Carrier 48FC M20 Series Service And Maintenance Instructions
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Carrier 48FC M20 Series Service And Maintenance Instructions

Single package rooftop gas heat/electric cooling unit with puron (r-410a) refrigerant 17.5-27.5 nominal tons
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Service and Maintenance Instructions
CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2
UNIT ARRANGEMENT AND ACCESS . . . . . . . . . . . . 3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 3
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SUPPLY FAN (BLOWER) SECTION . . . . . . . . . . . . . . 4
Supply Fan (Direct-Drive) . . . . . . . . . . . . . . . . . . . . . . 4
Staged Air Volume . . . . . . . . . . . . . . . . . . . . . . . . . . 13
COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . 13
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Evaporator Coil Metering Devices . . . . . . . . . . . . . . 15
TXV Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Replacing TXV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
PURON (R-410A) REFRIGERANT . . . . . . . . . . . . . . . 17
Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 17
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Replacing Compressor . . . . . . . . . . . . . . . . . . . . . . . 26
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . 26
Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Condenser-Fan Adjustment . . . . . . . . . . . . . . . . . . . 26
Troubleshooting Cooling System . . . . . . . . . . . . . . 27
CONVENIENCE OUTLETS . . . . . . . . . . . . . . . . . . . . 28
Convenience Outlets . . . . . . . . . . . . . . . . . . . . . . . . 28
Installing Weatherproof Cover . . . . . . . . . . . . . . . . . 28
Non-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Unit-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Fuse on Powered Type . . . . . . . . . . . . . . . . . . . . . . . 29
SMOKE DETECTORS . . . . . . . . . . . . . . . . . . . . . . . . 29
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Smoke Detector Sensor . . . . . . . . . . . . . . . . . . . . . . 29
Smoke Detector Locations . . . . . . . . . . . . . . . . . . . . 30
SENSOR AND CONTROLLER TESTS . . . . . . . . . . . 32
Sensor Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Controller Alarm Test . . . . . . . . . . . . . . . . . . . . . . . . 32
Dirty Controller Test . . . . . . . . . . . . . . . . . . . . . . . . . 32
Dirty Sensor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480333-01
Single Package Rooftop Gas Heat/Electric Cooling Unit
Page
Printed in U.S.A.
Form 48FC-20-30-01SM
with Puron
®
17.5-27.5 Nominal Tons
Changing the Dirt Sensor Test . . . . . . . . . . . . . . . . .33
Remote Station Test . . . . . . . . . . . . . . . . . . . . . . . . .33
Dirty Sensor Test Using an SD-TRK4 . . . . . . . . . . .34
Detector Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
PROTECTIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . .35
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . .35
Relief Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Control Circuit, 24-V . . . . . . . . . . . . . . . . . . . . . . . . .36
GAS HEATING SYSTEM . . . . . . . . . . . . . . . . . . . . . .37
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Fuel Types and Pressures . . . . . . . . . . . . . . . . . . . .37
Flue Gas Passageways . . . . . . . . . . . . . . . . . . . . . . .38
Combustion-Air Blower . . . . . . . . . . . . . . . . . . . . . . .38
Burners and Igniters . . . . . . . . . . . . . . . . . . . . . . . . .38
Burner Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Orifice Replacement . . . . . . . . . . . . . . . . . . . . . . . . .42
Troubleshooting Heating System . . . . . . . . . . . . . .44
SYSTEMVU CONTROL SYSTEM . . . . . . . . . . . . . . . .46
SystemVu Interface . . . . . . . . . . . . . . . . . . . . . . . . . .46
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . .46
ECONOMIZER SYSTEMS . . . . . . . . . . . . . . . . . . . . .47
EconoMi$er2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
PRE-START-UP/START-UP . . . . . . . . . . . . . . . . . . . .66
START-UP, GENERAL . . . . . . . . . . . . . . . . . . . . . . . .67
Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Additional Installation/Inspection . . . . . . . . . . . . . .67
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . .68
Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . .68
Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . .68
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . .68
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Main Burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . .68
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . .69
START-UP, SYSTEMVU CONTROLS . . . . . . . . . . . .69
GENERAL FAN PERFORMANCE NOTES . . . . . . . . .74
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . .70
Pg 1
48FC**20-30
(R-410A) Refrigerant
1-24
Replaces: NEW

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Summary of Contents for Carrier 48FC M20 Series

  • Page 1: Table Of Contents

    48FC**20-30 Single Package Rooftop Gas Heat/Electric Cooling Unit with Puron ® (R-410A) Refrigerant 17.5-27.5 Nominal Tons Service and Maintenance Instructions CONTENTS Changing the Dirt Sensor Test ....33 Remote Station Test .

  • Page 2: Safety Considerations

    APPENDIX B — PHYSICAL DATA ....71 APPENDIX C — GAS HEAT DATA ....73 WARNING APPENDIX D —...

  • Page 3: Unit Arrangement And Access

    SEASONAL MAINTENANCE UNIT ARRANGEMENT AND ACCESS These items should be checked at the beginning of each season (or General more often if local conditions and usage patterns dictate): Figures 1 and 2 show general unit arrangement and access Air Conditioning locations.

  • Page 4: Supply Fan (Blower) Section

    OUTSIDE AIR HOOD SUPPLY FAN (BLOWER) SECTION Outside air hood inlet screens are permanent aluminum-mesh type filters. Check these for cleanliness. Remove the screens when cleaning is required. Clean by washing with hot low-pressure wa- WARNING ter and soft detergent and replace all screens before restarting the ELECTRICAL SHOCK HAZARD unit.
  • Page 5 EVALUATING MOTOR SPEED NOTE: For units equipped with the Humidi-MiZer option, when replacing the UCB cut JMP 1,2 and 3 in the REHEAT/HP section The direct drive ECM blower motor uses a constant speed design. of the replacement UCB. Motor speed is controlled by a 0-10 vdc signal, where 10 vdc is equal to motor’s maximum rpm.
  • Page 6 ESP in. wg Factory Setting: Calculator 9.0 V 6000 Field Setting: 6500 Record field setting here 7000 7500 8000 Switch Range: 8500 9000 4.1 - 7.5 9500 10.0 6.9 - 8.7 10000 7.7 - 10.0 Field Accessories: Economizer * Overlap in A, B, C switch range designed for maximum field adjustment potential.
  • Page 7 ESP in. wg Calculator 1250 1348 1441 1528 1610 1688 1762 1832 1899 1963 6000 1336 1428 1515 1598 1677 1753 1824 1893 1959 2021 6500 1423 1509 1591 1670 1746 1819 1888 1955 2020 2081 7000 1510 1591 1669 1744 1817 1887...
  • Page 8 TROUBLESHOOTING THE ECM MOTOR EcoBlue™ motors are designed with several built-in protections included in the motor software. If the motor detects a fault it will safely shut down. See Table 4, “Supply Fan Motor Logic and Safety Relays” on page 36 for a complete list. Troubleshooting the motor requires a voltmeter.
  • Page 9 Removing the Motor and Fan Assembly NOTE: Due to press fit design of composite Rotor on Motor, it is highly recommended that any time a motor is replaced the fan ro- tor is replaced as well. The rest of the assembly may be reused. See Fig.
  • Page 10 Disassembling Standard/Medium Motor and Fan Assembly Disassembling High Static Motor and Fan Assembly See Fig. 12. See Fig. 13. NOTE: Refer to “Model Number Nomenclature” on page 70, NOTE: Refer to “Model Number Nomenclature” on page 70, position 10 for specific unit requirements. position 10 for specific unit requirements.
  • Page 11 Reassembly of Standard/Medium Motor and Fan Assembly Reassembly of High Static Motor and Fan Assembly See Fig. 14. See Fig. 15. NOTE: Refer to “Model Number Nomenclature” on page 70, NOTE: Refer to “Model Number Nomenclature” on page 70, position 10 for specific unit requirements. position 10 for specific unit requirements.
  • Page 12 Reinstalling Motor and Fan Assembly See Fig. 16. Align motor harness/grommet at ~7 o’clock (facing installer) and align the bottom flats on right and left sides of fan stator with fan deck ribs. Drop fan assembly down into fan deck opening and slide back until aluminum stator is under the rear fan deck brackets.

  • Page 13: Staged Air Volume

    ROUTINE CLEANING OF COIL SURFACES Staged Air Volume All 48FC units with EcoBlue™ technology come factory set to Periodic cleaning with Totaline environmentally balanced coil ® automatically adjust the indoor fan motor speed in sequence with cleaner is essential to extend the life of coils. This cleaner is avail- the unit’s ventilation, cooling, and heating operation.
  • Page 14 Clean the outer coil surface to remove surface loaded Support (Field-Supplied) fibers or dirt. See “Remove Surface Loaded Fibers” on page 13 for details. 10. Use a water hose or other suitable equipment to flush down Top Panel between the 2 coil sections to remove dirt and debris. If a coil cleaner is used be sure to rinse the coils completely before reassembly.

  • Page 15: Evaporator Coil

    Totaline Environmentally Balanced Coil Cleaner Application THERMOSTATIC EXPANSION VALVE (TXV) Equipment The TXV is a bi-flow, bleed port expansion valve with an external • 2-1/2 gallon garden sprayer equalizer. The TXVs are specifically designed to operate with • Water rinse with low velocity spray nozzle Puron refrigerant.

  • Page 16: Refrigerant System Pressure Access Ports

    Refrigerant System Pressure Access Ports V I E W W I T H T X V B U L B There are two access ports in the system: on the suction tube near I N S U L A T I O N C O V E R R E M O V E D the compressor and on the discharge tube near the compressor.

  • Page 17: Puron (R-410A) Refrigerant

    Amount of refrigerant charge is listed on the unit’s nameplate. Re- fer to Carrier GTAC2-5 Charging, Recovery, Recycling and Rec- Outdoor Temperature ..... . . 85°F (29°C) lamation training manual and the following procedures.
  • Page 18 COOLING CHARGING CHARTS 17.5 Ton Entry Tier R-410A — Charging Chart (Unit must have both compressors and outdoor fans on high speed) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068...
  • Page 19 COOLING CHARGING CHARTS 20 Ton Entry Tier R-410A — Charging Chart (Unit must have both compressors and outdoor fans on high speed) 59.9 Add charge if Above Curve 48.8 37.7 26.6 15.5 Remove Charge if Below the Curve -6.7 1034 1379 1723 2068...
  • Page 20 COOLING CHARGING CHARTS 25 Ton Entry Tier R-410A — Charging Chart (Unit must have both compressors and outdoor fans on high speed) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068...
  • Page 21 COOLING CHARGING CHARTS 27.5 Ton Entry Tier R-410A — Charging Chart (Unit must have both compressors and outdoor fans on high speed) 59.9 Add charge if Above Curve 48.8 37.7 26.6 15.5 Remove Charge if Below the Curve -6.7 1034 1379 1723 2068...
  • Page 22 COOLING CHARGING CHARTS 17.5 Ton Entry Tier Humidi-MiZer R-410A — Charging Chart (Unit must run in subcooling mode) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068 2413 2758 3102 3447...
  • Page 23 COOLING CHARGING CHARTS 20 Ton Entry Tier Humidi-MiZer R-410A — Charging Chart (Unit must run in subcooling mode) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068 2413 2758 3102 3447...
  • Page 24 COOLING CHARGING CHARTS 25 Ton Entry Tier Humidi-MiZer R-410A — Charging Chart (Unit must run in subcooling mode) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068 2413 2758 3102 3447...
  • Page 25 COOLING CHARGING CHARTS 27.5 Ton Entry Tier Humidi-MiZer R-410A — Charging Chart (Unit must run in subcooling mode) 59.9 Add charge if Above Curve 48.8 37.7 26.6 Remove Charge if Below the Curve 15.5 -6.7 1034 1379 1723 2068 2413 2758 3102 3447...

  • Page 26: Compressor

    COMPRESSOR Compressor Rotation Lubrication CAUTION The compressor is charged with the correct amount of oil at the factory. EQUIPMENT DAMAGE HAZARD Failure to follow this caution can result in premature wear and damage to equipment. CAUTION Scroll compressors can only compress refrigerant if rotat- UNIT DAMAGE HAZARD ing in the right direction.

  • Page 27: Troubleshooting Cooling System

    Troubleshooting Cooling System Refer to Table 1 for additional troubleshooting topics. Table 1 — Troubleshooting SYMPTOM CAUSE SOLUTION Power failure. Call power company. Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker. Determine root cause. Defective thermostat, contactor, transformer. Replacement component.

  • Page 28: Convenience Outlets

    Press the gasket over the screw heads. Slip the backing CONVENIENCE OUTLETS plate over the screw heads at the keyhole slots and align with the gasket; tighten the two screws until snug (do not over-tighten). WARNING Mount the weatherproof cover to the backing plate as ELECTRICAL OPERATION HAZARD shown in Fig.

  • Page 29: Duty Cycle

    SMOKE DETECTORS Smoke detectors are available as factory-installed options on 48FC models. Smoke detectors may be specified for supply air only, for return air without or with economizer, or in combination of supply air and return air. Return air smoke detectors are ar- ranged for vertical return configurations only.

  • Page 30: Smoke Detector Locations

    Air is introduced to the duct smoke detector sensor’s sensing chamber through a sampling tube that extends into the HVAC duct and is directed back into the ventilation system through a (shorter) exhaust tube. The difference in air pressure between the two tubes pulls the sam- pled air through the sensing chamber.

  • Page 31: Fiop Smoke Detector Wiring And Response

    RETURN AIR SMOKE DETECTOR SENSOR WITH ECONOMIZER The sampling tube is inserted through the side plates of the econo- mizer housing, placing it across the return air opening on the unit basepan. The holes in the sampling tube face into the return air stream.

  • Page 32: Sensor And Controller Tests

    Fig. 41 — Typical Smoke Detector System Wiring SENSOR AND CONTROLLER TESTS Controller Alarm Test The controller alarm test checks the controller’s ability to initiate Sensor Alarm Test and indicate an alarm state. The sensor alarm test checks a sensor’s ability to signal an Controller Alarm Test Procedure alarm state.

  • Page 33: Dirty Sensor Test

    Remote Station Test The remote station alarm test checks a test/reset station’s ability to IMPORTANT: Failure to follow this ALERT can result in initiate and indicate an alarm state. an unnecessary evacuation of the facility. Pressing the controller’s test/reset switch for longer than seven seconds will put the duct detector into the alarm state and IMPORTANT: Failure to follow this ALERT can result in activate all automatic alarm responses.

  • Page 34: Dirty Sensor Test Using An Sd-Trk4

    Indicators IMPORTANT: Failure to follow this ALERT can result in NORMAL STATE an unnecessary evacuation of the facility. The smoke detector operates in the normal state in the absence of Holding the test magnet to the target area for longer than seven any trouble conditions and when its sensing chamber is free of seconds will put the detector into the alarm state and activate smoke.

  • Page 35: Troubleshooting

    NOTE: All troubles are latched by the duct smoke detector. The PROTECTIVE DEVICES trouble condition must be cleared and then the duct smoke detec- Compressor Protection tor must be reset in order to restore it to the normal state. OVERCURRENT RESETTING ALARM AND TROUBLE CONDITION TRIPS The compressor has internal line-break motor protection.

  • Page 36: Relief Device

    LOW PRESSURE SWITCH CONDENSER FAN MOTOR PROTECTION The system is protected against a loss of charge and low evapora- The condenser fan motor is internally protected against tor coil loading condition by a low pressure switch located on the over-temperature. suction line near the compressor.

  • Page 37: Gas Heating System

    GAS HEATING SYSTEM Table 7 — Liquid Propane Supply Line Pressure General Ranges The heat exchanger system consists of a gas valve feeding multi- UNIT MODEL UNIT SIZE MIN. MAX. ple in-shot burners off a manifold. The burners fire into matching 11.0 in.

  • Page 38: Flue Gas Passageways

    The blower wheel can be cleaned at this point. If additional Flue Gas Passageways cleaning is required, continue with Steps 4 and 5. To inspect the flue collector box and upper areas of the heat ex- Remove the blower from the motor shaft by removing two changer: setscrews.
  • Page 39 MAIN BURNERS Remove the screws at the base of the burner partition panel (see Fig. 53) and slide out the panel. To access burners, remove the control box access panel and Disconnect gas piping at unit gas valve. slide out burner partition panel. At the beginning of each heat- Remove wires connected to gas valve.
  • Page 40 Inducer Fan Gas Valve Motor Manifold Gas Limit Switch Pressure Down Shot Gas Valve BURNERS Gas Valve Rollout Switch Unit Center Post Burner Partition Panel Fig. 53 — Burner Partition Pane and Unit Center Post Spark Igniter Flame Sensor Fig. 52 — Burner Tray Details Integrated Gas Controller (IGC) Fig.
  • Page 41 REMOVING THE HEAT EXCHANGER Disconnect a gas pipe union and remove the gas manifold with the gas valve. The following procedure details the steps to remove the heat ex- Remove the two screws attaching the burner rack to the changed from the unit. vestibule plate (see Fig.

  • Page 42: Burner Ignition

    GAS VALVE LIMIT SWITCH All three-phase models are equipped with 2-stage gas valves. Remove the indoor blower access panel. Limit switch is located See Fig. 56 for locations of adjustment screws and features on on the heat exchanger cover panel. See Fig. 51. the gas valve.
  • Page 43 RED LED - STATUS Fig. 57 — Integrated Gas Control (IGC) Board...

  • Page 44: Troubleshooting Heating System

    MINIMUM HEATING ENTERING AIR TEMPERATURE Thermostat When operating on first stage heating, the minimum temperature of air entering the dimpled heat exchanger is 50°F continuous and 45°F intermittent for standard heat exchangers and 40°F continuous and 35°F intermittent for stainless steel heat ex- OALT changers.
  • Page 45 Table 11 — IGC Board LED Alarm Codes a,b,c,d ACTION TAKEN BY FLASH DESCRIPTION RESET METHOD PROBABLE CAUSE CONTROL CODE Normal Operation — — — Hardware Failure No gas heating. Loss of power to the IGC. Check 5 amp fuse —...

  • Page 46: Systemvu Control System

    Through the SystemVu interface, the user can access all of the The SystemVu control system is fully communicating and cable- inputs and outputs to check on their values and status, config- ready for connection to the Carrier Comfort Network (CCN), ®...

  • Page 47: Economizer Systems

    ECONOMIZER SYSTEMS The unit may be equipped with a factory-installed or accessory Outside Air (field-installed) economizer system. Three types are available: Temperature Sensor two with logic control systems (EconoMi$er X and EconoMi$er ® Low Ambient EconoMi$er IV Sensor IV) and one without a control system (EconoMi$er2). See Controller (W7212) Fig.

  • Page 48: Economi$Er2

    EconoMi$er2 IMPORTANT: The optional EconoMi$er 2 does not ® include a controller. The EconoMi$er2 is operated by a 4 mA to 20 mA signal from an existing field-supplied con- troller. See Fig. 63 for wiring information. BLACK Transformer Ground BLUE 500 OHM Resistor VIOLET...

  • Page 49: Economi$Er Iv (Field-Installed Accessory)

    EconoMi$er IV (Field-Installed Accessory) IMPORTANT: For 48FC*20-30 rooftop units EconoMi$er IV is available as a field-installed accessory only. ECONOMI$ER IV STANDARD SENSORS Troubleshooting instructions are enclosed. A functional view of the EconoMi$er ® IV accessory is shown in Fig. 64. Typical set- tings, sensor ranges, and jumper positions are also shown.
  • Page 50 Table 12 — EconoMi$er IV Input/Output Logic INPUTS OUTPUTS Demand Enthalpy Compressor N Terminal Controlled Ventilation Outdoor Return Stage 1 Stage 2 Occupied Unoccupied (DCV) High (Free Cooling Minimum position Closed Below Set LED Off) (DCV LED Modulating (between Modulating (between Off) min.
  • Page 51 Outdoor Air Lockout Sensor DIP Switch Changeover The EconoMi$er IV is equipped with an ambient temperature Position Temperature lockout switch located in the outdoor airstream which is used to lock out the compressors below a 42°F (6°C) ambient tem- 48°F perature.
  • Page 52 (29) (32) (35) (38) (41) (43) 48FC-20-30 – Economizer Pressure Drop CONTROL POINT CONTROL APPROX. °F (°C) CURVE 0.12 AT 50% RH (27) 73 (23) 70 (21) 0.10 67 (19) 63 (17) 0.08 (24) 0.06 (21) 0.04 0.02 (18) 0.00 3000 5000 7000...
  • Page 53 Exhaust Set Point Adjustment Damper Movement The exhaust set point will determine when the exhaust fan runs Damper movement from full open to full closed (or vice versa) based on damper position (if accessory power exhaust is in- takes 2-1/2 minutes. stalled).
  • Page 54 IV preparation procedure has selected anytime after the sensor is powered up. been performed. Use setting 1 or 2 for Carrier equipment Place 620-ohm resistor across SO and +. Press Clear and Mode buttons. Hold at least 5 seconds until Place 1.2 kilo-ohm resistor across SR and +.

  • Page 55: Economi$Er X (Factory-Installed Option)

    DCV MINIMUM AND MAXIMUM POSITION EconoMi$er X (Factory-Installed Option) To check the DCV minimum and maximum position: PRODUCT DESCRIPTION Make sure EconoMi$er IV preparation procedure has been The EconoMi$er ® X system is an expandable economizer control performed. system, which includes a W7220 economizer module (controller) Connect a 9-v battery to AQ (positive node) and AQ1 (neg- with an LCD and keypad (see Fig.
  • Page 56 SPECIFICATIONS OUTPUTS W7220 Economizer Module Actuator Signal: The module is designed for use with 2 to 10 vdc or bus communi- 2-10 vdc; minimum actuator impedance is 2k ohm; bus two-wire cating actuator. The module includes terminals for CO sensor, output for bus communicating actuators.
  • Page 57 Table 14 — Economizer Module — Left Hand Terminal Blocks LABEL TYPE DESCRIPTION Top Left Terminal Block 20k NTC and Mixed Air Temperature Sensor (Polarity Insensitive Connection) 20k NTC and Outdoor Air Temperature Sensor (Polarity Insensitive Connection) S-BUS S-BUS Enthalpy Control Sensor S-BUS (Sylk™...
  • Page 58 To use the keypad when working with Set Points, System and Ad- CO Sensor vanced Settings, Checkout tests and Alarms: Navigate to the desired menu. Press the (Enter) button to display the first item in the (Hot) Black currently displayed menu. Use the ▲...
  • Page 59 Table 18 — W7220 Menu Structure PARAMETER PARAMETER MENU PARAMETER DEFAULT RANGE AND NOTES VALUE INCREMENT FIRST STAGE COOLING DEMAND (Y1–IN) ECONO AVAIL YES/NO YES = economizing available; the system can use outside air for free cooling when required. FIRST STAGE COOLING RELAY OUTPUT ECONOMIZING YES/NO YES = outside air being used for 1 stage cooling...
  • Page 60 Table 18 — W7220 Menu Structure (cont) PARAMETER PARAMETER MENU PARAMETER DEFAULT RANGE AND NOTES VALUE INCREMENT MECH COOL ON Displays stage of mechanical cooling that is active. 0, 1, or 2 HEAT STAGES ON Displays the stage of heat pump heating that is active. STATUS SUPPLY FAN SPEED (cont)
  • Page 61 Table 18 — W7220 Menu Structure (cont) PARAMETER PARAMETER MENU PARAMETER DEFAULT RANGE AND NOTES VALUE INCREMENT 0°F to 50°F ENERGY RECOVERY VENTILATOR UNIT OUTDOOR AIR ERV OAT SP 32°F (–18°C to 10°C); TEMPERATURE SETPOINT increment by 1°F Only displayed when AUX1 O = ERV. Exhaust fan set point for single speed units.
  • Page 62 Table 18 — W7220 Menu Structure (cont) PARAMETER PARAMETER MENU PARAMETER DEFAULT RANGE AND NOTES VALUE INCREMENT COOLING STAGE 3 DELAY 0 min, 5 min, Delay after stage 2 cool has been active. Turns on second stage of 15 min, then cooling when economizer is first stage and mechanical cooling is STG3 DLY 2.0h...
  • Page 63 Table 18 — W7220 Menu Structure (cont) PARAMETER PARAMETER MENU PARAMETER DEFAULT RANGE AND NOTES VALUE INCREMENT DISCHARGE AIR S-BUS SENSOR ERROR DA SYLK T ERR Discharge air sensor has failed or become disconnected - check wiring then replace sensor if the alarm continues. OUTSIDE AIR TEMPERATURE SENSOR ERROR OA SENS T ERR Outdoor air temperature sensor has failed or become disconnected...
  • Page 64 2 SPEED FAN OPERATION The 2 speed fan delay is available when the system is programmed for 2 speed fan (in the System Setup menu item). The 2 speed fan The W7220 controller has the capability to work with a system us- delay is defaulted to 5 minutes and can be changed in the Ad- ing a 2-speed supply fan.
  • Page 65 ENTHALPY SETTINGS When all of the OA conditions are above the selected bound- ary, the conditions are not good to economize and the mode is When the OA temperature, enthalpy and dew point are below set to NO. the respective set points, the Outdoor Air can be used for econ- Figure 79 shows the 5 current boundaries.

  • Page 66: Pre-Start-Up/Start-Up

    CHECKOUT TROUBLESHOOTING Inspect all wiring connections at the economizer module’s termi- Alarms nals, and verify compliance with the installation wiring diagrams. The economizer module provides alarm messages that display For checkout, review the Status of each configured parameter and on the 2-line LCD. perform the Checkout tests.

  • Page 67: Start-Up, General

    Gas Piping Check gas piping for leaks. WARNING ELECTRICAL OPERATION HAZARD WARNING Failure to follow this warning could result in personal injury or death. FIRE, EXPLOSION HAZARD The unit must be electrically grounded in accordance with lo- Failure to follow this warning could result in death, serious cal codes and NEC ANSI/NFPA 70 (American National Stan- personal injury and/or property damage.

  • Page 68: Outdoor-Air Inlet Screens

    Outdoor-Air Inlet Screens Main Burner Outdoor-air inlet screen must be in place before operating unit. Main burners are factory set and should require no adjustment. To check ignition of main burners and heating controls, move Compressor Mounting thermostat setpoint above room temperature and verify that the Compressors are internally spring mounted.

  • Page 69: Fastener Torque Values

    FASTENER TORQUE VALUES START-UP, SYSTEMVU CONTROLS Table 22 — Torque Values IMPORTANT: SET-UP INSTRUCTIONS Installation, wiring and troubleshooting information for the Stator Motor Mounting 50 in.-lb (5.7 Nm) + 5 in.-lb (0.6 Nm) Screws SystemVu™ Controller.: “48/50FC04-30, 48/50GC04-06 Single Package Rooftop Units with SystemVu Controls Fan Rotor Mounting 50 in.-lb (5.7 Nm) + 5 in.-lb (0.6 Nm) Screws (2.4 HP)

  • Page 70: Appendix A - Model Number Nomenclature

    APPENDIX A — MODEL NUMBER NOMENCLATURE Position: 9 10 11 12 13 14 15 16 17 18 Example: Unit Heat Type Packaging Compliance 48 — Gas Heat Packaged Rooftop 0 = Standard Model Series - WeatherMaker ® Electrical Options FC — Standard Efficiency (EcoBlue™ Technology) A = None C = Non-Fused Disconnect D = Thru-the-Base Connections...
  • Page 71 APPENDIX B — PHYSICAL DATA 48FC*(M/N) 20 to 24 — Physical Data UNIT 48FC*M20 48FC*N20 48FC*M24 48FC*N24 NOMINAL CAPACITY (tons) 17.5 17.5 BASE UNIT OPERATING WT (lb) 48FC 1800 1800 2000 2000 REFRIGERATION SYSTEM Number Circuits / Number Compressors / Type 1 / 2 / Scroll 1 / 2 / Scroll 1 / 2 / Scroll...
  • Page 72 APPENDIX B — PHYSICAL DATA (cont) 48FC*(M/N) 28 to 30 — Physical Data UNIT 48FC*M28 48FC*N28 48FC*M30 48FC*N30 NOMINAL CAPACITY (tons) 27.5 27.5 BASE UNIT OPERATING WT (lb) 48FC 2174 2174 2351 2351 REFRIGERATION SYSTEM Number Circuits / Number Compressors / Type 1 / 2 / Scroll 1 / 2 / Scroll 1 / 2 / Scroll...
  • Page 73 APPENDIX C — GAS HEAT DATA 48FC 20 to 30 Gas Heat Data UNIT 48FC**20 48FC**24 48FC**28 48FC**30 NOMINAL CAPACITY (tons) 17.5 27.5 GAS CONNECTION Number of Gas Valves Natural Gas Supply Line Pressure (in. wg)/(psig) 5-13 / 0.18-0.47 5-13 / 0.18-0.47 5-13 / 0.18-0.47 5-13 / 0.18-0.47 Liquid Propane Supply Line Pressure (in.

  • Page 74: General Fan Performance Notes

    APPENDIX D — FAN PERFORMANCE For information on the electrical properties of the fan GENERAL FAN PERFORMANCE NOTES motors, please see the Electrical information section of Interpolation is permissible. Do not extrapolate. this book. External static pressure is the static pressure difference For more information on the performance limits of the fan between the return duct and the supply duct plus the static motors, see the application data section of this book.
  • Page 75 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM20 — 17.5 Ton Vertical Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 5250 1099 1.00 1210 1.33 1313 1.70 1408 2.10 1496 2.51 5690 1172 1.21 1276 1.56 1375 1.96 1466 2.37 1551 2.81...
  • Page 76 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM20 – High Static — 17.5 Ton Vertical Supply (rpm - vdc) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 5250 1099 1210 1313 1408 1496 5690 1172 1276 1375 1466 1551 6125 1247 1344 1438 1525 1607 6565...
  • Page 77 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM24 — 20 Ton Vertical Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 6000 1225 1.38 1325 1.75 1419 2.15 1508 2.58 1591 3.03 6500 1312 1.69 1403 2.07 1493 2.50 1578 2.95 1658 3.42...
  • Page 78 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM24 – High Static — 20 Ton Vertical Supply (rpm - vdc) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 6000 1225 1325 1419 1508 1591 6500 1312 1403 1493 1578 1658 7000 1399 1484 1568 1649 1726 7500...
  • Page 79 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM28 — 25 Ton Vertical Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 7500 1184 1.59 1267 1.95 1355 2.39 1444 2.89 1531 3.44 8125 1270 1.98 1345 2.35 1425 2.80 1507 3.31 1590 3.89...
  • Page 80 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM28 – High Static — 25 Ton Vertical Supply (rpm - vdc) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 7500 1184 1267 1355 1444 1531 8125 1270 1345 1425 1507 1590 8750 1357 1425 1498 1574 1651 9375...
  • Page 81 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM30 — 27.5 Ton Vertical Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 8250 1280 2.03 1353 2.40 1431 2.84 1512 3.35 1593 3.91 8940 1376 2.53 1442 2.91 1513 3.36 1586 3.88 1661 4.45...
  • Page 82 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM30 – High Static — 27.5 Ton Vertical Supply (rpm - vdc) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 8250 1280 1353 1431 1512 1593 8940 1376 1442 1513 1586 1661 9625 1472 1533 1597 1664 1733 10300...
  • Page 83 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM20 — 17.5 Ton Horizontal Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 5250 1237 1.14 1337 1.43 1432 1.76 1522 2.11 1607 2.49 5690 1323 1.38 1417 1.69 1506 2.03 1592 2.40 1673 2.79...
  • Page 84 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM24 — 20 Ton Horizontal Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 6000 1386 1.58 1475 1.90 1561 2.25 1643 2.62 1722 3.02 6500 1487 1.92 1570 2.26 1650 2.62 1728 3.01 1803 3.42...
  • Page 85 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM28 — 25 Ton Horizontal Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 7500 1494 2.53 1571 2.94 1648 3.39 1722 3.87 1795 4.38 8125 1606 3.13 1678 3.57 1748 4.04 1818 4.54 1886 5.07...
  • Page 86 APPENDIX D — FAN PERFORMANCE (cont) 48FCFM30 — 27.5 Ton Horizontal Supply (rpm - bhp) AVAILABLE EXTERNAL STATIC PRESSURE (in. wg) 8250 1619 3.20 1689 3.64 1759 4.11 1828 4.61 1896 5.15 8940 1743 3.97 1808 4.43 1872 4.91 1936 5.44 2000 5.99...
  • Page 87 APPENDIX E — WIRING DIAGRAMS 48FC*20-30 — Wiring Diagrams — Standard SCCR CONTROL SIZE VOLTAGE PAGE POWER PAGE (OVERLAY) 208/230 50HE003741 50HE003743 48FC*20-28 Electro-Mechanical 50HE003762 50HE003742 W7220 Controller 50HE003763 208/230 50HE003741 50HE003744 48FC*30 Electro-Mechanical 50HE003764 50HE003742 W7220 Controller 50HE003765 48FC*20-28 208/230 50HE004108 50HE004092...
  • Page 88 APPENDIX E — WIRING DIAGRAMS (cont) Fig. B — 48FC**20-30 — 208/230-3-60 — Control Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 89 APPENDIX E — WIRING DIAGRAMS (cont) Fig. C — 48FC**20-30 — 460/575-3-60 — Control Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 90 APPENDIX E — WIRING DIAGRAMS (cont) Fig. D — 48FC**20-30 — 208/230-3-60 — Control Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 91 APPENDIX E — WIRING DIAGRAMS (cont) Fig. E — 48FC**20-30 — 460/575-3-60 — Control Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 92 APPENDIX E — WIRING DIAGRAMS (cont) Fig. F — 48FC**20-28 — 208/230-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 93 APPENDIX E — WIRING DIAGRAMS (cont) Fig. G — 48FC**20-28 — 460-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 94 APPENDIX E — WIRING DIAGRAMS (cont) Fig. H — 48FC**20-28 — 575-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 95 APPENDIX E — WIRING DIAGRAMS (cont) Fig. I — 48FC**30 — 208/230-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 96 APPENDIX E — WIRING DIAGRAMS (cont) Fig. J — 48FC**30 — 460-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 97 APPENDIX E — WIRING DIAGRAMS (cont) Fig. K — 48FC**30 — 575-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — SCCR...
  • Page 98 APPENDIX E — WIRING DIAGRAMS (cont) Fig. L — 48FC**20-28 — 208/230-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 99 APPENDIX E — WIRING DIAGRAMS (cont) Fig. M — 48FC**20-28 — 460-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 100 APPENDIX E — WIRING DIAGRAMS (cont) Fig. N — 48FC**20-28 — 575-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 101 APPENDIX E — WIRING DIAGRAMS (cont) Fig. O — 48FC**30 — 208/230-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 102 APPENDIX E — WIRING DIAGRAMS (cont) Fig. P — 48FC**30 — 460-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 103 APPENDIX E — WIRING DIAGRAMS (cont) Fig. Q — 48FC**30 — 575-3-60 — Power Wiring Diagram with SystemVu™ Controller — SCCR...
  • Page 104 APPENDIX E — WIRING DIAGRAMS (cont) Fig. R — 48FC**20-30 — 208/230-3-60 — Control Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 105 APPENDIX E — WIRING DIAGRAMS (cont) Fig. S — 48FC**20-30 — 460/575-3-60 — Control Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 106 APPENDIX E — WIRING DIAGRAMS (cont) Fig. T — 48FC**20-30 — 208/230-3-60 — Control Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 107 APPENDIX E — WIRING DIAGRAMS (cont) Fig. U — 48FC**20-30 — 460/575-3-60 — Control Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 108 APPENDIX E — WIRING DIAGRAMS (cont) Fig. V — 48FC**20-28 — 208/230-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 109 APPENDIX E — WIRING DIAGRAMS (cont) Fig. W — 48FC**20-28 — 460-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 110 APPENDIX E — WIRING DIAGRAMS (cont) Fig. X — 48FC**30 — 208/230-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 111 APPENDIX E — WIRING DIAGRAMS (cont) Fig. Y — 48FC**30— 460-3-60 — Power Wiring Diagram Electro-Mechanical with W7220 Controller — HSCCR...
  • Page 112 APPENDIX E — WIRING DIAGRAMS (cont) Fig. Z — 48FC**20-28 — 208/230-3-60 — Power Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 113 APPENDIX E — WIRING DIAGRAMS (cont) Fig. AA — 48FC**20-28 — 460-3-60 — Power Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 114 APPENDIX E — WIRING DIAGRAMS (cont) Fig. AB — 48FC**30 — 208/230-3-60 — Power Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 115 APPENDIX E — WIRING DIAGRAMS (cont) Fig. AC — 48FC**30 — 460-3-60 — Power Wiring Diagram with SystemVu™ Controller — HSCCR...
  • Page 116 APPENDIX F — LOW AMBIENT CONTROL SENSOR LOCATION T O P O F C O I L T O P O F C O I L S E N S O R P O S I T I O N S E E N O T E # 1 S E N S O R P O S I T I O N S E E N O T E # 1...
  • Page 118 © 2024 Carrier Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-53480333-01 Printed in U.S.A. Form 48FC-20-30-01SM Pg 118 1-24 Replaces: NEW...
  • Page 119 START-UP CHECKLIST 48FC**20-30 Single Package Rooftop Gas Heat/Electric Cooling Unit (Remove and use for job file) NOTE: To avoid injury to personnel and damage to equipment or property when completing the procedures listed in this start-up checklist, use good judgment, follow safe practices, and adhere to the safety considerations/information as outlined in preceding sections of this Service and Maintenance Instruction document.
  • Page 120 5. Turn off heating, cooling, and reheat, restore set points for thermostat and humidistat (Y/N) _____ © 2024 Carrier Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-53480333-01 Printed in U.S.A.

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