DESCRIPTION SPECIFICATIONS - Atkinson Electronics · · 2009-01-26ORDERING EXAMPLES PSIM/DDC/MAS PSIM Module configured for Smart I I ... If you have a different application or

PHOENIX STAEFA INTERFACE MODULE PSIM

ATKINSON ELECTRONICS, INC. REV 5/0314 West Vine Street, Murray, UT 84107Phone (801) 262-6400, 1-800-261-3602Fax (801) 261-3796, E-MAIL: [email protected]

DESCRIPTION SPECIFICATIONS

The PSIM was designed to interface PHOENIX CONTROLS SIZE: 6.75" L x 2.8" W x 1.25" HCORP'S, valve or panel mounted MAC card to STAEFA'SSmart II DDC, FNC, or MUX 8620 series cards. The PSIM WEIGHT: 10 0Z. W/ CBL-Amodule plugs directly into the four universal range module 1 lb. W/ CBL's A,B,C,Dsockets and utilizes the DPX-5 mounting holes for quick 1 lb. W/ CBL-A & OPT. BRD.and easy mounting on the Smart II card.

The PSIM module converts the Staefa Phase cut signal to BOARD TO BOARD POSTSa scaled 0 to 10V DC signal for Phoenix electronic T-Stat (supplied)override. The PSIM interface provides the necessary voltagedividers and range module resistence to scale the Phoenix POWER: +15V DC, .015A (15mA)feedback and status signals down or up to a 0 to 5V DC -15V DC, .010A (10mA)signal for the Smart II controller card, providing optimuminput resolution. The PSIM provides the range modules to OUTPUT SIGNALS: T-Stat signal 0-10V DCscale the Smart II T-30 room sensor to a temperature range SM2 inputs 0-5V DCof 62 to 82 deg. f into input #5 of the DDC card, or Smart IIT-30 duct sensor to 27 to 1018f into input #5 on the FNC AMBIENT TEMP: 0 to 50 Ccard.

The PSIM module is powered by the same ± 15V DC supplyas the Phoenix control equipment. The Smart II's powertransformer isolates the input section thus input commonand Power supply common are connected for a commonsignal reference. The Staefa phase cut signal is referencedto the AC line through the bridge rectifier thus the PSIMPhase Cut input is optically isolated to avoid any groundloop problems.

OPERATION

The PSIM inputs are jumper selectable allowing for variousinput combinations depending on what configuration andwhat terminal block you're wired to. The input signals arescaled down to 2.5V DC through level pots. This allows fora signal below 5V DC to be scaled up to 5V DC for maxresolution either by the op-amp on the PSIM (SM2 inputs#0,1,2,3) or by the op-amp on the Smart II board (inputs#4,5,6,& 7).

MOUNTING: 1/2" PANDUIT CBP50

o

SUB-COMPONENTS: IDC Cables:CBL-A,CBL-B,CBL-C, & CBL-D.Termination boards:STBD-PSIM

INPUT CONFIGURATION



PSIM/XXX/XXX/XXX

Termination Option CodeConfiguration Option Code

SMART IIs Type Code

ORDERING INFORMATION CABLE CODE OPTIONS

SMART II CODE OPTIONS

DDC - SMART II DDC 8620FNC - SMART II FNC 8620MUX - SMART II MUX 8620

CONFIGURATION CODE OPTIONS

MAS - MASTER includes; Phase-cut converter,scaling for feedback & status signals,custom scaling for inputs 0 & 5.

MAS/HOC - MASTER W/ Heating Override Controlincludes; Master options with HOC sub-card. HOC sub-card includes; TwoSPDT Relays, Two level Pots, and biasvoltage jumpers.

SLA - SLAVE includes only scaling for Phoenixfeedback, alarm, and status signals.

TERMINATION CODE OPTIONS

STBD - Screw Terminal Board

CBL - Cable (AMP-IDC connectors)

ORDERING EXAMPLES

PSIM/DDC/MAS PSIM Module configured for Smart IIDDC, with Phase-cut to 0 to 10V DCconverter, custom narrow rangetemperature scaling for SM2 input # 5.

PSIM/FNC/MAS PSIM Module configured for Smart IIFNC, with Phase-cut to 0 to 10V DCconverter, standard temperature scalingfor SM2 FNC.

PSIM/MUX/SLA PSIM Module configured for Smart IIMUX, with only scaling for Phoenixfeedback, alarm, and status signals.

CB-A-24 6 conductor 24" CableCB-A to Staefa SM2 BaseSupplied with PCIM card

CB-B-X 13 conductor cableCB-B to Phoenix MAC(Amp connector # 1-643813-3)

CB-C-X 8 conductor cableCB-C to Phoenix MAC(Amp connector # 643813-8)

CB-D-X 8 conductor CB-D to Phoenix MAC(Amp connector # 643813-8)

Cables CB-B, CB-C, CB-D are orderedseparate from the PSIM board.

X-Length 24 - 24 inches long36 - 36 inches long48 - 48 inches long72 - 72 inches long96 - 96 inches long

SCREW TERMINAL BOARD OPTION

Call for other calibration ranges and versions.

If you have a different application or need, please call 1-800-261-3602 and discuss your needs with our Sales Engineers.



COMPONENTS CONNECTIONS

VR0(IN0)....Input #0 Voltage Divider TrimmerVR1(IN1)....Input #1 Voltage Divider TrimmerVR2(IN2)....Input #2 Voltage Divider TrimmerVR3(IN3)....Input #3 Voltage Divider TrimmerVR4(IN4)....Input #4 Voltage Divider TrimmerVR5(IN5)....Input #5 Voltage Divider TrimmerVR6(IN6)....Input #6 Voltage Divider TrimmerVR7(IN7)....Input #7 Voltage Divider Trimmer

*...Clockwise adjustment decreases voltage output at test point

VR8............TOS Zero Level Adj.VR9............TOS Span Adj.

*...Clockwise adjustment increases level and span

Jp #0.........Connects Input #0 Op-Amp Output to CB-A-3Jp #1.........Bias's Input #5 Op-Amp for T-30NRJp #2.........Bias's Input #5 Op-Am for 2:1 GainJp #3.........Connects VR5(IN5) Output to SM2 #5.Jp #4.........Connects 4.64k Pullup Resistor to Input #5Jp #5.........Bias's Input #3 Op-Amp from 2:1 Gain to 3:1Jp #6.........TOS High/Low Output Selector

High - 0-3-10VDC/ Low 0-.9-3VDC

M-P............Bias's Input #6 Op-Amp for 2:1 Gain* Select WHEN Supply Feedback Voltage is GREATER Than 2.5VDC

M-V............Bias's Input #6 Op-Amp for 10:1 Gain* Select WHEN Supply Feedback Voltage is LESS than 2.5VDC, Then Adj. VR6 for .5V Output on TP-12 Instead of 2.5V.

OSJ 0-7.....Option Selection Jumper Selects WhichTerminals and Pin # for that Input.See PSIM Selection Guide for Options

CB-A - 6 pin IDC connector Smart II connectionsCB-B - 12 pin IDC connector4 (MAS) Phoenix Gex, Supply, and TOS connections4 (SLV) Phoenix hood 3&4 inputCB-C - 8 pin IDC connector, Phoenix hood 1 inputCB-D - 8 pin IDC connector, Phoenix hood 2 inputTP-13 Test Points/Simulator Unit Input

4 Master Configuration1-8 terminals wire to gex terminals (MAC TB-11-1-8)9-11 terminals wire to supply terminal (MAC TB-16-2)12 terminal wires to T-stat override (MAC 12-1)

4 Slave Configuration1-8 terminals wire to hood #3 terminals (MAC TB-X-1-8)9-12 terminals wire to hood #4 terminals

(MAC TB-X-5-6-7 or 8)

COMPONENTS AND CONNECTIONS SHOWN AREFOR REVISION “C” OF THE PSIM MODULE.



PSIM TERMINAL POINTS LISTING

PSIM Master VersionInput/Output Terminal Convectors (IDC.1)

CB-A-1 + input for Staefa phase cut signalCB-A-2 y input for Staefa phase cut signalCB-A-3 Signal output to Staefa input #0CB-A-4 Signal output to Staefa input #1CB-A-5 Signal output to Staefa input #2CB-A-6 Signal output to Staefa input #3

CB-B-1 +15VDCCB-B-2 GroundCB-B-3 -15VDCCB-B-4 Gex CMDCB-B-5 Gex feedbackCB-B-6 Gex alarmCB-B-7 Gex minimum clapCB-B-8CB-B-9 Supply feedback; Phoenix TB-16-2CB-B-10 Offset control; Phoenix TB-16-3CB-B-11 Supply alarm; Phoenix TB-16-4CB-B-12 T-Stat output signal; Phoenix TB-12-1

CB-C-1 +15VDCCB-C-2 GroundCB-C-3 -15VDCCB-C-4 Mon CMDCB-C-5 Hood feedbackCB-C-6 Hood alarmCB-C-7 Hood user statusCB-C-8 Hood sash position

CB-D-1 N/CCB-D-2 GroundCB-D-3 N/CCB-D-4 Mon CMDCB-D-5 Hood feedbackCB-D-6 Hood alarmCB-D-7 Hood user statusCB-D-8 Hood sash position

PSIM Slave VersionInput/Output Terminal Convectors (IDC.1)

CB-A-1CB-A-2CB-A-3 Signal output to Staefa input #0CB-A-4 Signal output to Staefa input #1CB-A-5 Signal output to Staefa input #2CB-A-6 Signal output to Staefa input #3

CB-B-1 +15VDCCB-B-2 GroundCB-B-3 -15VDCCB-B-4 Mon #3 CMDCB-B-5 Hood #3 feedbackCB-B-6 Hood #3 alarmCB-B-7 Hood #3 user statusCB-B-8 Hood #3 sash positionCB-B-9 Hood #4 feedbackCB-B-10 Hood #4 alarmCB-B-11 Hood #4 user statusCB-B-12 Hood #4 sash position

CB-C-1 +15VDCCB-C-2 GroundCB-C-3 -15VDCCB-C-4 Mon #1 CMDCB-C-5 Hood #1 feedbackCB-C-6 Hood #1 alarmCB-C-7 Hood #1 user statusCB-C-8 Hood #1 sash position

CB-D-1 N/CCB-D-2 GroundCB-D-3 N/CCB-D-4 Mon #2 CMDCB-D-5 Hood #2 feedbackCB-D-6 Hood #2 alarmCB-D-7 Hood #2 user statusCB-D-8 Hood #2 sash position

TEST POINT TERMINAL CONNECTION IDC-.156

TP-1 T-stat override signal (TOS)TP-2 +15VCDTP-3 GroundTP-4 -15VDCTP-5 Set-up voltage inputTP-6 Input #0 voltage divider levelTP-7 Input #1 voltage divider levelTP-8 Input #2 voltage divider levelTP-9 Input #3 voltage divider levelTP-10 Input #4 voltage divider levelTP-11 Input #5 voltage divider levelTP-12 Input #6 voltage divider levelTP-13 Input #7 voltage divider level



PSIM MOUNTING TO SM2 BOARD



HOW TO GET STARTED

This section has been created to assist in determining what PSIM boards and cables are needed to interface betweenthe Phoenix Control’s MAC CARD or PANEL, and the Staefa Control’s SMART II boards. This section utilizes thePhoenix Room Schedule sheet, PSIM Selection and Configuration guide, PSIM Planning Chart, and the list of PointsRequired to be Monitored.

The PSIM interface board has been designed to serve three functions:

1) Provide a means of scaling the various Phoenix Control signals (down to a level or back up) to a levelthat a Staefa SMART II inputs can utilize with maximum resolution.

2) Provide a means of converting the Staefa Control’s phase-cut signal (to a scaled 0 to 10V DC signal)to match the Phoenix Control’s supply valve cfm/volt for Cooling override control.

3) Provide a means of converting the Staefa Control’s DO to a scaled 0 to 10V DC signal to match thePhoenix Control’s supply valve cfm/volt for Heating override control. (HOC Option)

In most lab situations the Staefa SMART II DDC controller should be setup for Temperature Override andAnticipatory Control. Anticipatory control uses all three control loops of the DDC controller and monitors the roomtemperature (SM2 input #5), discharge air temperature (SM2 input #0), and Phoenix Controls supply valve cfm (SM2input #6). As the fume hoods open and close, this increases and decreases the supply cfm’s. By monitoring thesupply signal and adjusting the discharge air temperature accordingly we anticipate the heating requirement, and ableto maintain room temperature. Thus able to minimize the temperature swings that occur due to the lag time of thetemperature sensor.

The minimum input points for Temperature Override and Anticipatory control are:

S Supply discharge air temperature (wires directly to the Smart II base input #0)

S Room temperature (wires directly to the Smart II base input #5)

S Supply valve cfm’s (feedback signal) (wires to the PSIM board CB-B-9, Smart II input #6)

The other Smart II inputs are used for monitoring additional Phoenix Control signals. These are based on the numberof points required by spec to be monitored. The following are a few examples:

S Gex Feedback signal (wires to the PSIM board CB-B-5, Smart II input #4)

S Total Exhaust Feedback signal (optional) (wires to the PSIM board CB-B-10, see note 1)

S Fume Hood Feedback signal (wires to the PSIM board CB-C-5, see note 1)

S Fume Hood Alarm signal (wires to the PSIM board CB-C-6, see note 1)

The minimum output points for Temperature Override and Anticipatory control are:

S Heating coil valve (wires directly to the Smart II base PO #6)

S Cooling Override control (wires from the PSIM board CB-B-12, Smart II PO #7)

NOTE 1: see PSIM - Selection & Configuration Guide for Smart II input designation.



To determine what type and how many Staefa Smart II controller cards and PSIM boards are needed for a given labsituation, you will need to locate the following items:

1) Confirming Room Schedule from Phoenix Controls

2) PSIM - Selection & Configuration Guide

3) PSIM - Planning Chart



4) List of Points required to be monitored in each lab (Found in Project Specs). The following are sometypical points that are frequently monitored:

-Supply & Gex Feedback signals (1 each) -Supply & Gex Alarm Signals (optional)-Total Exhaust Feedback signal -Room Offset Value (optional)-Fume Hood Feedback signal (1 each hood) -Fume Hood Alarm signal (1 each hood)-Fume Hood Status signal (1 each hood) -Fume Hood Sash Position (1 ea. hood, optional)

Now that you have located these items, it’s time to explain how to fill out the PSIM Planning Chart (you must firstmake several copies of the PSIM Planning Chart, at least one for each lab) and determine what PSIM boards areneeded. The information for the PSIM chart comes from the Phoenix Room Schedule and the PSIM Selection &Configuration Guide. We will be using as examples Phoenix application #9A for one hood configuration andapplication #16 for multiple hood configurations. (See information provided.) The PSIM Planning Chart is brokendown into ten sections (see item 3 of previous page). They are as follows:

1) Project information: Project ID #, Room #, and MAC type. This information is found on the PhoenixRoom Schedule Sheet.

2) Staefa information: Smart II type, Address #, and Trunk #. The Smart II type is determined by the typeof lab your working with. The address and trunk information can be added later when trunk layout iscomplete.

3) PSIM information: Serial Number and Configuration or type. The PSIM configuration is determined bythe selections you make from the PSIM Selection & Configuration Chart.

4) Phoenix Room Schedule information: The first seven columns of the PSIM Planning Chart are forPhoenix valve information. This information is located in the first nine columns of the Room ScheduleSheet. The columns are titled the same for easy transfer. (Supply, Gex, & Hood exhaust valves).

5) Staefa Sensor information: The first two rows of information in this section are set aside for the Staefasensors needed for lab temperature control. These sensors have specific Smart II inputs they connectto. Discharge Air temperature sensor uses input #0 and utilizes the limit functions in loop #0. The Roomtemperature sensor (RS1000) uses input #5 with a custom temperature range of 62 to 82 F with a 4.64ko

ohm pull-up resistor. Both the input gain and pull-up resistor are jumper selectable on the PSIM card(Jp#1 custom range T-30 gain, Jp#4 pull-up resistor).

6) Phoenix Valve information: The next eight rows are used to list the Gex and Supply valve part numbers,tag numbers, min & max cfms, and scale factors. Also listed are any Fume Hood valves and theirinformation, note, that each line should be considered as a input of the Smart II DDC card. In example#9 the valve information line contains the valve Feedback values and a separate line is used for Alarmsignals, and likewise a separate line would be used for User Status and Sash Position signals.

7) Temperature Override Signal (TOS) information: This information is located under the Make-up AirControl Specs. in columns Ovr Min and Ovr Max of the Room Schedule Sheet on the MAC CARDinformation line. Note: When ordering the Phoenix valves with Temperature Override Signal, and XX/XXshould be placed in the “TSTAT MN/MAX” box and PSIM should be indicated in the COMMENT box.This lets Phoenix Controls know that you are using a scaled 0 to 10V DC signal, (CFM/VOLT). The TOSoutput has two scaleable ranges. The “H” or high (full range) is scaleable between 0 to 3 volts at itsnarrowest span, and 0 to 10 volts at its widest span. The “L” or low range is scaleable between 0 to .9volts at its narrowest span, and 0 to 3.25 volts at its widest span. A narrower range may be obtained byreducing the Smart II’s P.O. maximum setting from the recommended setting of 90%, down to apercentage to achieve the desired output range. The TOS output is terminal #12 of CB-B terminal block.



8) Smart II input, Base, and Gain information: The input information comes from the PSIM Selection &Configuration Guide and is based on what points you selected and what terminal they are tied to (seeexamples #9 & #16). The base value should always be zero with the exception of the temperaturesensors. The gain values are based on the valve Maximum cfm values found on the room schedulesheet, divided by 255. The gain value for Alarm signals is 1.

9) PSIM set-up level & input option information: The Set-up Level comes from dividing the maximum cfm

value by the scale factor (CFM/VOLT). As for alarm signals, they are treated as a 0 to 10 volt signal.The PSIM Input Option # is derived from the PSIM Selection Guide based on the point you selected foreach Smart II input.

10) PSIM Wiring color code information: This selection is optional, but can be used to establish or maintain

the Phoenix wiring color code, it can also be useful when visually inspecting or trouble shootingconnection problems.

Before we begin filling out the PSIM planning chart(s), you will need to know the total number of points you’re goingto bring into the Smart II card(s) to be monitored (refer to item #4 of materials needed). Remember to include theroom and duct sensors in your total. Now take the total and divide it by 8 (eight) if you are planning to use all SM2DDC 8620's controllers. This gives the total SMART II cards needed for the lab. Or you can use 1 SM2 DDC 8620for control and use SM2 FNC 8620 card’s to bring in the rest of the points. You would then subtract the first 8 (eight)points from the total (1 SM2 DDC card) and then divide the remaining points by 7 (seven), for a total SM2 FNC cardsneeded. Add the two together will give you a total SMART II count. Now with this information you’re ready to selectwhat points, how many, and where you will bring them into the PSIM board and Staefa controller. This isaccomplished by using the PSIM Selection & Configuration Guide. The guide is divided into 3 groups of controllers:Master with T.O.S. (Temp. Overrive Signal), Sub-Master with T.O.S., and Slave or status inputs only. Under eachof these categories are several configurations of the various Phoenix points, Smart II types, Smart II inputs, andPSIM configuration information. The Selection & Configuration Guide is just that, A GUIDE, to give you variouschoices, or to help you customize your inputs. The only thing to remember is that each smart input can only beconnected to the CB terminal point as indicated by the Option Selection Jumper (OSJ#). Now you are ready to start filling in the PSIM Planning Chart. First fill sections 1, 2, & 3 with the Project information,Staefa information, and type of PSIM board you are going to use (refer to Examples #9a and #16). Sections 4, 5,& 6 we will combine and fill in at the same time. You should notice that the first Planning chart already has theStaefa sensor information fill in for you. This is because in the PSIM Master configuration with Anticipatory andTemp. override control, these inputs are used and have fixed inputs. If you use an Office supply as in Example #16you will need to add the room sensor information to the second PSIM Planning Chart. Now lets find the Master configuration that best fits your application on the Selection and Configuration Guide. ForExample #9a we have chosen the forth column from the left, Supply/Gex/Hood with Feedback and Alarm Signals.Now as you look down that column, there are “X’s” in specific rows. These indicate the Smart II type, cables needed,the Smart II input in relation to the Option selection jumper and the Phoenix point brought in on that terminalconnection. Now based on that information begin filling in section #6 of the PSIM planning chart. Remember thateach line is considered to be a SMART II input. The first row down is SM2 Type and the letter in the forth column over is a “D”, indicating that the SMART II type isa DDC 8620. The next section down is Cables, an “X” in this section indicates the cables needed for a standardhook-up, and if an “*” is used it’s a non-standard hook-up. There are two columns left in each of the three mainsections so you can customize the cables and inputs to fit your applications as needed. The next 8 (eight) sectionsdown are SMART II inputs and the options available for that input. There will only be one “X” in each input section.In input #0 the “X” indicates that JP#0 is open and the Option Selection Jumper #0 (OSJ#0) has No Selection (N/S)made. This input is used for Staefa’s Duct Sensor. If this input were being used on a PSIM Slave board with a SM2DDC, the JP#0 would be closed connecting the output of the op-amp to input #0, and the OSJ#0 would have selectedone of the other options. In input #5 the “X” indicates that OSJ#5 has No Selection made, this is because input #5is use for Room Sensor. Other jumpers now come into play, JP #1, 2, 3, 4. The JP#1 jumper selects the narrowrange gain for the T-30 sensor. The JP#2 selects at 2:1 gain for a standard Phoenix signal. The JP#3 jumperconnects the output of the Level pot (VR6) to the SMART II input, and JP#4 Connects a 4.64k%%133 pull-up resistorto the SMART II input.



Now as you are filling out section #6 with Phoenix information, you can also fill out portions of section #8, the SM2input selection and in section #9, the PSIM input OSJ#. The SMART II base values will be 0 (zero) with theexception of the sensor inputs #0 & #5. The SMART II gains for sensor inputs are: (T divided by 256) #0 = 0.2422,and #5 = 0.0781. The other inputs will either be: MAX CFM divided by 255, for feedback signals, or 1, for alarmsignals. This information will be needed when programming the SMART II card. The SET-UP LEVEL in Section #9can also be calculated and filled in at this time. The Set-Up Level is used when setting up the PSIM board on thetest bench with the PSIM-SSU (Signal Simulator Unit) prior to installation. By pre-setting all the signal level pots andT.O.S. zero and span pots before installation you can save time and the hassles of working in the ceilings over yourhead trying to make adjustments from the Factory settings. (See PSIM field calibration for more information).

The last row of information in the Planning Chart is section #7 the Temp. Override signal. This information comesfrom the same line as the MAC information on the Room Schedule sheet under columns OVR/min & OVR/max. TheOverride signal has the same scale factor as the Supply valve. Transfer this information and calculate both the minand max voltage for the set-up level. These voltages will be needed when setting the T.O.S. output. Note: Thissection is only used with PSIM Master or Sub-Master configurations.

NOTE: You should make at least one copy of the PSIM Planning Chart (reverse side) for each lab with controls.









PHOENIX/STAEFA SMART II INTERFACEVAV LAB LAYOUT AND CONTROL DESIGN THEORY

Most VAV laboratory fume hood systems will fall into three categories.

A. INTERIOR LABS WHICH ARE LOAD DRIVEN: i.e., there is a higher space thermal cooling load than thereis hood make-up air load. Reheat coils in labs that are load driven should be sized to only handle the make-up air for the space when the hoods are at maximum CFM (hood valves open and the general exhaustvalves at minimum flow).

B. INTERIOR LABS WHICH ARE MAKE-UP AIR DRIVEN: i.e., a higher make-up air requirement for thenumber of fume hoods contained in the zone, than what the space cooling requirement is. The reheat coilin these spaces will typically be capable of heating the full CFM delivered to the space up to 75 .o

Reheat coils in interior zone laboratories that are make-up air drive exhibit oversized characteristics when make-upair requirements are 50% or less of the total CFM capability of the supply air valves. This, in turn, causes dischargeair temperatures to be excessive on the VAV boxes, thus causing stratification and temperature swings.

The other classification is:

C. PERIMETER LABS WHICH ARE LOAD DRIVEN: i.e., the VAV box also provides heat to offset the thermalloss through the walls and building envelope, as well as the infiltration through the structure since most labsare kept negative with respect to surrounding areas. In this case, if the VAV valve and reheat coil in thespace is load driven (heating and cooling), it may end up having slightly higher discharge air temperaturerequirements than labs which are make-up air driven.

The following scenario happens when the room is at thermal equilibrium, with the fume hood sashes closed and thespace is in deadband calling for minimum cooling. When the hood sash is raised, the make-up air delivery increasesdramatically in the space. The room sensor having a 5 to 7 minute time constant does not proceed to add additionalheat to the space until the room temperature has dropped in the space some 3 degrees. The room occupants thenassociate opening the fume hood sashes with cold drafts. This consistently happens at VAV lab installation.

With the sash left open, over time the reheat valve proceeds to open and the room achieves thermal equilibrium.When the occupants close the sash, the control valve stays at the same position and the make-up air decreases.Consequently, the discharge temperature from the reheat coil rises dramatically and the space suddenly overheats.These temperature swings can be anywhere between 2 and 5 degrees with extreme temperature stratification of upto 10 degrees differential between the floor and the ceiling of the laboratory. This phenomenon occurs whether thereis one hood or multiple hoods in the same laboratory.

The same phenomenon is observed in perimeter labs as the sashes are raised or lowered, resulting in radical swingsin space temperature. With the general exhaust grills located in the ceiling in most laboratories, the stratification inmany instances can be excessive. In the perimeter rooms with the occupants seated near exterior glazing, thestratification causes the cold feet syndrome because of the apparent oversized reheat coil during partial flows.

The following solutions in the Atkinson Electronics, Staefa/Phoenix Interface Board and set-up of the Smart IIController resolve these problems. Loop 2 of the DDC controller monitors the zone temperature and provides anoutput to the Phoenix MAC card via PO #7 and the Atkinson Electronics Interface Card. The interface card sendsa 0 to 10 volt signal representing the call for cooling. Loop 1 then monitors the flow on the supply air against itssetpoint to determine whether reheat is needed for make-up air condition or a space temperature condition.

When the sash is raised when the zone is at equilibrium and the supply air valve is open to some CFM, if the sashopening exceeds the present supply air requirements, Loop 1 then notes that the supply air volume is greater thanthe valve as calculated by zone temperature control Loop 2. If the CFM is greater, then it, in turn, resets Loop 0 tobegin to add heat because the difference in the supply flow will have to be reheated based on the original thermalload before the sash was opened.



The appropriate Proportional Bands settings and offsets require to set up the controller properly to preventsimultaneous heating and cooling are documented in the Smart II DDC Set-up Procedures. Loop 0 then monitorsthe discharge air temperature of the reheat coil and receives its setpoint from Loop 1. The discharge air temperaturesetpoint of Loop 0 is reset between the minimum setpoint low limit and maximum setpoint high limit.

With interior load driven or make-up air driven zones, this setpoint should be set up as follows: The loop low limitshould be the design supply air temperature minus half the proportional band setting of Loop 0 (typically 10 degreesproportional band). The loop high limit setting should be no more than the desired zone temperature setting of Loop2. Where the reheat coils are also sized to handle perimeter heating losses, and infiltration, the high limittemperature setting will need to be raised to the design engineer’s supply air temperature at the heating CFM.

The CFM delivery in the typical laboratory can be anywhere from 2 to as many as 10 CFM per square foot, whichmay be determined by typical make-up air requirements and not necessarily the cooling load requirements of thespace. These higher flow rates coupled with the thermal lag of the room sensor of some 5 to 7 minutes as comparedto a duct sensor of around 30 seconds introduce additional lab control difficulties. The sensor lag problem isexacerbated when the resolution of the zone temperature sensor is 4 counts per degree.

For this reason, the interface card uses universal input #5 with a custom ranging to provide approximately 13 countsper degree of the zone temperature resolution.

This dramatically improves the response of the DDC card/sensor combination and increases stability in the labenvironment. Discharge temperature is then monitored by input 0 which provides 4 counts per degree resolution forthis discharge temperature loop which is being reset by the zone temperature at 13 counts per degree, providingexceptional control. Inputs from the Phoenix system, particularly the make-up air flow, should be scaled such thatthe total make-up air is equal to 255 counts to prevent degradation of controllability due to the 8 bit A/D converter.

With airflows changing by 100% under 1 second, the use of the Staefa magnetic chart valve with 1 secondpositioning time is mandatory for successful control.



Smart II DDC Set-up Procedure for Lab-Anticipatory Control

Step 1 Enter all Smart II input bases, gains, and units per PSIM planning chart

Step 2 Calculate cooling percentage of total make-up air for lab(Max Temp Override Value/Total Make-up Air = TOS%)

Step 3 Calculate Proportional Ban value for Loop #1 based on TOS%. Band select should be 100% of total make-up air.

TOS% PROPORTIONAL BAND LOOP #0 OFFSETVALUE VALUE

MAKE-UP DRIVEN 10-20% 25% of total make-up air +10.17

20-40% 30% of total make-up air +5.086

40-60% 32% of total make-up air 0

60-80% 35% of total make-up air -5.086

LOAD DRIVEN 80-100% 45% of total make-up air -10.17

Step 4 Loop #2 set-up. Start #49 and work back to 40.

#49 Loop 2 Direction Direct#48 Loop 2 Input Type Input #5#47 Loop 2 Setpoint Type Host 73.01 Fo

#46 Loop 2 Int Rate Approx. 50 sec.#44 Loop 2 Band Select 1.001-19.92o

#45 Loop 2 Prop. Band 5.383o

#43 Loop 2 Auto/Manual Automatic#42-40 Status Values

Step 5 Loop #1 set-up. Start at #39 and work back to 30.

#39 Loop 1 Direction Direct#38 Loop 1 Input Type Input #6#37 Loop 1 Setpoint Type Loop #2 +0.0 offset#36 Loop 1 Int Rate Inactive#34 Loop 1 Band Select xxx - max cfm value#35 Loop 1 Prop. Band Value Cal in Step #3#33 Loop 1 Auto/Manual Automatic#32-30 Status Values

Step 6 Loop #0 set-up. Start at 29 and work back to 20.

#29 Loop 0 Direction Reverse#28 Loop 0 Input Type Input #0#27 Loop 0 Setpoint Type Loop #1 offset value Step #3#26 Loop 0 Int Rate Inactive#24 Loop 0 Band Select 3.104-61.76#25 Loop 0 Prop. Band 10.12#23 Loop 0 Auto/Manual Automatic#22-20 Status Values



Step 7 Set-up prop outputs.

#90 PO6 Loop Assignment 0#91 PO6 Start % 0%#92 PO6 Stop % 100%#93 PO6 Min Voltage 20%#94 PO6 Max Voltage 90%#95 PO7 Loop Assignment 2#96 PO7 Start % 50%#97 PO7 Stop % 100%#98 PO7 Min Voltage 10%#99 PO7 Max Voltage 90%

Step 8 Set PO6,7 action to direct linear.

Step 9 Set Loop 0 Limits in configuration section.

B7 Loop 0 Limit EnableB8 Loop 0 Low Limit 45o

B9 Loop 0 High Limit 85o

NOTE: When verifying control loops in 100% call for heat, Loop 0 setpoint will be the high limit value (B9). Ifusing an SM-2 service tool, the setpoint will appear to have rolled over and will display the low limitvalue. This is the TOOL, NOT the SM-2 DDC Card. The PO output will remain at 100% call for heat.



NOTES:

1. Flow feedback, room offset, and thermal demand/min. ventilation points are scaled at specific CFM/voltvalues; i.e., 200CFM/volt, 500CFM/volt, 1250CFM/volt.

2. Sash position is an unscaled point relative to sash opening. Actual percent opening is field determined;i.e., 2 volts equals sash closed and 6 volts equals sash wide open. >10VDC signals an alarm condition.

3. Flow alarms are represented by a three state voltage. 0 volts - normal, 5 VDC jammed valve, >10DClow pressure.

4. The fume hood “user status”, and “occupied/unoccupied setback control” points are an “OR” typecondition. Either Phoenix will be controlling the occupied/unoccupied status of the fume hood, and theDDC system will monitor a two-state high voltage for status; i.e., 0 volt - unoccupied, >10 volt-occupied. OR, the DDC system will set back the hoods from occupied to unoccupied, or vice versa, via a contactclosure - digital output, or 0V normal - >10 setback analog voltage.

The occupied mode will maintain the fume hood face velocity within the typical realm of 80 to 125FPM. While the unoccupied mode will reset the hood to some locally adjustable lower face velocity as apercentage of the occupied face velocity; i.e., 100FPM occupied, 60FPM unoccupied.

5. The Phoenix fume hood monitor contains an emergency exhaust push button to drive the fume hoodexhaust valve open, irrespective of sash position, during and emergency condition. During the normalmode, the fume hood exhaust valve is commanded via a scaled 0-10VDC signal. Under and emergencyexhaust condition, the command signal becomes saturated, >10.5 volts. Therefore, the 0-10V commandsignal could be monitored for diagnostics, while the >10.5 volt portion would have to be monitored todetermine an emergency exhaust condition.

6. A laboratory emergency vent or purge mode can be initiated from the DDC controller, or a push-buttonwithin the lab from the DDC controller 0V-normal, 5B purge (supply closed/exhaust open), 10V vent(supply open/exhaust open). Or from a push-button that inputs a contact closure to the Phoenixcontroller that is “jumpered” to exclusively perform “vent” or “purge”.

Documents

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