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INSTALLATION & OPERATINGINSTRUCTIONS FOR

COMBINATION HEATING AND COOLING ROOFTOPNOMINAL 7-!-h AND 10 TON

MODEL SERIES“(-)RGB/(-)RGC” - GAS HEATING & ELECTRIC COOLING

(EQUIPPED WITH ELECTRONIC SPARK IGNITION)

“(-)REB/(-)REC” - ELECTRIC HEATING & ELECTRIC COOLING“(-)SCB/(-)SCC” - ELECTRIC COOLING ONLY

PAG E

MODEL lDENTlFlCATlONS. . . . . . . . . .

2INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . ..ZCHECKING PRODUCT RECEIVED . . . . . . . . . . . . . . . . . . . . .2PHYSICAL DATA TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3DESCRIPTION GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4DESCRIPTION CABINET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DESCRIPTION GAS HEATING . . . . . . . . . . . . . . . . . . . . . . . . 5DESCRIPTION ELECTRIC HEATING . . . . . . . . . . . . . . . . . . .5DESCRIPTION COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DESCRIPTION BLOWER MOTORS . . . . . . . . . . . . . . . . . . . . .6AIR FLOW PERFORMANCE .......................... .7COOLING CAPACITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8LOCATING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8DIMENSIONAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8RIGGING AND UNIT PLACEMENT . . . . . . . . . . . . . . . . . . . . .9INSTALLATION - DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . .9INSTALLATION - GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . .I0INSTALLATION - DRAIN PIPING . . . . . . . . . . . . . . . . . . . . . .11ELECTRICAL DATA TABLE .I2INSTALLATION -WIRING .::::::::::::::::::::::::..13START UP - CHECKS - ADJUSTMENTS .............. .I5HEATING SYSTEM GAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15HEATING SYSTEM ELECTRIC . . . . . . . . . . . . . . . . . . . . . . . .17COOLING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I 7CHARGING CHARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18OPERATING SEQUENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20COMPONENT LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . .21TYPICAL WIRING SCHEMATIC . . . . . . . . . . . . . . . . . . . . . . .22ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..2 3ECONOMIZER OPERATING SEQUENCE . . . . . . . . . . . . . .23RELIEF DAMPER ACCESSORY . . . . . . . . . . . . . . . . . . . . . . .24ROOF CURB ACCESSORY . . . . . . . . . . . . . . . . . . . . . . . . . . .25

UNIT MODEL IDENTIFICATION7% & 10 TON ROOFTOP

HEATING AND COOLING

3c0n0p -Type HeatingRG GasRE ElectricSC cool only

Sews NumberC Standard ModelB High Efkxncy

Gas Heat265 265.000 BTUH (C Series)266 265.ooO BTUH (B Series)

Electw HeatTotal K.W.: 020 213 K.W

040 40 K.W.060 6 0 K . W

Ncmm Tons Ccofng Capacity-075 75Tms- l M 100 Tons

Electrical CharacteristicsC 3:6&2@3/230D 360460

The information contained in this manual has been prepared toassist in the proper installation, operation and maintenance of ttieRooftop system. Improper installations can result in unsatisfac-tory operation or dangerous conditions, and are not covered by ’the unit warranty.

Read this manual and any instructions packaged with separateequipment required to make up the system prior to inStallatiOn.Give this manual to the owner and explain its provisions. Theowner should retain this manual for future reference.

CHECKING PRODUCT RECEIVED

Upon receiving unit, inspect it for any damage from shipment.Claims for damage, either shipping or concealed, should be filedimmediately with the shipping company.

Check unit model number, heating sizes, electrical characteris-tics and accessories to determine if they are correct.

*Gas units are A.G.A. design certified. Electric HEAT and COOLINGONLY are U.L. listed.

2

PIPE CAPACITY TABLEMaximum Capacity of Pipe in Cubic Feet of Gas Per Hour

(Based upon a Pressure Drop of 0.3 Inch Water Column and 0.6 Specific Gravity Gas)

l Rooftop model installations must conform with localbuilding codes or in absence of local codes, with the NationalFuel Gas Code ANSIZ 223.1-1980.

l Size gas supply piping for 0.3 inch w.c., maximum pressuredrop. Do not use supply pipe smaller than unit gas pipe con-nection. See Pipe Capacity and Gravity Factor Tables forrecommended pipe size for natural gas.

l Pitch pipe l/s inch per 15 foot length. Pitch all horizontalruns upward to risers and from risers upward to meter.

l After horizontal gas pipe runs, provide dirt and moisturepockets upstream of unit, below the unit, and at the base ofall vertical pipe risers. Refer to Suggested Gas Piping Detail.

l Install gas shutoff valves external to the unit if required bycodes. (An external valve is recommended.)

l When connecting gas piping to unit piping, a ground jointmust be installed between unit gas pipe nipple and gas pip-ing by installer.

l When connecting gas piping to unit piping, hold unit pipingwith pipe wrench to prevent unit piping and gas valve fromturning.

l Piping should be tight, and compounds used on threadedjoints of gas piping must be gas-resistant to action of Ii-quified petroleum gases.

l Purge air from line after piping is complete. Pressurizesystem and check for leaks with soap and water solution. Donot use an open flame for checking gas leaks. Caution: Donot exceed I/Z PSI (14” W.C.) on gas valve when pressurizingsystem to check for leaks.

. It is advisable to insulate gas lines if extensive runs are ex-posed to outdoor temperatures.

l A ‘/B inch N.P.T. plug tapping, accessible for test gauge con-nection, must be installed upstream of the gas supply to thefurnace.

l The furnace must be isolated from the gas supply pipingsystem by closing its individual manual shut-off valve duringany pressure testing of the gas supply piping system at testpressure equal to or less than % PSIG.

l The furnace and its individual shut-off valve must bedisconnected from the gas supply piping system during anypressure testing of that system at test pressure in excess of% PSIG.

10

l-+;gth

Get102030405060708090

100125150175200

Nominal Iron I

H %132 27892 19073 15263 13056 11550 10546 9643 9040 8438 7934 7231 6428 5926 55

Is Size, inches

1 Y4 I?41,050 1,600730 1,100590 a90500 760440 670400 610370 560350 530320 490305 460275 410250 380225 350210 320

GRAVITY FACTOR TABLEMultipliers to be used only wrth Tables

when Applying the Gravity Factor

Spdfk‘Gravity

.35

.40

.4550.55.60.65.70.75.80.85.90

Multiplier1.311.231.161.101.041.00.96.93.90.87.83.a2 :

Speclflc zGravity Multiplier1.00 .7a1.10 .741.20 .711.30 .681.40 .661.50 .631.60 .611.70 .591.80 .5a1.90 .562.00 .552.10 .54

2,1001,6501,4501,2701,1501,050990930870780710650610

SUGGESTED GAS PIPING

‘b” N.P T. PLUG TAPPINGACCESSIBLE FDA TEST GAUGECONNECTION

UNIT GAS

/--

FROM GASCONNECTION METER

‘/a” N.P.T. PLUGTAPPING. ACCESSIBLEFOR TEST GAUGE

FROMGAS METER

L UNIT GAS SUPPLYCONNECTION

ROOF INSTALLAllON GROUND LEVELINSTALLAllON

T -RGBI-RGC IUnit Model

Number

-SCB/-SCC

-ooO-

-075-c -100-c -075-o -106

Power Supply Voltage 2081230 460Power Supply Hertz 60 60Power Supply Phase 3 3 ._Total F.L.A.Total L.R.A. T

I -285- 1 -020- ( -040. I-060- 1 -020. 1 -040- I-060-

2081230 460 208123060 60 603 3 3

1 I I I I

: -075-D -100-D -076-C -075-C -075-C -100-C -100-C -100-l

460603

50143

J-

60 25173 71

2 223 10

135 54

108143

2:108

3

156 60 108191 173 173

2 2 220 23 23

108 135 135

3 3 3

-156191-

223

135-

3

30 5471 71

2 210 1054 54

3 3

2.2 22 2.2 22 22 11 115.6 56 5.6 56 5.6 29 29

6.5 6.520.6 20 6

6520.6

2205.4

65ZO.6

65!O 6-

22054--

32 3210 3 10 3

2 210 1028 28

22.05.4

22054

2205.4

---

-

-

---

---

40 60 20 40187 187 187 187253 253 253 253150 200 80 150135 195 75 135

Compressor No./UnrtCompressor R.L.A. Ea. (3 PH.)Compressor L.R.A. Ea. (3 PH )

?i108

Blower Motor No./Unit (See l Below)Blower Motor (l/d H.P.)

F.L.A. EachL.R.A. Each

Blower Motor (1 H.P.)F.L.A. EachL.R.A. Each

3 3 3

78 30 5496 85 85

2 2 210 11.5 11.554 66 66 i

3 3 3

66

3

I 2.25.6L6.5

20.6

3 3 3-l---l-2.2 1.1 1.15.6 2.9 2.9

2.2 22 1.15.6 5.6 2.9

30 6085 143

2 211.5 2066 108

3 3

1.1 2.229 56

3.2 6.5IO 3 20.6

2 210 2.02.8 5.4

1 -.45 -.62 -

- 20414 187506 25340 8034 75

1.1 1.129 2.9

3.2 3.2IO 3 10 3

2 210 - 1.028 28

1.129

1.12.9

6.5 6.5 3.2IO.6 ZO.6 IO.3

3.2 3.210.3 10.3

Fan Motor No./UmtFan Motor F.L.A. Ea. (1 PH.)Fan Motor L R.A. Ea.

22.05.4

---

i

-1872537060

22054

2 220 1.05.4 28

2 210 1.02.8 2.0

Vent Motor No.!UnitVent Motor F.L.A. (1 PH.)Vent Motor L.R.A.

1 1 1.95 .95 45

1.22 1.22 62

---

- ---

---

---

Total Electrtc Heater K.WOperating Voltage (Mu.)Operating Voltage (Max.)Fuse Size Min. and MaxWirino Amoacitv ( 68 1 30 [ 34

Wire Size Min. AiG.I .

. ‘/

-la7253

;oo

- -187 414253 50680 3568 30

60187253200195-

20 40 60 20 40 60414 414 414 414 414 414506 506 506 506 506 50640 70 100 40 70 10038 68 98 38 68 98

M&i&i Supply Wire Length 11 .-q-~&i-, *, 1 ” _r”i.’

,.~ ,.+ -2_ill .:: li_‘“,:<

68 Copper #6 Aluminum 75 60 75 60 75 60#6 Copper #4 Alumrnum 117 100 117 100 117 100#4 Copper #3 Aluminum 93 76 185 155 93 76 185 155 185 185 155 155#3 Copper #2 Alumrnum 113 94 225 188 113 94 225 188 113 94 225 225 188 188#2 Copper Xl!0 Aluminum 149 124 275 245 149 124 275 245 149 124 275 275 275 245 245 245#l/O Copper X2/0 Aluminum 220 184 295 220 184 295 220 220 184 184 295 295 295#2/O Copper #3/O Aluminum 280 229 280 229 280 280 229 229#3/O Copper #250 Alumrnum 280 280 320 320 320 280 280 280

NOTE: 1. Above data subject to change - check data plate on unit.2. Comply with N.E.C. and local codes.3. On units equipped with accessoryconvenienceservice outlet(ll5 Volt)wiring

ampacity, and wire size may increase, check unit data plate.4. Total L.R.A. based on normal start up of condenser fans, evaporator fans, andone compressor. For L.R.A. with both compressors starting at add

once com-pressor L.R.A. to total L.R.A. listed.

l B Series-075 - (2)'/4 H.P. 8 (1) 1 H.P.-100 -(2) '/4 H.P. & (1)l H.P.

l C Series-075 - ‘/4(1) H.P. 8 1 H.P.(2)

--100 ‘/4(1) H.P. 8 1 H.P.(2)

B Series-075 - 7.5 E.E.R.-100 - 7.5 E.E.R.

C Series-075 - 7.0 E.E.R.

--100 7.0 E.E.R.(u

NOTE: Field wiring must comply with the National ElectricCode and any local ordinance that may apply.

ELECTRICAL POWER

It is important that proper electrical power is available for theunit. Voltage must not vary more than 1 O%of that stamped onthe rating plate. (See Electrical Data Table for minimum andmaximum voltage.) Interphase voltage variation on three-phase units must not be more than 3%. Contact local powercompany for correction of improper voltage or phase unbal-ance.

ELECTRICAL POWER SOURCE

Power is supplied to the unit from a field supplied fuseddisconnect switch installed by contractor within sight of theequipment. Wiring is connected to the factory suppliedpower terminal block in the unit.

DISCONNECT SWITCH - OPTIONAL

A disconnect switch of adequate size to handle the unitstarting current is provided and it should be unnecessary tofield install a disconnect switch within sight of the unit.NOTE: Unit is furnished standard with a power block withpower supplied to unit from fused disconnect within sight ofunit.

FUSING

The branch circuit feeding the unit must be fused asshown inElectrical Data Table. Use only fuse size shown.

POWER WIRING

Power wiring should be run in grounded rain-tight conduit.See Electrical Data Table for wire ampacity and proper wiresize.

WIRE ROUTING

Wiring is routed to right hand center post on condenser airinlet side of unit (see photo on page 13). Open both righthand and center louvered condenser doors. Remove 3screws on each outer side of post (as indicated in photo) andremove backof field wiring box attached to post. Run powerwiring and conduit to knockout in condenser post marked“power wiring”. Follow connection diagram shown on boxcover (see Figure showing power wiring) and connect powerwiring to back of power terminal block or optional discon-nect switch on terminals marked Ll, L2 and L3. Tighten wiresecurely in wire lugs.

ALUMINUM WIRE

Power wiring lugs provided on disconnect switch are suita-ble for use with aluminum wire. To help guard against over-heating, the following procedure is recommended whenconnecting aluminum wire.

l Strip the wire of its insulation to the desired length withoutringing or nicking the wire.

l Wire brush the stripped portion of conductor thoroughly.

l Thoroughly coat stripped conductor with oxide inhibitingcompound. (Two recognized compounds are Penetrox “A”and Alnox “UG.” There may be others available which will doequally well.)

l Insert the conductor into the connector making certain allstrands are contained and tighten the connector screws sec-urely. This operation should result in the compound oozingOut from between the individual strands of the conductor. If14

this does not happen, this is an indication an insufficientquantity of compound was used.

l Wipe excess compound from area adjacent to connectionbecause some compounds contain metallic particles andcould reduce the dielectric strength of the insulating materi- ri:als employed. @

GROUNDING

l Warning: The unit must be electrically grounded, in ac-cordance with local codes or the National Electric CodeANSllNFPA No. 70-1981.

. A grounding lug is provided near the terminal strip for aground wire.

l Grounding may be accomplished by grounding the powerline conduit to the rooftop unit. Make sure the conduit nutlocking teeth have pierced the insulating paint film of thecondenser post.

CONTROL WIRING

l Low voltage control wiring should not be run in conduitwith power wiring, unless Class 1 wire of proper voltagerating is used. Route thermostat cable or equivalent singleleads of No. 18 Awg. colored wire from thermostat subbaseterminals thru 7/s” bushing marked low voltage on condenserpost to low voltage terminals in field wiring box. Make con-nections as shown on unit wiring diagram and in figureshowing control wiring. Use No. 16 Awg. wire for lengthsexceeding 50 feet.

l Do not short thermostat wires since this may blow fuse incontrol transformer.

THERMOSTAT

A two-stage heating/two-stage cooling thermostat withmatching switching sub-base may be ordered as an acces-sory. Thermostats are available in either automatic or manualchangeover. The thermostat should be mounted on an insidewall about five feet above the floor in a location where it Willnot be affected by the sun, or drafts from open doors or othersources. Install level and after installation check the ther-mostat calibration and recalibrate if necessary. See sectionon Adjustments for Thermostat Heat Anticipator Setting.

NIGHT SWITCH

If field supplied night switch is used, connect as shown forcontrol wiring connections. Remove factory-installedjumper across terminals “1” and “C”.

208 VOLT OPERATION

For 208 volt operation the primary taps on the unit Controltransformer(s) (CTl, CT2 and CT3) should be changed to the208 volt tap (See Unit Wiring Diagram).

WARNING

After completion of wiring check all electrical connections,including factory wiring within the unit, and make sure allconnections are tight, replace and secure all electrical boxcovers and access doors before leaving unit or turning onpower to circuit supplying unit.

<:d:c

HEATER SHUT-DOWN GAS VALVE WIRING DETAIL

Place system selector switch at “off” or place heating selec-tor lever at a setting below room temperature.

CHECKING THE FIRING RATE

l The actual gas input rate should beset as close as possibleto the design input marked on the rating plate and neverabove that figure.

l Before checking. the unit must be in high fire operation(wall thermostat heating selector switch set to its highestsetting) and all other appliances connected to the metermust be turned off.

l The gas input rate is checked by timing the rotation of thecubic foot dial of the gas meter. Then multiply the gas inputrate in cubic feet per hour by the heat content of the gas.

For Example:

3600 Sec.iHR.12.6 Sec..‘Cu. Ft. = 285 Cu. Ft./Hr

285 Cu. Ft.:‘Hr. x 1000 BTU/Cu. Ft. = 285,000(assumed local value) BTUH

Values within 10% of the above capacity, but not to exceedthe input rating, are considered acceptable.

CHECK THE HEATING AIR TEMPERATURE RISE

On gas unit check the inlet and outlet air temperatures afterunit has been running on heating for at least 15 minutes onhigh fire (thermostat set to highest heat setting). Air tempera-ture rise must be between 45OF and 75OF.

GAS VALVE

l Thegas valve (See Detail) opens and closes in response toa thermostat or limit control. This valve also functions as apressure regulator.

l Gas valve wiring detail is illustrated. When circuit is com-pleted between “WI” and “Cl” terminals, the valve opens thepilot gas line. Pilot flame energizes the first stage of heatingthrough the integral mercury vapor bulb and the unit oper-ates at present low fire position. When circuit is completedbetween “WZ” and “CZ”, valve will open to high fire position.

GAS VALVE DETAILREG ADJUSTMENT/

PILOT ADJUSTMENT

Z-STAGEHIGH LOW-OFF

THERMOSTAT , _VALVE

1----_ \

MAIN 2:ON-OFF c+

COIL czi23A gi

GAS FUEL TYPE

l Do not connect propane gas to units equipped for naturalgas or natural gas to units equipped for propane.

l NOTE: Units are certified for use with natural or propanegases only. Units are not certified for use with any other fuels.

MANIFOLD PRESSURE ADJUSTMENT

lo adjust manifold pressure on natural gas, refer to GasValve Detail and proceed as follows:

l Remove l/s” pipe plug from pressure tap connection ongas valve and install a pressure measuring device.

l Before checking, the unit must be in high fire operation(wall thermostat heating selector switch set to its highestsetting).

l Remove plastic cover covering regulator adjustmentscrew and turn adjustment screw clockwise to increasepressure or counterclockwise to decrease pressure.

l Final manifold pressure should not vary more than 0.3”W.C. from the specified 3.5” W.C. for natural gas.

l Once desired pressure setting is established, removepressure measuring device and replace l/a” pipe plug andplastic cover.

l Final manifold pressure should not vary more than 0.3“W.C. from the specified 9.7” W.C. for propane gas.

PRIMARY AIR ADJUSTMENT

The flame from the main burners should be observed. Itshould be a stable blue flame with an orange cone tip.

l To adjust for this flame, close primary air shutters until theflame turns yellow-white at the tips, then slowly open theshutter until the white and smoky appearance disappears.

l Normal primary air adjustment for natural gas is full openon the air shutters.

l Normal primary air adjustment for propane gas is 213closed on the air shutters.

PILOT FLAME ADJUSTMENT

A pilot flame that is too high may cause burners to cycle onpilot flame switch and a flame that is too low may causeburners to cycle or prevent burners to light.

l To adjust, remove pilot cap screw (See Gas Valve Detail) toincrease pilot flame turn adjustment screw counterclock-wise or clockwise to decrease pilot flame.

l After proper pilot flame has been obtained replace pilotadjustment cap screw.

MAIN LIMIT AND FAN SWITCH

Limit switch settings are 180°F for the “B” Series and 230°Ffor the “C” Series. Fan switch settings are 120°F for both“B” and “C” Series.

PILOT GAS CONNECTION

16

ROOM THERMOSTAT ADJUSTMENT

Thermostat heat anticipator should be set at .40 amps on thefirst stage and .45 on the second stage heating.

l NOTE: See section on “Operating Sequence” for a de-scription of heating operating sequence.

l Check to make sure all grilles and registers are open andall unit access doors are closed before start-up.

l Set wall thermostat to its lowest position and place the fanswitch in “Auto” or “On” Position.

l Reset the heating temperature lever on the room thermos-tat at a value above room temperature.

HEATING SHUT-DOWN

Place system selector switch at “off” or place heating selec-tor lever at a setting below room temperature.

CHECK HEATING AIR TEMPERATURE RISE

On electric heating models outlet air temperature must bebelow 2OOOF.

ROOM THERMOSTAT ADJUSTMENT

Thermostat heat anticipator should be set at .58 amps on thefirst stage and .35 amps on the second stage heating.

OUTDOOR THERMOSTAT ADJUSTMENT

Supplied on 60 KW electric heating units only. If provided, setoutdoor heating thermostat at desired outdoor air tempera-ture to energize 20 KW electric heat control!ed’by outdoorthermostat (25O F to 60° F adjustment).

Thermostat is located in main control box accessible tromthe center louvered condenser door. Turn adjusting screwcounterclockwise to decrease heater cut in temperature Orclockwise to increase heater cut in temperature.

l NOTE: See section on “Operating Sequence” for a de-scription of cooling operating sequence.

l Remove metal shipping brackets from under each com-pressor mounting feet (8 brackets).

l Check high and low side refrigerant service valves(Schrader Type) and make sure they are closed.

l Energize main power to unit - compressors for twelve(12) hours to allow crankcase to come up to temperature.

l Set system selector switch at “Cool” or “Auto” and adjustthermostat at a setting just below room temperature. No. 1compressor should start. After No. 1 compressor hasstarted, set cooling lever to its coldest position, compressorNo. 2 should start.

l Check condenser fans and indoor air blower to make surethey are running free and quiet.

l Check cooling effect at duct supply outlets. Is indoorblower speed (CFM-ESP) correct?

l Reset thermostat at a setting above room temperature.This will de-energize compressors.

COOLING SHUT DOWN

l Place system selector switch in “off” position or resetthermostat at a setting above room temperature.

l Do not de-energize main power disconnect except whenunit is to beserviced. Power is required to keepair condition-ing compressor crankcase warm and boil off refrigerant inthe oil.

MANUAL RESET CONTROLS

l The unit is equipped with high pressure controls on eachair conditioning system and overload protectors in each in-door blower motor. If it is necessary to reset a high pressurecontrol or motor, check for the cause of the overload.

l High pressure controls are located in the front section ofthe main electrical box. This box is accessible through thecenter louvered door on the condensing section.

l Slower motor reset buttons are located in the end of each 1H.P. blower motor. They are accessible through the top ac-cess panel on the filter end of the unit. l/4 H.P. motors haveautomatic reset.

LOSS OF REFRIGERANTChecking the charge after start-up - Each air conditioningsystem should be checked for proper charge after start-up.Connect an accurate pressure gauge to the liquid line andsuction line service ports in the condensing section. Purgelines and gauges, before tightening the connecting hoses.Attach an accurate thermometer to the suction line at thecompressor and insulate it to the line. A silver clip and mer-cury in glass thermometer is recommended for measuringsuction line temperature. Start thesystem and let it settle outfor about 30 minutes with all compressors running, thenmeasure suction pressure, suction l ine tem-perature and dry bulb temperature of the air entering thecondensing coil taken at about the center of the air louvers.Check to see if one or two condenser fans are operating anduse appropriate charge chart. On charge chart mark interse-ction of suction pressure and suction line temperature. Ifintersection is within -t 50 of outdoor temperature, the unitcharge is correct.

ADJUSTING CHARGEIf the data taken during “checking charge” is not withintolerance with that shown on the charge curve adjust asfollows:

OVERCHARGEIf a system is overcharged it will be indicated by intersectionof suction pressure and suction line temperature above out-door temperature line. If overcharged, purge refrigerant fromthe suction service port slowly until conditions agree withthose shown on the charge curve.

UNDERCHARGEIf the system is undercharged it will be indicated by intersec-tion of suction pressure and suction line temperature belowoutdoor temperature line. If undercharged connect a tank ofrefrigerant-22 to the suction line service port and purge linefrom tank of refrigerant before tightening the line at thevalve. With the system in operation open valve on refrigeranttank and charge slowly until conditions agree with thoseshown on the charge curve. Always add gas-not liquid. (Donot turn tank upside down.) Placing refrigerant tank in con-denser discharge air stream will speed up charging rate.After setting the charge, remove gauge and charging linesand replace service port caps.

17

NOTE: Do not operate unit to the left of the limit line oncharge chart. Operation to the left of the limit line indicateslow air flow and/or overcharged unit. If air flow cannot beincreased, adjust charge to bring mark to right of limit lineand down to outdoor temperature line.

LEAK TESTING

If a unit has lost all or part of its charge it has leaked outsomewhere and must be repaired and leak tested beforeevacuation and recharging. A Leak Detect0rG.E. Model H-10is excellent for finding small leaks. Leak test all refrigeranttubing. coils, compressors, and valves. Repairanyleakfoundbefore evacuation and charging.

EVACUATION

Systems must be evacuated only if all the refrigerant chargehas been lost. The evacuation of any system that has beenexposed to atmosphere or lost its charge is essential beforerecharging (check unit at service port for charge). Neverattempt to operate a system while it is under a vacuum. Use arefrigeration type vacuum pump capable of evacuation in the500 micron range. Connect the vacuum pump to a 3-wayservice man’s valve. Install an accurate pressure gauge thatwill read from a 30” vacuum to 400 PSIG. Connect the 3-wayvalve to the suction and discharge valve port. Evacuate to atleast 29.5” of vacuum. The triple evacuation method shouldbe used. This involves evacuating the system three times to a

vacuum of about 29.5”. After the first and second evacuation,new refrigerant should be used to break the vacuum, bringthe system down to approximately “0” PSIG each time. Afterthe third evacuation, the system is ready for charging.

CHARGING BY WEIGHT

If a system has lost all its refrigerant charge, the refrigerantcharge should be replaced by weight (check system chargeat service port). With the unit off follow the steps below: (DONOT OPERATE THE SYSTEM).

l If the charge has been lost it will be necessary to evacuatethe complete system. Leave system under vacuum (no gascharge).

l Connect a tank of refrigerant-22 to the liquid line serviceport and purge connecting line with refrigerant from tankbefore tightening line.

l With an accurate scale+ l/z oz. set refrigerant tank up so itsweight can be measured while in a position to charge liquid(unit must be off).

l Open valve on refrigerant tank and charge unit with exactweight shown on Physical Data Table or unit nameplate.When unit has been charged with correct amount turn tankoff and remove hose.

l After weighing in charge, check and adjust charge as de-scribed above.

18

-075 - COOLING SIZEBOTH CONDENSER FANS RUNNING

.,

.SUCTION UNE ,fbWfA~“Sf ‘I

40 so 60 70 80 90

-100 - COOLING SIZEBOTH CONDENSER FANS RUNNING

@

-075 - COOLING SIZEONECONDENSERFANRUNNING

I:

-100 - COOLING SlZEONE CONDENSER FAN RUNNING

SUCTION LINE TEMPERATURE S

40 50 60 70 80 90

SYMPTOM CAUSE CURE

High head pressure

Low head pressure

Low suction & hot compressor

Excessive sweating of compressor

a. Airflow to or from condenser restrictedor dim condenser

b. Faulty condenser fan or motorc. Overcharge of refrigerantd. Air in systema. Short of refrigerantb. Low evaporator air flowa. Short of refrigeranta. Low indoor airflow

b. Excess refrigerant

a. Remove obstructionif necessary clean condenser.

b. Replacec. Bleed charged. Evacuate and rechargea. Check for leak, add chargeb. Increase blower speed, check filtersa. Check for leak - add refrigeranta. Increase Speed of blower or reduce

restriction - replace air filterb. Slowly bleed off charge

COOLING

Power on and thermostat set at “Cool”, “Fan Auto” anddesired temperature.

l STAGE #l of cooling thermostat energizes outdoor fanand indoor air blower and #I compressor.

l STAGE #2of cooling thermostat operates #2compressor.

l INDOOR BLOWERS will operate on cooling and heating aswired and connected in field. See pages 6 and 7.

l CAPACITY CONTROL is provided by 2-stage thermostatwhich stages the compressors as the load changes.

l COMPRESSOR_ PROTECTION each compressor is pro-a---, tected by high pressure cpntrol, compressor internal ther-

ft. ;&’

mostat and overloads. Crankcase heaters provide protectionagainst liquid migration to the compressors and liquid slug-ging on start up.

l HEAD PRESSURE CONTROL -One condenser fan motoris cycled off by a thermostat when the outdoor air tempera-ture drops below 55OF.

HEATING - GAS

Power and gas on, thermostat set at “Heat,” “Fan Auto” anddesired temperature.

l STAGE#l of heating thermostat energizes thevent motor.Electronrc ignition circuit will ignite pilot. When pilot flame isproven, the #l Stage of the two stage main gas valve isenergized. Burners are now at low fire. After a time delay orwhen plenum temperature is reached the indoor blower isenergized.

l STAGE #2 of heating thermostat energrzes the#2 Stage ofthe main gas valve and the unit operates at full heatingcapacity.

l INDOOR AIR BLOWERS will operate on cooling and heat-ing as wired and connected in field. See pages 6 and 7.

l CAPACITY CONTROL is provided by two stage thermostat.Unit may cycle between partial and full capacity as Stage #2dictates. When Stage #l of the thermostat opens, the cen-trifugal switch on the vent motor opens and closes the maingas valve. Indoor arr blower motors are de-energized whenplenum temperature is satisfied.

‘\L

l PILOT AND IGNITION CONTROLS An electronic spark ig-I’ nitron pilot relight system is provided as standard. On a call

for heat from Stage #l of the indoor thermostat, the ventermotor begins operation. The electronic spark ignitor is thenenergized through a centrifugal switch in the venter motor.

The ignitor continues to spark until pilot ignition is estab-lished, or until power is disconnected from the unit. Estab-lishment of the pilot flame de-energizes the spark ignitoruntil the next call for heat.

l HEATING PROTECTION The heating system is protectedby an outlet air limit switch, two reverse air flow limitswitches, centrifugal switch on the vent motor and a pilotflame switch.

HEATING - ELECTRIC

Power on, thermostat set at “Heat,” “Fan Auto” and desiredtemperature.

l STAGE #I of heating thermostat energizes indoor blowersand first 20 KW of electric resistance heaters. On 60 KW units,40 KW is energized with #l Stage if outdoor temperature isbelow outdoor thermostat setting.

l STAGE #2 of heating thermostat energizes second 20 KWof electric heat if provided. (Stage #2 provided on 40 and 60KW units only.)

l OUTDOOR THERMOSTAT, if provided, controls 20 KW ofelectric resistance heaters on 60 KW units only. When out-door temperature drops to thermostat set point (field adjust-able from 25O to 6OOF.) an additional 20 KW is energized withthe #l Stage of the room heating thermostat. Heating ele-ments are connected so that the load on the three-phasepower supply is balanced.

l INDOOR AIR BLOWERS will operate on cooling and heat-ing as wired and connected in field. See pages 6 and 7.

l HEATING PROTECTION Each 6.63 KW electric heater ele-ment is protected by an automatic reset limit thermostat andheat limiters for primary and secondary overcurrent andthermal protection. Two reverse flow limit thermostats areprovided for back up protection in event of a blower failure.Each heater circuit it protected individually by 60 amp max-imum size fusing.

AUTOMATIC CHANGEOVER*

When system selector switch is set at “Auto”, unit will au-tomatically change from heating to cooling when the temp-erature of the conditioned space rises to the cooling leversetting. When the temperature of the conditioned space fallsto the heating lever setting, the unit will automaticallychange from cooling to heating.

The thermostat and unit are so connected that the coolingand heating systems will not operate simultaneously.’ Apphes only to systems with optional automatic changeover type thermostats.

19

L

AIR CIRCULATION

With power on and room thermostat set at “System Off” and“Fan/On”. indoor air blower operates continuously on pre-determined cooling speed for air circulation. When controlsare set at “Heat” or “Cool” and “Fan-On”, heating or coolingis provided as required while indoor blower motor operatescontinuously at cooling connected speed.

FRESH AIR DAMPER

Unit is equipped with a manually operated outside airdamper which will permit up to 25% outdoor air to be mixedwith return air. If outside air is mixed with return air forventilation purposes, air mixture must remain above 50°F. toprevent condensation of flue gases which will corrode fur-nace parts.

ECONOMIZER OPTION

l COOLING SEASON Thermostat set at “Cool” and “Fan-Auto,” outside air damper goes to “minimum fresh air posi-tion” when Stage #l of cooling thermostat closes, energiz-ing mechanical cooling. When Stage#l issatisfied, mechan-ical cooling is de-energized, and outside air damper closes.(Damper always stays at “minimum fresh air position”duringcooling sequence if fan switch is at “Fan-On” and nightswitch’ is closed).

l INTERMEDIATE SEASON Same as for cooling season, ex-cept that as Stage #I of thermostat closes indoor blowermotor starts, compressor and outdoor fan motor remain off ifoutside air temperature is below outdoor air economizerthermostat setting. If outside and return air temperature risesabove or drops below mixed air thermostat setting, the out-side and return air dampers will reposition to maintain themixed air thermostat setting. If additional cooling is required,Stage #2 of the room thermostat will bring on outdoor con-denser fans and Stage #2 of mechanical cooling. Damperwill move to closed position when cooling Stage #l is satis-fied. Damper will move to “minimum fresh air position” whenfan switch is at “Fan-On” and cooling Stage #I is satisfied.The outside air damper will close when the night switch* isopened (night position), or whenever the indoor air blowershuts down.

l HEATING SEASON Damper always stays at “minimumfresh air position” while fan motor is operating. Outside airdamper closes when night switch’ opens or when blowermotor is off. “Minimum fresh air position” must not allowmixed air temperatures to furnace below 50°F. during heat-ing seasons. (-RGA series)‘Optional accessories - field msfalled

l NOTE: While maintenance of rooftop units is relativelysimple, proper operation and efficiency can be insured onlywhen a regular program of inspection and maintenance iscarried out. CAUTION -Disconnect power beforeservicing.

l FILTERS - Check the unit air filter every thirty to sixtydays and if obstructed clean or replace air filter at once, DONOT OPERATE THE UNIT WITHOUT A FILTER. Unit filters arelocated as shown on page 4. Factory supplied filters are 2”thick. Filter sizes are shown in Physical Data Table. Re-placement filters must be replaced by the same size as thoseoriginally supplied.

l LUBRICATION - All unit motors and compressors arefactory lubricated and normally do not require attention.

l EVAPORATOR COIL -Check annually and, if necessary,clean with a stiff brush, vacuum cleaner or compressed air.Coil can be reached through a side access panel.

l CONDENSER COIL - Check annually and, if necessary,

20

clean with a stiff brush, vacuum cleaner, compressed air, lowpressure water or steam.

l CONDENSATEDRAIN-Checkannuallyand, if necessary,clean drain pan and drain line. In winter, keep drain and trapdry or protect against freezeup.

l HEATING SECTION - GAS - A qualified service agencyshould check annually & if necessary clean unit base pan,combustion air inlet, combustionable outlet, combustion airblower wheel & flue ways including the heat exchanger.Clear pilot & burner if flame has deposited soot or if pilotflame has been reduced due to an obstruction in pilot orifice.

OUTER FLAME CONE

INNER FLAME CONE

BURNER CARRYOVER TUBE

v MAIN BURNER TUBE

TYPICAL BURNER FLAME AS VIEWEDALONG BURNER TUBE

RELATION OF PILOT FLAME TO THERMOCOUPLE

If there is a need, or an inspection is to be made, follow thisprocedure. It is recommended that this cleaning procedurebe performed by a qualified serviceman.

1

2

3

4

5

6

10

11

Turn off all power to the furnace and set the thermostatlever to the lowest temperature (heating mode).

Shut off the gas supply to the furnace either at the meteror at a manual valve in the supply piping.

Remove the control door from the furnace.

Turn the gas control knob to the “OFF” position.

Mark the individual wires to thegas control for identifyingpurposes when they are to be reconnected.

Removewires from thegascontrol, if thesystem containselectric ignrtron; disconnect the ignition wire to the ig-nitor from its supply end at the control box mounted onthe furnace.

Loosen the (2) screws securing the burner cover and liftthe burner cover off.

Using wrenches, separate the union in the supply pipingat the furnace.

Remove (4) screws (one at each corner of the burnerassembly mounting plate) that secures the burner as-sembly in position and withdraw the burner assemblyfrom the furnace.

Remove cover from exhaust box.

Each furnace section has a flue choke and a flue bafflesecured in each cell section outlet collar. Remove the (2)screws in each collar, lift off the flue choke and slide outthe flue baffle.

ACCESSORIES

l The economizer consists of an inner damper section, afresh air damper section and connecting linkage. The out-section contains a 90°, 24 volt damper motor, line to 24 volttransformer, and fresh air inlet screens. Integral with thedamper motor is an outdoor air change-over thermostat, amixed air thermostat and a minimum position potentiometer.l The Economizer option cannot be used on rear duct con-nected units (bottom duct connected units only).

- E c o n o m i z e r

-Accessory Roof top

48 CT T

LElectrical CharacteristicsI C =316012081230D =31601460

Cooling Size48=B & C Series 7% & 10 Ton

- Design Series

-Model Designation

RECOMMENDED SETTING OF ECONOMIZERCONTROLSl While setting may need to be varied to suit a particularapplication, the following setting will usually result in themost efficient operation.Change-over Thermostat 70°FMixed Air Thermostat 55O to 60°Minimum position poten- Minimum permitted by localtiometer - code or application

ECONOMIZER OPERATING SEQUENCE

l COOLING SEASON - Thermostat set at “Cool” and“Fan-Auto,” outside air damper goes to “minimum fresh airposition” when Stage #l of cooling thermostat closes, ener-gizing mechanical cooling. When Stage #l is satisfied,mechanical cooling is de-energized, and outside air dampercloses. (Damper always stays at “minimum fresh air posi-tion” during cooling sequence if fan switch is at “Fan-On”and night switch’ is closed.)l INTERMEDIATE SEASON -Same as for cooling season,except that as Stage #l of thermostat closes indoor blowermotor starts, compressor and outdoor fan motor remain off ifoutside air temperature is below outdoor air economizerthermostat setting. If outside and return air temperature risesabove or drops below mixed air thermostat setting, the out-side and return air dampers will reposition to maintain themixed air thermostat setting. If additional cooling is required,Stage #2 of the room thermostat will bring on outdoor con-denser fans and Stage #2 of mechanical cooling. Damperwill move to closed position when cooling Stage #l is satls-fied. Damper will move to “minimum fresh air position” whenfan switch IS at “Fan-On” and cooling Stage #l is satisfied.The outside air damper, will close when the night switch’ isopened (night position), or whenever the indoor blowershuts down.l HEATING SEASON - Damper always stays at “minimumfresh air position” while fan motor is operating. Outside airdamper closes when night switch’ opens or when blowermotor is off. “Minimum fresh air position” must not allowmixed air temperatures to Furnace below 50°F during heat-ing season.

OPTIONAL OPERATIONS

l REMOTE MINIMUM POSITION POTENTIOMETER - Anaccessory (RXRQ-DOl) or field supplied Honeywell S963manual potentiometer or similar control may be used toremotely adjust the minimum position of the fresh air dam-pers. To obtain 0 to 50% opening with the remote poten-tiometer, the motor mounted potentiometer must be set inthe closed position. Seedetail below for wiring connections.l NIGHT SWITCH -A manual or clock operated switch maybe used to close the fresh air damper at specified periodsallowing the most economical use of the heating system. Seedetail below for wiring connections.‘F ield Suppl ied 8 Instal led.

INSTALLING ECONOMIZER

l Before installing the economizer be certain that theeconomizer voltage rating is the same as the unit voltage. Ifnot the same, either obtain an economizer with the correctvoltage rating or change the economizer transformer. ModelRXRQ-A48C is used with 208/230 volt units, ModelRXRQ-A48D is used with 440/460 volt units. The economizermust have a 40 VA or larger, 460 to 24 volt transformer for usewith a 460 volt unit.l Remove the side inlet cap (upper panel). Install inter-damper assembly, and secure with two (2) sheet metalscrews. See figureshown. Attach economizer cabinet to unitusing screws that were removed from the inlet cap. Makesure seal between the economizer and the base unit is water-tight. Install connecting tie rod from fresh air damper to innerdamper and adjust so that when the fresh air damper is fullyclosed the inner damper is fully open. Route the 12 foot longmixed air bulb across the rear of all three blowers and secureas shown. Make sure that the mixed air bulb does not inter-fere with the replacement of filters.l Both theeconomizer and the base unit (Base unit is factorywired for economizer installation) are equipped with twoprewired plugs. The two (2) wire plugs carry line voltage (230or 460) and provides power to the economizer transformer.The 7 wire plugs are 24 volt control circuits. Make sure allpower to unit is disconnected, then remove dummy recepta-cles and plug each plug to matching receptacle.l Check operation in accordance with “Operating Sequ-ence”, then set change-over thermostat, mixed air thermos-tat and minimum position potentiometer per paragraphabove “Recommended Setting of Economizer Controls.”

FIELD 24 VOLT CONTROLWIRING CONNECTIONS

U S E COCORE~ #Ia A W G

WIRE

FOR LENGTHS MORE THAN

FIELD SUPPLIED REMOVENIGHT SWITCH

1

JUMPERIF PROVIDED (J2)r--7

( ‘yi--__-_ \,

‘\\

50 FT USE i16 A W G

POTENTIOMETER

ROOM THERMOSTAT

24 VOLT TERMINAL STRIPLOCATED IN FIELDWIRING BOX INCONDENSING SECTION

I FIELD 24 VOLT CONTROL WIRING CONNECTIONS

23

PERMANENT FILTERS RXRR-A48Four (4) 20x25~2 permanent filters These filters are made byResearch Products Corp. or an approved equivalent.

Permanent Filters

RT

X R R - A 4 8

1 i 1 LSizeUnit(7Y2-10)

Design Series

Permanent Filter

Accessory Rooftop

L--- Model Designation

TIME DELAY-RXRV-A50Time delay between compressors provides 30 second timedelay between cooling stages.

Time Delay Between Compressor

L Size Unit (71/2 - 10)

Design Series

Time Delay Between Compressor

Accessories Rooftop

Model Designation

26

ANTI-RECYCLE-RXRU-A51Anti-recycle keeps compressor off for five minutes afterpower or thermostat interruption, allowing system pressureto equalize. Starting during high pressure conditions canresult in shortened compressor life.

“91.‘.

Anti-Short Cycle

L XR U A 51

Size Unit (712 10)

Design Series

) !--_--Anti-Short C y c l e

I Accessory Rooftop

- Model Designation

COMB ANTI-SHORT CYCLE &TIME DELAY-RXRW-A51

Keep compressors off to allow system pressures to equalize& provides time delay between cooling stages.

Combination Anti-Short Cycle & Time Delay

”

.-

B_ T 7 1 LSizeUnit(71/2-10)

1 1 - D e s i g n S e r i e s

Combination Anti-Short Cycle &Time Delay

Accessory Rooftop

!---- Model Designation