TROUBLESHOOTING (cont)
| PROBLEM |
| SOLUTION |
COMPRESSOR STOPS ON OIL PRESSURE SWITCH |
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1. | Oil level too low or too high. | 1. | Check oil level requirements; adjust oil level until sight |
2. Compressor is short cycling. |
| glass is ®lled1¤8 to 1¤3 when running. | |
2. | Check for | ||
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| a) Thermostat location and operation. |
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| b) Safety device lockout circuit operation. |
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| c) |
3. | Crankcase heater off. |
| d) |
3. | Check relay operation; replace crankcase heater(s), if | ||
4. | Low refrigerant charge. |
| defective. |
4. | Adjust charge as required. | ||
5. Refrigerant ¯oodback. | 5. | Adjust TXV superheat. | |
6. | Evaporator coil is blocked or iced. | 6. | Check and correct as required. |
7. | Evaporator fan not operating. | 7. | Check and correct as required. |
8. | Distributor and/or TXV too large. | 8. | Check sizing at design conditions; change if incorrect |
9. | Suction riser too large. |
| for current application. |
9. | Check line sizing at minimum design condition; change | ||
10. | Defective oil pressure switch. |
| piping if incorrect. |
10. | Check switch for proper operation; check capillary lines | ||
11. Plugged oil pump inlet screen. |
| for plugged lines. | |
11. | Clean oil pump screen. | ||
12. Faulty oil pump drive segment. | 12. | Replace drive segment. | |
13. Worn oil pump. | 13. | Replace bearing head assembly. | |
14. Worn compressor bearings. | 14. | Replace compressor; see 06E service instructions. | |
COMPRESSOR RUNNING BUT COOLING INSUFFICIENT |
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Suction Pressure Low |
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1. | Refrigerant charge low. | 1. | Add refrigerant. |
2. | Head pressure low. | 2. | Check refrigerant charge. |
3. | Air ®lters dirty. |
| Check |
3. | Clean or replace ®lters. | ||
4. | Expansion valve power head defective. | 4. | Replace power head. |
5. | Indoor coil partially iced. | 5. | Check |
6. | Indoor air¯ow restricted. | 6. | Remove obstruction. |
Suction Pressure High |
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1. | Unloaders not functioning. | 1. | Check unloader adjustments. |
2. | Compressor valve defective. |
| Check unloader setting. |
2. | See 06E compressor service literature. | ||
3. | Heat load excessive. | 3. | Check for open doors or windows in vicinity of fan coil. |
UNIT OPERATES TOO LONG OR CONTINUOUSLY |
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1. | Low refrigerant charge. | 1. | Add refrigerant. |
2. | Control contacts fused. | 2. | Replace control. |
3. | Air in system. | 3. | Purge and evacuate system. |
4. | Partially plugged expansion valve or ®lter drier. | 4. | Clean or replace. |
SYSTEM IS NOISY |
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1. | Piping vibration. | 1. | Support piping as required. |
2. | Compressor noisy. | 2. | Check valve plates for valve noise. Replace compressor |
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| if bearings are worn. |
COMPRESSOR LOSES OIL |
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1. | Leak in system. | 1. | Repair leak. |
2. | Crankcase heaters not energized during shutdown. | 2. | Check wiring and relays. Check heater and replace if |
3. | Improper interconnecting piping design. |
| defective. |
3. | Check piping for oil return. Replace if necessary. | ||
FROSTED SUCTION LINE |
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1. | Expansion valve admitting excess refrigerant. | 1. | Adjust expansion valve. |
HOT LIQUID LINE |
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1. | Shortage of refrigerant due to leak. | 1. | Repair leak and recharge. |
2. | Expansion valve opens too wide. | 2. | Adjust expansion valve. |
FROSTED LIQUID LINE |
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1. | Restricted ®lter drier. | 1. | Remove restriction or replace. |
COMPRESSOR WILL NOT UNLOAD |
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1. | Defective unloader. | 1. | Replace unloader. |
2. | Defective capacity control solenoid valve (if used). | 2. | Replace valve. |
3. | Miswired capacity control liquid line solenoid (if used). | 3. | Rewire correctly. |
4. | Weak, broken, or wrong valve body spring. | 4. | Replace spring. |
COMPRESSOR WILL NOT LOAD |
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1. | Miswired capacity control liquid line solenoid (if used). | 1. | Rewire correctly. |
2. | Defective capacity control solenoid valve (if used). | 2. | Replace valve. |
3. | Plugged strainer (high side). | 3. | Clean or replace strainer. |
4. | Stuck or damaged unloader piston or piston ring(s). | 4. | Clean or replace the necessary parts. |
Copyright 1998 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, speci®cations or designs without notice and without incurring obligations.
Book | 1 |
| PC 111 | Catalog No. | Printed in U.S.A. | Form | 54 | Replaces: | |
Tab | 3a |
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