| Document type | Operation Guide |
|---|---|
| Document number | 160.96-O1 |
| Equipment | YK-CP Centrifugal Chiller |
| Brand | YORK |
| Revised | 2025-11-14 |
| File size | 8.2 MB |
Fault codes in this document
Functional identification
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| PAH | Pressure alarm high (alarm) | 21 | ||
| PAHH | Pressure alarm high (shutdown) | 21 | ||
| PAL | Pressure alarm low (alarm) | 21 | ||
| PALL | Pressure alarm low (shutdown) | 21 | ||
| PDAL | Oil differential pressure alarm low (alarm) | 21 | ||
| PDALL | Oil differential pressure alarm low (shutdown) | 21 | ||
| PDAH | Oil differential pressure alarm high (alarm) | 21 | ||
| PDAHH | Oil differential pressure alarm high (shutdown) | 21 | ||
| TAH | Temperature alarm high (alarm) | 21 | ||
| TAHH | Temperature alarm high (shutdown) | 21 | ||
| TAL | Temperature alarm low (alarm) | 21 | ||
| TALL | temperature alarm low (shutdown) | 21 | ||
| TDALL | Oil temperature alarm low (shutdown) | 21 | ||
| FSALL | Flow switch alarm low (shutdown) | 21 | ||
| XC | Stall control | 21 | ||
| ZC | Thrust control | 21 | ||
| ZAH/ZAL | Thrust bearing probe alarm high or low (alarm) | 21 | ||
| ZAHH/ZALL | Thrust bearing probe alarm high or low (shutdown) | 21 | ||
| HPCO | High pressure cutoff | 21 | ||
| LOP | Low oil pressure | 21 | ||
| EHOP | High oil pressure, economizer compressor | 21 | ||
| PHOP | High oil pressure, primary compressor | 21 |
Maintenance
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Quarterly maintenance warning item (OptiView) | Monthly items are still required and appear on OptiView as a quarterly maintenance warning item. | Perform the monthly maintenance requirements. | 28 | |
| High oil temperature (HOT) shutdown | Unit shutting down on high oil temperature. | Change the oil filter element. Examine the oil filter element for aluminum particles. Aluminum gas seal rings can contact the impeller and cause some aluminum particles to accumulate in the oil filter, especially during the initial start up and first several months of operation. If aluminum particles continue accumulating, contact Johnson Controls Service. | 33 | |
| Low oil pressure (OP) shutdown | Unit shutting down on low oil pressure. | Change the oil filter element. Examine the oil filter element for aluminum particles. Aluminum gas seal rings can contact the impeller and cause some aluminum particles to accumulate in the oil filter, especially during the initial start up and first several months of operation. If aluminum particles continue accumulating, contact Johnson Controls Service. | 33 | |
| Warning message to re-lubricate (OptiView panel) | Motor bearing relubrication (greasing) due. Current YORK OptiView panels provide a warning message to re-lubricate beginning at a programmed number of operating hours (the default value is 1000 hours). | Programmed number of operating hours reached (default value 1000 hours). | Address re-lubrication. At the programmed value plus 400 hours this feature shuts down the chiller if re-lubrication is not addressed. In plants where chillers run 24/7, there is more than 16 days of advance warning prior to shutting down the chiller. | 37 |
| Bearing temperature warning (above 149°F (65°C)) | If the temperature exceeds 149°F (65°C), a warning is issued; it is an indication that either the bearings are in need of lubrication or that something is wrong. If temperature reaches 158°F (70°C), it generally indicates some type of problem. | Bearings in need of lubrication, or something is wrong. | Operation should be checked. | 41 |
| Bearing RTD motor shutdown (194°F (90°C)) | Bearing RTDs are normally set to shut down the motors at 194°F (90°C); when this temperature is reached, the bearings most likely have already been compromised. | 39 |
Troubleshooting
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| 1. Issue: abnormally high discharge pressure | The temperature difference between the condensing temperature and water off condenser is higher than normal. | Air is in the condenser. | 42 | |
| The temperature difference between the condensing temperature and water off condenser is higher than normal. | Condenser tubes dirty or scaled. | Clean condenser tubes. Check water conditioning. | 42 | |
| High discharge pressure. High condenser water temperature. | Reduce condenser water inlet temperature. Check cooling tower and water circulation. | 42 | ||
| The temperature difference between condenser water on and water off is higher than normal, with normal evaporator pressure. | Insufficient condensing water flow. | Increase the quantity of water through the condenser to proper value. | 42 | |
| 2. Issue: abnormally low suction pressure | Insufficient charge of refrigerant. | Check for leaks and charge refrigerant into system. | 42 | |
| The temperature difference between the leaving chilled water and the refrigerant in the evaporator is greater than normal with high discharge temperature. | Variable orifice problem. | Remove obstruction. | 42 | |
| The temperature difference between the leaving chilled water and the refrigerant in the evaporator is greater than normal with normal discharge temperature. | Evaporator tubes dirty or restricted. | Clean evaporator tubes. | 42 | |
| The temperature of chilled water is too low with low motor amperes. | Insufficient load for system capacity. | Check the motor operation of the PRV and check the setting of the low water temperature cutout. | 42 | |
| 3. Issue: high evaporator pressure | PRVs fail to open. | Check the PRV motor positioning circuit. | 42 | |
| High chilled water temperature. | System overload. | Ensure the vanes are wide open (without overloading the motor) until the load decreases. | 42 | |
| 4. Issue: no oil pressure when system start button pushed | Low oil pressure is displayed on the control center; the compressor does not start. | Oil pump running in wrong direction. | Check rotation of oil pump (Electrical Connections). | 42 |
| Low oil pressure is displayed on the control center; the compressor does not start. | Oil pump not running. | Troubleshoot electrical problem with oil pump VSD. | 42 | |
| 5. Issue: unusually high oil pressure develops when oil pump runs | Unusually high oil pressure is displayed when the oil pressure display key is pressed when the oil pump is running. | High oil pressure. The transducer is defective. | Replace low or high oil pressure transducer. | 42 |
| 6. Issue: oil pump vibrates or is noisy | Oil pump vibrates or is extremely noisy with some oil pressure when pressing the Oil Pressure display key. Note: When the oil pump runs without an oil supply, it vibrates and becomes extremely noisy. | Oil not reaching pump suction inlet in sufficient quantity. | Check oil level. | 42 |
| Oil pump vibrates or is extremely noisy with some oil pressure when pressing the Oil Pressure display key. Note: When the oil pump runs without an oil supply, it vibrates and becomes extremely noisy. | Worn or failed oil pump. | Repair or, if necessary, replace the oil pump. | 42 | |
| 7. Issue: reduced oil pump capacity | Oil pump pumping capacity. | Excessive end clearance pump. Other worn pump parts. | Inspect and replace worn parts. | 42 |
| Oil pump pumping capacity. | The oil supply inlet is partially blocked. | Check the oil inlet for blockage. | 42 | |
| 8. Issue: oil pressure gradually decreases as noted by observation of daily log sheets | When the oil pump VSD frequency increases to 55 + Hz to maintain target oil pressure. | Oil filter is dirty. | Change oil filter. | 42 |
| 9. Issue: oil return system ceases to return an oil or refrigerant sample | Oil refrigerant return not functioning. | Filter-drier in oil return system dirty. | Replace old filter-drier with new. | 42 |
| Oil refrigerant return not functioning. | Jet or orifice of oil return jet clogged. | Remove jet, inspect for dirt. Remove dirt using solvent and replace. | 42 | |
| 10. Issue: oil pump fails to deliver oil pressure | No oil pressure registers when pressing the Oil Pressure display key when the oil pump runs. | Faulty oil pressure transducer. | Replace oil pressure transducer. | 43 |
| No oil pressure registers when pressing the Oil Pressure display key when the oil pump runs. | Faulty wiring or connectors. | 43 |
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