Carrier 50JZ024 Installation, Start-up And Service Instructions Manual

Also see for 50JZ024: Installation and operating instructions Guide to operating and maintaining Guide to operating and maintaining Product data Product data

Contents

Troubleshooting ChartSYMPTOM CAUSE REMEDYCompressor and outdoor fan will not startPower failure Call power companyFuse blown or circuit breaker tripped Replace fuse or reset circuit breakerDefective thermostat, contactor, transformer, con-trol relay, defrost board, or high pressure or loss-of-charge/low pressure switchReplace componentInsufficient line voltage Determine cause and correctIncorrect or faulty wiring Check wiring diagram and rewire correctlyThermostat setting too high Lower thermostat setting below room tempera-tureUnits have a 5-minute time delayDO NOT bypass this compressor timedelay—wait for 5 minutes until time-delay relay isdeenergizedCompressor will not start but condenser fanrunsFaulty wiring or loose connections in compressorcircuit Check wiring and repair or replaceCompressor motor burned out, seized, or internaloverload openDetermine causeReplace compressorDefective run capacitor, overload, or PTC (posi-tive temperature coefficient) thermistor Determine cause and replaceOne leg of 3-phase power dead Replace fuse or reset circuit breaker DeterminecauseLow input voltage (20% low) Determine cause and correctThree-phase scroll compressor (size 030-060units) may be a low pressure differentialScroll compressor is rotating in the wrong direc-tionCorrect the direction of rotation by reversing the3-phase power leads to the unitCompressor cycles (other than normally sat-isfying thermostat)Refrigerant overcharge or undercharge Recover refrigerant, evacuate system, and re-charge to capacities shown on nameplateDefective compressor Replace and determine causeInsufficient line voltage Determine cause and correctBlocked outdoor coil Determine cause and correctDefective run/start capacitor, overload or startrelay Determine cause and replaceDefective thermostat Replace thermostatFaulty outdoor-fan motor or capacitor ReplaceDamaged reversing valve Determine cause and correctRestriction in refrigerant system Locate restriction and removeCompressor operates continuouslyDirty air filter Replace filterUnit undersized for load Decrease load or increase unit sizeThermostat set too low Reset thermostatLow refrigerant charge Locate leak, repair, and rechargeFrosted coil with incorrect defrost operationCheck defrost time settingsReset as necessaryCheck defrost temperature switchReplace as necessaryAir in system Recover refrigerant, evacuate system, and re-chargeOutdoor coil dirty or restricted Clean coil or remove restrictionExcessive head pressureDirty air filter Replace filterDirty indoor or outdoor coil Clean coilRefrigerant overcharged Recover excess refrigerantAir in system Recover refrigerant, evacuate system, and re-charge(Heat) Indoor air restricted or recirculating Determine cause and correctIndoor or outdoor air restricted or air short-cycling Determine cause and correctHead pressure too low Low refrigerant charge Check for leaks, repair and rechargeRestriction in liquid tube Remove restrictionExcessive suction pressure(Heat) Outdoor coil frosted Move timer on control board to 30 minutes be-tween defrost cycles(Cool) High Heat load Check for source and eliminateReversing valve hung up or leaking internally Replace valveRefrigerant overcharged Recover excess refrigerant24