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Page 46

507964-01

9/2019

Measure the intake air CFM. If the CFM is lower than the
design specified CFM for ventilation air, use the Unit
Controller to increase the damper percent open. If the CFM is
higher than specified, decrease the damper percent open.

Note - Intake air CFM can also be determined using the
outdoor air temperature, return air temperature and mixed
air temperature. Refer to the economizer or outdoor air
damper installation instructions.

TABLE 25

MINIMUM AND MAXIMUM CFM

Gas Heat Minimum CFM

Unit

Gas Heat Size

Airflow CFM

SG 120

Std. , Med.

2225

SG 120

High

2550

SG 240

Std. , Med.

4450

SG 240

High

5075

Electric Heat Minimum CFM

Unit

Heat Size (kW)

Airflow CFM

SC 120

0, 15, 20, 30, 40, 45, 60

3800

SC 240

0, 20, 30, 40, 60, 80, 90

8000

Cooling Minimum CFM - 220 CFM/ton

Unit

Blower Speed

Airflow CFM

SG/SC 120

Low, Med. Low, Med. High

2200

SG/SC 240

Low, Med. Low, Med. High

4400

Cooling Minimum CFM - 280 CFM/ton

Unit

Blower Speed

Airflow CFM

SG/SC 120

High

2800

SG/SC 240

High

5600

Smoke and Ventilation Minimum CFM - 150 CFM/ton

Unit

Not Applicable

Airflow CFM

SG/SC 120

NA

1500

SG/SC 240

NA

3000

Heating and Cooling Maximum CFM - 480 CFM/ton

Unit

Blower Speed

Airflow CFM

SG/SC 120

High

4800

SG/SC 240

High

9600

Set Minimum Position 2

Use the same menu in the Unit Controller to set “Min OCP

Blwr High” for the blower CFM above the “midpoint” CFM.

When navigating into this menu, the Unit Controller will

bring on the corresponding blower speed and allow damper

position adjustment.

Settings / Control / MSAV / Damper / High Speed

Measure the intake air CFM. If the CFM is lower than the

design specified CFM for ventilation air, use the Unit

Controller to increase the damper percent open. If the CFM is

higher than specified, decrease the damper percent open.

Note - Intake air CFM can also be determined using the

outdoor air temperature, return air temperature and mixed

air temperature. Refer to the economizer or outdoor air

damper installation instructions.

MSAV

TM

 Operation 

This is a summary of cooling operation. Refer to the

sequence of operation provided in the Engineering

Handbook or Service Manual for more detail.

A-Two-Stage T'Stat; 2- and 4-Compressor Units

1-Economizer With Outdoor Air Suitable

Y1 Demand -

Compressors Off
Blower Cooling Low
Dampers modulate

Y2 Demand -

Compressors Off
Blower Cooling High
Dampers Modulate

Note - If dampers are at maximum open for three minutes,
compressor 1 and 2 are energized and blower stays on
cooling high.

2-No Economizer or Outdoor Air Not Suitable

Y1 Demand -

First-stage Compressors On

(compressor 1 on 120 units,
compressor 1 & 2 on 240 units)

Blower Cooling Low
Dampers Minimum Position

Y2 Demand -

All Compressors On
Blower Cooling High
Dampers Minimum Position

B-Zone Sensor (4 Clg. Stages), 4-Compressor Units

(240 Units)

1-Economizer With Outdoor Air Suitable

Y1 Demand -

Summary of Contents for SCH036

Page 1: ...43 MSAVt Unit Start Up Page 45 MSAVt Operation Page 46 Direct Drive Start Up Page 47 Hot Gas Reheat Startup Page 49 Economizer Start Up Page 53 Service Page 55 Factory Control Parameter Settings Page...

Page 2: ...IEW LIFTING HOLES For Rigging Front and Back 81 2057 82 7 8 2105 28 7 8 733 5 1 4 133 72 1 4 1835 41 3 8 1050 3 1 2 89 37 7 8 962 1 1 2 38 GAS SUPPLY 115V OUTLET Factory Installed Inside Unit Field Wi...

Page 3: ...FORKLIFT SLOTS 51 3 8 1305 47 7 8 1216 77 5 16 1964 86 7 16 2196 5 3 8 137 5 1 4 133 BOTTOM OUTDOOR AIR INTAKE CIRCUIT BREAKER COVER FLUE OUTLET CONDENSER FANS AND GUARDS 2 OUTDOOR AIR HOOD Factory In...

Page 4: ...28 711 28 711 4 102 9 229 20 508 20 508 18 457 OUTDOOR AIR HOOD Factory Installed Option CONDENSATE DRAIN 5 3 8 137 3 1 4 83 GAS SUPPLY CIRCUIT BREAKER COVER 115V OUTLET Factory Installed Inside Unit...

Page 5: ...OWER CONDENSATE DRAIN FILTERS FOUR 16 X 20 X 2 ECONOMIZER DAMPERS OPTIONAL BURNERS FILTER DRIER UNIT CONTROLLER REHEAT COIL SC 036 060 Parts Arrangement EVAPORATOR COIL CONDENSER FANS CONDENSER COIL C...

Page 6: ...FILTER DRIERS SUPPLY AIR VFD CONDENSER AIR INTAKE THROUGH UNIT BASE COMBUSTION AIR INDUCER BURNERS GAS VALVE REHEAT COIL SC 120 Parts Arrangement BLOWER MOTOR CONDENSER FANS 2 CONDENSER COILS COMPRESS...

Page 7: ...NDENSATE DRAIN FILTERS TWELVE 20 X 20 X 2 ECONOMIZER DAMPERS OPTIONAL UNIT CONTROLLER SUPPLY AIR VFD FILTER DRIERS REHEAT COIL SC 240 Parts Arrangement BLOWER MOTOR FILTERS TWELVE 20 X 20 X 2 ELECTRIC...

Page 8: ...th a total of 10 ton cooling capacities The SG 240 gas electric packaged rooftop unit is available in 260 000 360 000 or 480 000 Btuh heating inputs The SC 240 cooling packaged rooftop unit is the sam...

Page 9: ...ctions NOTE The Commonwealth of Massachusetts stipulates these additional requirements S Gas units shall be installed by a licensed plumber or gas fitter only S The gas cock must be T handle type Unit...

Page 10: ...holes in unit base rail See figure 3 1 Detach wooden base protection before rigging 2 Connect rigging to the unit base using both holes in each corner 3 All panels must be in place for rigging 4 Place...

Page 11: ...ve See figure 5 or 6 for gas supply piping entering outside the unit See figure 7 for gas supply piping entering bottom the unit Compounds used on threaded joints of gas piping shall be resistant to t...

Page 12: ...gas leaks WARNING FIRE OR EXPLOSION HAZARD Failure to follow the safety warnings exactly could re sult in serious injury death or property damage Never test for gas leaks with an open flame Use a comm...

Page 13: ...rd Screen Option Outdoor air hood is shipped folded down over the horizontal supply air opening Install hood as follows 1 Remove left side from hood top panel See figure 10 2 Remove and retain screws...

Page 14: ...end of air hood 6 Install back filter bracket on unit division panel as shown in figure 14 7 Secure side seals to the hood sides as shown in figure 15 8 Install longer front filter bracket on hood to...

Page 15: ...dead spots behind doors and in corners hot or cold air from ducts radiant heat from sun or appliances concealed pipes and chimneys B Control Wiring The Unit Controller will operate the unit from a the...

Page 16: ...ring connections as shown in figure 16 for Thermostat Mode or figure 17 for Zone Sensor Mode In addition connect either a humidity sensor or a dehumidification input See figure 18 or 19 for humidity s...

Page 17: ...ower Operation Note On units with staged blowers use the Unit Controller to start the blower Refer to the appropriate start up section Initiate blower demand at thermostat according to instructions pr...

Page 18: ...WS TO SLIDE BLOWER ASSEMBLY OUT OF UNIT BELT TENSION ADJUSTING BOLT TURN CLOCKWISE TO TIGHTEN TO INCREASE BELT TENSION 1 Loosen front and back screws securing pivoting motor base to slotted arm 2 Turn...

Page 19: ...OSEN FOUR SCREWS TO AD JUST BELT TENSION BLOWER MOTOR REMOVE SCREWS TO SLIDE BLOWER ASSEMBLY OUT OF UNIT LOOSEN SCREWS TO ADJUST BELT TENSION PULLEY ALLEN SCREW BELT TENSION ADJUSTING SCREWS BLOWER AS...

Page 20: ...n in table 2 TABLE 2 Minimum and Maximum Pulley Adjustment Belt Minimum Turns Open Maximum Turns Open A Section 0 5 B Section 1 6 No minimum number of turns open when B belt is used on pulleys 6 O D o...

Page 21: ...33 2158 460 2202 486 2244 513 2285 542 2327 573 1400 1819 273 1873 299 1926 324 1977 350 2027 377 2075 404 2122 431 2168 459 2212 486 2255 515 2297 543 2338 572 2378 602 2419 635 1500 1935 318 1987 34...

Page 22: ...525 0 72 569 0 83 613 0 93 653 1 02 689 1 11 724 1 20 758 1 31 793 1 44 829 1 58 864 1 72 897 1 85 928 1 97 956 2 08 3200 547 0 84 591 0 95 634 1 05 672 1 14 707 1 23 741 1 34 776 1 47 812 1 61 848 1...

Page 23: ...686 2 50 722 2 70 759 2 89 796 3 08 5400 346 0 92 400 1 12 444 1 33 484 1 51 522 1 67 556 1 86 589 2 04 622 2 23 655 2 41 690 2 60 727 2 79 764 2 98 801 3 17 5600 355 0 96 407 1 17 450 1 40 490 1 58 5...

Page 24: ...2234 524 2282 554 2329 586 1400 1738 266 1803 293 1865 320 1923 347 1979 373 2031 401 2082 428 2131 456 2179 485 2227 514 2274 545 2320 575 2366 607 2411 641 1500 1855 305 1915 333 1973 361 2028 389...

Page 25: ...1 33 813 1 43 843 1 52 872 1 60 902 1 69 3000 489 0 74 525 0 81 564 0 89 607 0 97 649 1 06 688 1 16 725 1 27 761 1 38 795 1 48 826 1 58 857 1 66 887 1 75 918 1 84 3200 506 0 86 543 0 93 583 1 01 625...

Page 26: ...1 59 551 1 77 585 1 95 617 2 13 651 2 32 686 2 50 722 2 70 759 2 89 796 3 08 5400 346 0 92 400 1 12 444 1 33 484 1 51 522 1 67 556 1 86 589 2 04 622 2 23 655 2 41 690 2 60 727 2 79 764 2 98 801 3 17 5...

Page 27: ...LED OPTIONS FIELD INSTALLED ACCESSORY AIR RESISTANCE in w g Air Volume cfm Dehumidification Coil Economizer Filters MERV 13 036 060 MODELS 800 0 00 0 04 0 05 1000 0 00 0 04 0 07 1200 0 01 0 04 0 07 14...

Page 28: ...5 75 4 staged 5 staged 520 685 685 865 7 5 8 63 7 staged 770 965 TABLE 13 SG SC 120 Manufacturer s Numbers Drive No DRIVE COMPONENTS ADJUSTABLE SHEAVE FIXED SHEAVE BELTS Supplier No OEM Part No Suppli...

Page 29: ...thermostat demand will energize compressor 2 On units with an economizer when outdoor air is acceptable a first stage demand will energize the economizer a second stage demand will energize compresso...

Page 30: ...ANT Mineral oils are not compatible with R410A If oil must be added it must be a polyol ester oil CIRCUIT 1 CONDENSER COIL FIGURE 27 SG SC 120 MSAVt UNIT REFRIGERANT CIRCUITS 2 CIRCUIT 2 CONDENSER COI...

Page 31: ...rant to the system D If measured liquid temperature is lower than the target liquid temperature recover some refrigerant from the system 5 Add or remove charge in increments Allow the system to stabil...

Page 32: ...21 403 124 457 118 244 120 280 122 321 126 364 129 411 132 465 136 252 140 286 142 326 144 375 147 428 150 483 152 278 157 303 162 338 166 381 169 430 172 486 Circuit 2 110 250 112 286 116 329 117 374...

Page 33: ...17 419 119 487 117 245 119 280 120 326 123 373 126 428 129 484 135 253 137 286 140 329 142 375 146 432 149 494 151 267 157 296 162 340 165 382 168 434 172 497 Circuit 3 104 236 104 273 107 323 109 371...

Page 34: ...0 100 110 120 SG SC 036 Charging Curves Reheat 580979 01 Outdoor Temperature F 110 120 130 140 150 160 170 180 Suction Pressure psig 115 105 95 85 75 65 60 70 80 90 100 110 120 110 120 130 140 150 160...

Page 35: ...Page 35 SGH SCH036 060 120 240 Suction Pressure psig 115 105 95 85 75 65 60 70 80 90 100 110 120 SG SC 060 Charging Curves Reheat 580980 01 Outdoor Temperature F 110 120 130 140 150 160 170 100...

Page 36: ...Temperature F 115 105 95 85 75 65 Circuit 1 SG SC 120 Reheat No Reheat 580740 02 110 120 130 140 150 160 170 100 60 70 80 90 100 110 120 130 Suction Pressure psig Outdoor Temperature F 115 105 95 85 7...

Page 37: ...115 105 95 85 75 65 60 70 80 90 100 110 120 100 110 120 130 140 150 160 Circuit 1 SG SC 240 No Reheat 580974 01 170 Suction Pressure psig 115 105 95 85 75 65 Circuit 2 SG SC 240 No Reheat 580974 01 Ou...

Page 38: ...80 90 100 110 120 Circuit 3 SG SC 240 No Reheat 580974 01 Outdoor Temperature F 100 110 120 130 140 150 160 170 Outdoor Temperature F Suction Pressure psig 115 105 95 85 75 65 70 80 90 100 110 120 11...

Page 39: ...60 70 80 90 100 110 120 100 110 120 130 140 150 160 Circuit 1 SG SC 240 Reheat 580976 01 Outdoor Temperature F 170 Suction Pressure psig 115 105 95 85 75 65 Circuit 2 SG SC 240 Reheat 580976 01 Outdo...

Page 40: ...70 80 90 100 110 120 Circuit 3 SG SC 240 Reheat 580976 01 Outdoor Temperature F 100 110 120 130 140 150 160 170 Suction Pressure psig 115 105 95 85 75 65 70 80 90 100 110 120 110 120 130 140 150 160...

Page 41: ...ompressor 3 4 Controller respectively Condenser fan 3 is de energized when BOTH S11 and S84 open due to low pressure Condenser fan 4 is de energized when BOTH S85 and S94 open due to low pressure 4 Fr...

Page 42: ...OFF Do not force 6 Wait five 5 minutes to clear out any gas If you then smell gas STOP Immediately call your gas supplier from a neighbor s phone Follow the gas supplier s instructions If you do not...

Page 43: ...to HEAT position Primary Limit Location Limit controls are factory set and are not adjustable SG 036 060 On the vestibule to the right of the combustion air inducer See figure 32 SG 120 Upper right co...

Page 44: ...nd restriction 3 Remove temporary gas meter if installed NOTE To obtain accurate reading shut off all other gas appliances connected to meter TABLE 23 GAS METER CLOCKING CHART Unit Input Rate Btuh Sec...

Page 45: ...M Cooling High CFM1 Cooling Low CFM1 Vent CFM 1The Unit Controller will prompt when more cooling stages are available depending on the number of compressors and the control mode 3 Adjust the blower RP...

Page 46: ...the blower CFM above the midpoint CFM When navigating into this menu the Unit Controller will bring on the corresponding blower speed and allow damper position adjustment Settings Control MSAV Damper...

Page 47: ...ake sure blower CFM is within limitations shown in table 27 Refer to the Unit Controller manual provided with unit SETUP TEST BALANCE BLOWER 3 Once all four speeds are entered the target highest of th...

Page 48: ...POSITION BLOWER ON HIGH X X Measure the intake air CFM If the CFM is lower than the design specified CFM for ventilation air use the Unit Controller to increase the damper percent open If the CFM is...

Page 49: ...ndoor relative humidity rises above 60 default The reheat setpoint can be adjusted by changing Unit Controller Settings Control menu A setting of 100 will operate reheat from an energy management syst...

Page 50: ...IR REHEAT MODE REFRIGERANT ROUTING 240 FIGURE 37 REHEAT COIL REHEAT COIL EVAPORATOR COIL DEHUMIDIFIED NEUTRAL AIR MIXED INDOOR OUTDOOR AIR CONDENSER COIL NOTE Refrigerant circuits one and two operates...

Page 51: ...Compressor 2 Cooling Blower High Speed Reheat Y1 Y2 Compressor 1 Cooling Compressor 2 Cooling Blower High Speed If there is no reheat demand and outdoor air is suitable free cooling will operate If t...

Page 52: ...1 Reheat Compressor 2 3 4 Cooling3 Reheat Y1 Y2 Y3 Y4 Compressor 1 2 3 4 Cooling5 Cooling stage is initiated when zone temperature is higher than the cooling setpoint plus the appropriate stage differ...

Page 53: ...is suitable Param eter M Motorized Out door Air Dampers None Dampers do not modulate dampers will open to minimum position during the occupied time period and close during the unoccupied time period...

Page 54: ...dampers further or to keep them open The IAQ function is not energized during the unoccupied or night time period TABLE 32 ECONOMIZER OPERATION Standard Two Stage Thermostat Default Option THERMOSTAT...

Page 55: ...ent for use in Canada TABLE 35 Number and Size of Filter By Unit SG SC Unit Qty Filter Size inches mm 036 060 4 16 X 20 X 2 406 X 508 X 51 120 4 20 X 25 X 2 508 X 635 X 51 240 12 20 X 20 X 2 508 X 508...

Page 56: ...000 BTUH 5 BURNERS SENSOR IGNITOR SENSOR IGNITOR 70 000 BTUH 3 BURNERS SENSOR IGNITOR D Combustion Air Inducer SG Units A combustion air proving switch checks combustion air inducer operation before a...

Page 57: ...off any dust from housing Clean accumulated dust from front of flue box cover 5 Return combustion air blower motor and vent connector to original location and secure with retained screws It is recomme...

Page 58: ...rovided with each unit Tables 37 through 42 show factory settings in degrees of fan CFM etc Record adjusted settings on the parameter label located inside the compressor access panel TABLE 37 580902 0...

Page 59: ...er exhaust operation TABLE 42 580904 01 SG SC 240 Staged Blower Parameter Factory Setting Field Setting Description 240 Note Any changes to Smoke CFM setting must be adjusted before the other CFM sett...

Page 60: ..._________ Cooling Checks Compressor Rotation j Ambient Temp ________Return Air Temp ________ Supply Air Temp ________ Compressor Amps Compressor Volts Pressures Condenser Fan Amps CC Heater Amps L1 L2...

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