Carrier Split Systems and Condensers 38AP

Check all electrical connections, tighten as necessary.

Inspect all contactors and relays, replace as necessary.

Check accuracy of thermistors, replace if greater than ± 2°F (1.2°C) variance from calibrated thermometer.

Check accuracy of transducers, replace if greater than ± 5 psig (35 kPa) variance from calibrated gauge.

Obtain and test an oil sample. Change oil only if necessary.

Check refrigerant filter driers for excessive pressure drop, replace as necessary.

Check condition of condenser fan blades and ensure they are securely fastened to the motor shaft.

Lubricate fan shaft with rust inhibitor, propeller-style (metal) or AeroAcoustic fans with gray bolt, if necessary.

Check condenser coils for debris, clean as necessary.

Check moisture indicating sight glass for possible refrigerant loss and presence of moisture.

Check fusible plugs to be sure that they have not been capped. If the fusible plugs are vented, be sure the vent line is free of any obstructions.

For units with High Efficiency Variable Condenser Fan option, check the VFD fan inlet for debris, snow, or ice. Clean as necessary.

Select the type of condenser fan

If Propeller (Metal) Fan and AeroAcoustic Fan with Gray Bolt is selected, apply Tectyl 506G (Ashland Petroleum Company) grease to the fan shaft and hub.

AeroAcoustic Fan with Black Bolt

This assembly uses Loctite 680 Retaining Compound. DO NOT lubricate the fan shaft or fan hub.

The condenser fan motors have sealed bearings so no field lubrication is required.

All door hinges should be lubricated at least once a year.

Check all refrigerant joints and valves for refrigerant leaks, repair as necessary.

Check fan status switch operation.

Check condenser coils for debris.

Check all condenser fans for proper operation.

Check crankcase heater operation.

For units with High Efficiency Variable Condenser Fan option, check the VFD fan filter. Clean if necessary.

WARNING: Do not supply power to unit with compressor cover removed. Failure to follow this warning can cause a fire, resulting in personal injury or death.

WARNING: Exercise extreme caution when reading compressor currents when high-voltage power is on. Correct any of the problems described below before installing and running a replacement compressor. Wear safety glasses and gloves when handling refrigerants. Failure to follow this warning can cause fire, resulting in personal injury or death.

CAUTION: Do not manually operate contactors. Serious damage to the machine may result.

Proper voltage to the unit should be verified.

The normal checks of motor winding continuity and short to ground should be made to determine if the inherent overload motor protector has opened or if an internal motor short or ground fault has developed. If the protector has opened, the compressor must be allowed to cool sufficiently to allow it to reset.

Proper indoor and outdoor blower/fan operation should be verified.

With service gages connected to suction and discharge pressure fittings, turn on the compressor. If suction pressure falls below normal levels, the system is either low on charge or there is a flow blockage in the system.

If suction pressure does not drop and discharge pressure does not rise to normal levels, reverse any two of the compressor power leads and reapply power to make sure compressor was not wired to run in reverse direction. If pressures still do not move to normal values, the compressor may be faulty. Reconnect the compressor leads as originally configured.

To test if the compressor is pumping properly, the compressor current draw must be compared to published compressor performance curves using the operating pressures and voltage of the system. If the measured average current deviates more than ±15% from published values, a faulty compressor may be indicated. A current imbalance exceeding 15% of the average on the three phases should be investigated further.