| MAINTENANCE SERVICE AND ANALYSIS GUIDE | |||
MALFUNCTION | POSSIBLE CAUSE | SOLUTION | ||
Compressor will not start - | 1. | Service cord unplugged | 1. | Plug in service cord |
no hum | 2. | Fuse blown or removed | 2. | Replace fuse |
| 3. | Overload tripped | 3. | Determine reasons and correct |
| 4. | Control stuck open | 4. | Repair or replace |
| 5. | Wiring incorrect | 5. | Check wiring against the diagram |
Compressor will not start - | 1. | Improperly wired | 1. | Check wiring against the diagram |
hums but trips on overload | 2. | Low voltage to unit | 2. | Determine reason and correct |
protector | 3. | Starting capacitor defective | 3. | Determine reason and replace |
| 4. | Relay failing to close | 4. | Determine reason, correct or replace |
Compressor starts and runs, | 1. | Low voltage to unit | 1. | Determine reason and correct |
but short cycles on overload | 2. | Overload defective | 2. | Check current, replace overload protector |
protector | 3. | Excessive head pressure | 3. | Check ventilation or restriction in |
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| refrigeration system |
| 4. | Compressor | 4. | Check refrigerant charge, fix leak if necessary |
Compressor operates long | 1. | Short of refrigerant | 1. | Fix leak, add charge |
or continuously | 2. | Control contact stuck | 2. | Repair or replace |
| 3. | Evaporator coil iced | 3. | Determine cause, defrost manually |
| 4. | Restriction in refrigeration system 4. | Determine location and remove restriction | |
| 5. | Dirty condenser | 5. | Clean condenser |
| 6. | Location too warm | 6. | Ventilate area or change location. |
Compressor runs fine, but | 1. | Overload protector | 1. | Check wiring diagram |
short cycles | 2. | Cold control | 2. | Differential too close - widen |
| 3. | Overcharge | 3. | Reduce charge |
| 4. | Air in system | 4. | Purge and recharge |
| 5. | Undercharge | 5. | Fix leak, add refrigerant |
Starting capacitor open, | 1. Relay contacts stuck | 1. | Clean contacts or replace relay | |
shorted or blown | 2. | Low voltage to unit | 2. | Determine reason and correct |
| 3. | Improper relay | 3. | Replace |
Relay defective or burned out | 1. | Incorrect relay | 1. | Check and replace |
| 2. | Voltage too high or too low | 2. | Determine reason and correct |
Refrigerated space too warm | 1. | Control setting too high | 1. | Reset control |
| 2. | Refrigerant overcharge | 2. | Purge refrigerant |
| 3. | Dirty condenser | 3. | Clean condenser |
| 4. | Evaporator coil iced | 4. | Determine reason and defrost |
| 5. | Not operating | 5. | Determine reason, replace if necessary |
Objectionable noise | 1. | Fan blade hitting fan shroud | 1. | Reform or cut away small section of shroud |
| 2. | Tubing rattle | 2. | Locate and reform |
| 3. | Vibrating fan blade | 3. | Replace fan blade |
| 4. | Condenser fan motor rattles | 4. | Check motor bracket mounting, tighten |
| 5. | General vibration | 5. | Compressor suspension bolts not loosened |
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| on applicable models - loosen them |
| 6. | Worn fan motor bearings | 6. | Replace fan motor |
4 | 1/08 | N138647 |
