| Document type | Operation Guide |
|---|---|
| Document number | 160.54-O2 |
| Equipment | YK Centrifugal Chiller |
| Brand | YORK |
| Revised | 2025-04-25 |
| File size | 1.3 MB |
Fault codes in this document
Table 1 – Operation analysis chart
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Abnormally high discharge pressure | Temperature difference between condensing temperature and water off condenser higher than normal. | Air in condenser. | 23 | |
| Abnormally high discharge pressure | High discharge pressure. | Condenser tubes dirty or scaled | Clean condenser tubes. Check water conditioning. | 23 |
| Abnormally high discharge pressure | High condenser water temperature. | Reduce condenser water inlet temperature. (Check cooling tower and water circulation.) | 23 | |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in evaporator greater than normal with high discharge temperature. | Insufficient charge of refrigerant in evaporator | Check for leaks and charge refrigerant into system. | 23 |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in evaporator greater than normal with high discharge temperature. | Variable orifice problem. | Remove obstruction. | 23 |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in the evaporator greater than normal with normal discharge temperature. | Evaporator tubes dirty or restricted. | Clean evaporator tubes. | 23 |
| Abnormally low suction pressure | Temperature of chilled water too low with low motor amperes. | Insufficient load for system capacity. | Check prerotation vane motor operation and setting of low water temperature cutout. | 23 |
| High evaporator pressure | High chilled water temperature. | Prerotation vanes fail to open. | Check the prerotation vane motor positioning circuit. | 23 |
| High evaporator pressure | System overload. | Be sure the vanes are wide open (without overloading the motor) until the load decreases. | 23 | |
| No oil pressure when the SYSTEM START button is pressed | Low oil pressure displayed on control center; compressor does not start. | Oil pump running in wrong direction. | Check rotation of oil pump (Electrical Connections). | 23 |
| No oil pressure when the SYSTEM START button is pressed | Low oil pressure displayed on control center; compressor does not start. | Oil pump not running. | Troubleshoot electrical problem with oil pump VSD. | 23 |
| Unusually high oil pressure develops when the 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 transducer defective. | Replace low or high oil pressure transducer. | 24 |
| Oil pump vibrates or is too noisy | Oil pump vibrates or is extremely noisy with some oil pressure when pressing OIL PRESSURE display key. | Oil not reaching pump suction inlet in sufficient quantity. | Check oil level. | 24 |
| Oil pump vibrates or is too noisy | When the oil pump is run without an oil supply it vibrates and becomes extremely noisy. | Worn or failed oil pump. | Repair/Replace oil pump. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Excessive end clearance pump. | Inspect and replace worn parts. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Other worn pump parts. | Inspect and replace worn parts. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Partially blocked oil supply inlet. | Check oil inlet for blockage. | 24 |
| Oil pressure gradually decreases (Noted by Observation of Daily Log Sheets) | When oil pump VSD frequency increases to 55 + hz to maintain target oil pressure. | Oil filter is dirty. | Change oil filter. | 24 |
| Oil pressure 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. | 24 |
| Oil pressure system ceases to return an oil or refrigerant sample | Jet or orifice of oil return jet clogged. | Remove jet, inspect for dirt. Remove dirt using solvent and replace. | 24 | |
| Oil pump fails to deliver oil pressure | No oil pressure registers when pressing OIL PRESSURE display key when oil pump runs. | Faulty oil pressure transducer | Replace oil pressure transducer. | 24 |
| Oil pump fails to deliver oil pressure | No oil pressure registers when pressing OIL PRESSURE display key when oil pump runs. | Faulty wiring/connectors. | 24 |
Every row above cites the page of this document it came from, and each one is re-read against that page by an automatic check before publication.
Manufacturer document, published here as reference material for equipment we supply. The original lives at docs.johnsoncontrols.com. The rights holder may ask us to take it down — we will.