Kelvinator R-404A, Installation Manual

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COMPRESSOR TROUBLESHOOTING GUIDE
MAINTENANCE & REPAIR 49
PROBLEMS & CAUSE REMEDY
Compressor won’t start—no hum.
1. Open line circuit. 1. Check wiring, fuses, receptacle.
2. Protector open. 2. Wait for reset - check current.
3. Control contacts open. 3. Check control; check pressures.
Compressor won’t start—hums intermittently (cycling on protector).
1. Improperly wired. 1. Check wiring against diagram.
2. Low line voltage. 2. Check main line voltage, determine location of voltage drop.
3. Open starting capacitor. 3. Replace starting capacitor.
4. Relay contacts not closing. 4. Check by operating manually. Replace relay if defective.
5. Open circuit in starting winding. 5. Check stator leads. If leads are all right, replace compressor.
6. High discharge pressure. 6. Eliminate cause of excessive pressure.
7. Tight compressor. 7. Check oil level-correct binding condition, if possible. If not, replace compressor.
8. Weak starting capacitor or one weak capacitor of a set. 8. Check oil level. Check binding. Replace compressor if necessary.
Compressor starts; motor will not get off starting winding.
1. Low line voltage. 1. Bring up voltage.
2. Improperly wired. 2. Check wiring against diagram.
3. Defective relay. 3. Check operation - replace relay if defective.
4. Discharge pressure too high. 4. Check ventilation, restrictions and overcharge.
5. Starting and running windings shorted. 5. Check resistances. Replace compressor if defective.
6. Starting capacitor weak or one of a set open. 6. Check capacitance - replace if defective.
7. High discharge pressure. 7. Condenser dirty.
8. Tight compressor. 8. Check oil level. Check binding. Replace compressor if necessary.
Compressor starts and runs, but cycles on protector.
1. Short cycling. 1. Reduce number of starts to 20 or less per hour.
2. Additional current passing through protector. 2. Check for added fan motors and pumps connected to wrong side of protector.
3. Suction pressure too high. 3. Check compressor for proper application.
4. Discharge pressure too high. 4. Check ventilation, restrictions and overcharge.
5. Starting and running windings shorted. 5. Check resistances. Replace compressor if defective.
6. Starting capacitor weak or one of a set open. 6. Check capacitance - replace if defective.
7. Inadequate motor cooling. 7. Correct cooling system.
8. Compressor tight. 8. Check oil level. Check for binding condition.
9. Unbalanced line (three-phase) 9. Check voltage of each phase. If not equal, correct condition of unbalance.
10. Discharge valve leaking or broken. 10. Replace valve plate.
Starting capacitors burn out.
1. Short cycling. 1. Reduce number of starts to 20 or less per hour.
2. Prolonged operation on starting winding. 2. Reduce starting load.
3. Relay contact sticking. 3. Clean contacts or replace relay.
4. Improper relay or incorrect relay setting. 4. Replace relay.
5. Improper capacitor. 5. Check parts list for proper capacitor rating—mfd. and voltage.
6. Capacitor voltage rating too low. 6. Check capacitors with recommended voltage rating.
7. Capacitor terminals shorted by water. 7. Install capacitors so terminals will not be wet.
Running capacitors burn out.
1. Excessive line voltage. 1. Reduce line voltage to not over 10% above rating of motor.
2. High line voltage and light load. 2. Reduce voltage if over 10% excessive.
3. Capacitor voltage rating too low. 3. Install capacitors with recommended voltage rating.
Relays burn out.
1. Low line voltage. 1. Increase voltage to not less than 10% under compressor motor rating.
2. Excessive line voltage. 2. Reduce voltage to maximum of 10% above motor rating.
3. Incorrect running capacitor. 3. Replace running capacitor with correct mfd. capacitance.
4. Short cycling. 4. Reduce number of starts per hour.
5. Relay vibrating. 5. Mount relay rigidly.
6. Incorrect relay. 6. Use relay recommended for specific motor compressor.
Dipping Cabinet 1298.02 2/3/03 1:15 PM Page 51