Mercury Vapor (MV), Metal Halides (MH), Low Pressure Sodium (LPS), and High Pressure Sodium (HPS).

• Mercury vapor is the oldest type of HID lighting. It is mostly used for street lighting. Most indoor mercury vapor lighting has been replaced with metal halide lighting, which has better color rendering and efficiency.

• Metal halide lamps are similar to mercury vapor lamps and are used in large indoor areas such as gymnasiums and sports arenas, and for outdoor areas. Compared with mercury vapor lamps, metal halide lamps have higher light output, more lumens per watt, and better color rendition. The first metal halide lamp was developed about 1960.

• Low-pressure sodium lamps provide the most efficient artificial lighting, have the longest service life, and maintain their light output better than any other type of lamp. Low-pressure sodium lighting is used where color is not important such as highway and security lighting.

• High pressure sodium (HPS) lamps:

− Typically emit a golden white light (not to be confused with the distinctive yellowish light of the Low Pressure Sodium lamps). HPS lamps do distort some colors (reds have a brownish hue), but all colors remain recognizable.

− Are used extensively outdoors and are also gaining acceptance for indoor applications where color is not critical to task performance.

− Are available in a color-corrected version that produces color rendering properties similar to very “warm” incandescent. The trade- off is that they are somewhat less efficient and shorter lived than the standard HPS.

Significant energy savings are possible by replacing old mercury vapor lamps with newer metal halide or high pressure sodium lamps. For retrofitting inside high-bay or any outdoor lighting fixtures, of the different types of HID lamps, the high pressure sodium lamps appear to provide the most versatile and cost- effective alternative. High-pressure sodium lighting is becoming the most popular type of outdoor lighting.

Page 73: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 73 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Typically, in situations that warrant consideration of complete incandescent fixture replacement, the application of HPS can reduce energy consumption by approximately 40-50% for the lower illumination level requirements.

As an example, for an existing 100 W incandescent application, using a 35 W HPS will produce slightly less light, while using a 50 W HPS will provide more light.

Alternatively, in situations where the “yellowish” color of Low Pressure Sodium (LPS) lamps is not objectionable, there are 18 W units available that can deliver the light equivalent of a 150 W incandescent lamp. This represents about an 80% energy reduction (even after accounting for the LPS ballast loss).

However, there are some drawbacks to typical metal halide lamps:

• Metal halide lamps emit high levels of UV radiation that must be shielded by glass in the lamp or fixture.

• Their high intensity limits the range of application for metal halide lamps and requires the use of sophisticated fixtures.

• They require a start-up period after a shutdown or power interruption.

HID Lamp Warm-up Time

Although HID lighting is popular, most HID lamps take several minutes to reach full light output. This makes them less amenable to automatic control, and they cannot be efficiently switched off and on without creating inconvenience for occupants. (Some lamps over 400 watts are available with instant restrike capability, but they require special ballasts.)

Depending on the type of lamp, HID lamps may need from one minute to as much as 15 minutes for a “restrike.” (Restrike refers to turning the light back on after it has been turned off.) For example, a typical low pressure sodium lamp requires 7 to 15 minutes for a “cold” restrike but less than one minute for a “hot” restrike.

During the warm-up period the gases used to create the lighting arc rise to the necessary temperatures.

Type of HID lamp Time to warm up (“cold” restrike)

Cold-start mercury vapor lamps 5 – 7 minutes

Low pressure sodium 7 – 15 minutes

High pressure sodium 3 – 5 minutes

Metal halide 2 – 5 minutes

Page 74: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 74 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

LED Lamps There are two basic types of LEDs:

• Discrete LEDs

• Chip LEDs

The discrete package, also called the “through-hole” LED, is the most common. Its packaging includes a reflector to gather and focus the light and a plastic dome envelope, which determines the beam-spread and protects the LED.

The surface mount chip packaging consists of only a flat plastic lens. Chip LEDs are micro-soldered to a circuit board and, because they have no reflector or dome envelope, provide a wider beam spread at lower intensity than discrete LEDs.

LED Exit Signs Significant technology developments during the past few years have reduced the cost and improved the practicality of LED exit signs. Second-generation LEDs have been developed that are up to 30 times as bright as earlier ones.

The higher light output allows the LEDs to be used in exit sign boxes in the same way as incandescent and fluorescent lamps, instead of using the LEDs in direct view to spell “EXIT.” The use of strips of LEDs or LED lamps makes them feasible for retrofit applications. LED Exit Sign Retrofit Kit are designed for retrofitting either incandescent or compact fluorescent exit signs and can consume as little as 1.5 watts.

Exit sign and LED lamp and base adapters

Page 75: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 75 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

Exits Signs — Typical Costs

Fixture Typical

wattage

Life (yrs.) Annual energy

costs at $0.10/kWh

Maint. costs First costs

(materials

only)

Life cycle cost

1 yr. 5 yr. 10 yr. 15 yr.

Incandescent 40 0.8 $35.00 $19.50 $25 $80 $298 $570 $843

CFL 10 2 $ 8.75 $ 9.50 $60 $78 $151 $243 $334

LED 4 10 $ 3.50 $ 0.00 $45 $49 $63 $125 $143

(EPA)

This data provided by the EPA assumes that installation labor is the same for all three technologies, so only

the cost of the signs is used. Note that the first costs of LED exit signs has fallen dramatically in recent years

and is competitive with incandescent exit signs.

Manufacturer’s estimates of the life of LED lamps generally range from 30,000 to 100,000 hours depending

on the type and the color. For example, red LEDs have a rated life up to 10 times longer than white LEDs.

(100,000 hours is a little over 34 years at 8 hours per day.) It is possible that the actual life is longer. One

manufacturer claims that 80 to 100 years is a reasonable expectation.

Typical fluorescent or incandescent lamps are given a “rated lamp life” which is based on standard tests that

document the number of lamps that fail. On the other hand, LEDs don’t really fail; instead they begin to

“fade away,” but continue to operate. This means new test methods will need to be developed to measure the

useful life of LEDs. The latest generation of LEDs have a longer life and operate at about 85% of their

original output after about 20,000 hours.

LEDison® series LED lamps

Page 76: RETA CRES Study Guide...2019/08/07  · CRES Study Guide Page 3 of 76 ©2019 Refrigerating Engineers & Technicians Association (RETA) The following screens show how this will work

CRES Exam Study Guide Page 76 of 75

©2019 Refrigerating Engineers & Technicians Association (RETA)

The optical control is a distinct advantage for this type of LED, in that the array of lenses can be customized to control the beam of light to point it at desired areas and avoid illuminating areas that are not desired. LED’s also function well under cold temperatures and restrike instantly from an off state.