30Table 10 – Troubleshooting ChartSYMPTOM CAUSE REMEDYCompressor and condenser fan will not start.Power failure Call power companyFuse blown or circuit breaker tripped Replace fuse or reset circuit breakerDefective contactor, transformer, or high--pressure,loss--of--charge or low--pressure switch Replace 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-tureCompressor will not start but condenser fanrunsFaulty wiring or loose connections in compressor cir-cuit Check wiring and repair or replaceCompressor motor burned out, seized, or Determine causeinternal overload open Replace compressorDefective run/start capacitor, overload, start relay Determine cause and replaceOne leg of 3--phase power dead Replace fuse or reset circuit breakerDetermine causeThree--phase scroll compressorScroll compressor is rotating in the wrong direction Correct the direction of rotation by reversing the3--phase power leads to the unit.makes excessive noise, and there may be alow pressure differential.Compressor cycles (other than normally sat-isfying thermostat).Refrigerant overcharge or undercharge Recover refrigerant, evacuate system, and re-charge to capacities shown on rating plateDefective compressor Replace and determine causeInsufficient line voltage Determine cause and correctBlocked condenser Determine cause and correctDefective run/start capacitor, overload or start relay Determine cause and replaceDefective thermostat Replace thermostatFaulty condenser--fan motor or capacitor ReplaceRestriction 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 rechargeMechanical damage in compressor Replace compressorAir in system Recover refrigerant, evacuate system, and re-chargeCondenser coil dirty or restricted Clean coil or remove restrictionExcessive head pressureDirty air filter Replace filterDirty condenser coil Clean coilRefrigerant overcharged Recover excess refrigerantAir in system Recover refrigerant, evacuate system, and re-chargeCondenser air restricted or air short--cycling Determine cause and correctHead pressure too lowLow refrigerant charge Check for leaks, repair, and recharge.Compressor IPR leaking Replace compressorRestriction in liquid tube Remove restrictionExcessive suction pressureHigh heat load Check for source and eliminateCompressor IPR leaking Replace compressorRefrigerant overcharged Recover excess refrigerantSuction pressure too lowDirty air filter Replace filterLow refrigerant charge Check for leaks, repair and rechargeMetering device or low side restricted Remove source of restrictionInsufficient evaporator airflow Increase air quantityCheck filter–replace if necessaryTemperature too low in conditioned area Reset thermostatOutdoor ambient below 55°F (12.7°C) Install low--ambient kitFilter drier restricted Replace filter50VT-- A