| Document type | Service Information Letter |
|---|---|
| Document number | SI0610 |
| Equipment | YK Centrifugal Chiller |
| Brand | YORK |
| Revised | 2025-11-19 |
| File size | 2.5 MB |
Fault codes in this document
Display messages
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| WARNING – PURGE – EQ LOW SUCTION TEMP | Auto reset warning. Starting with Y.OPT.01.14.308 it does not inhibit purge operation. | Set conditions are the same as the previous WARNING – PURGE – EQUALIZATION LOW SUCTION TEMP. | Auto reset. | 13 |
| WARNING – PURGE – EQ LOW SUCTION TEMP INHIBIT | Manual reset warning. Inhibits purge operation. | Set when the WARNING – PURGE – EQ LOW SUCTION TEMP has been set 3 times in 1 hour. | Manual reset. | 13 |
| WARNING – PURGE – LOW COIL TEMP INHIBIT | Manual reset warning. Inhibits purge operation. | Purge coil temperature is less than -35°F. | Inhibits purge operation until the coil temperature is over -35°F and the Warning Reset key is pressed. | 13 |
| UPS – PERFORM BATTERY HEALTH CHECK | Start inhibit. | Set when the chiller shuts down on a MBC – POWER FAIL LANDING event. | The Battery Health Check must pass in order to clear the Power Failing fault. | 13 |
| OIL – HIGH VISCOSITY | Immediate safety fault. Only applies when the Oil Quality Protection AND Oil Cooling control are enabled. | Chiller has been running for 30 minutes and the Oil Kinematic Viscosity has been greater than the JCI Service programmable High Viscosity Trip Threshold (default is 30.0 cSt) for 5 minutes. | Fault can be cleared after the chiller has stopped and the Clear Fault key is selected. | 13 |
| OIL – LOW VISCOSITY | Safety fault. Only applies when the Oil Quality Protection AND Oil Cooling control are enabled. | Chiller has been running for 10 minutes and the Oil Kinematic Viscosity has been less than the JCI Service programmable Low Viscosity Trip Threshold Long Trip (default is 8.0 cSt) for 5 minutes; or the chiller has been running for 1 minute and the Oil Kinematic Viscosity has been less than the JCI Service programmable Low Viscosity Trip Threshold Short Trip (default is 6.0 cSt) for 10 seconds. | Fault can be cleared after the chiller has stopped and the Clear Fault key is selected. | 13 |
| OIL – HIGH DILUTION | Safety fault. Only applies when the Oil Quality Protection is enabled. | Chiller has been running for 10 minutes and the Oil Dilution is greater than the JCI Service programmable High Dilution Safety Trip Threshold (default is 15.0%). | Fault can be cleared when the chiller has stopped and the Clear Fault key is selected. | 13 |
| OIL – HIGH DILUTION INHIBIT | Start inhibit. Only applies when the Oil Quality Protection is enabled. | Oil Dilution is greater than the JCI Service programmable High Dilution Inhibit Trip Threshold (default is 20.0%). | Chiller can be started when the Oil Dilution is less than the High Dilution Start Inhibit Dilution Trip Threshold minus 0.2%. | 13 |
| OIL – LOW VISCOSITY INHIBIT | Start inhibit. Only applies when the Oil Quality Protection and Oil Cooling control are enabled. | Oil Viscosity is less than the JCI Service programmable Low Viscosity Inhibit Trip Threshold (default is 5.0 cSt) after 48 seconds of Pre-lube. | Chiller can be restarted after the Oil Viscosity is greater than the Low Viscosity Inhibit Trip Threshold plus 0.2 cSt. | 13 |
| MBC – INVALID SOFTWARE | Start inhibit. | MBC software major revision is greater than 0 and anything other than 5. | 13 | |
| WARNING – PURGE – EQUALIZATION LOW SUCTION TEMP | Auto reset warning (name used before Y.OPT.01.14.308). Inhibited purge operation while active. Renamed to WARNING – PURGE – EQ LOW SUCTION TEMP. | Auto reset. | 2 | |
| EVAPORATOR - TRANSDUCER OR LEAVING LIQUID PROBE | Safety fault. Starting with Y.OPT.01.14.308, only set when the head pressure is greater than or equal to 5 PSID. | 2 | ||
| MBC – POWER FAIL LANDING | Shutdown event; sets the Power Failing fault. | Battery Health Check must pass in order to clear the Power Failing fault (see UPS – PERFORM BATTERY HEALTH CHECK). | 2 | |
| WARNING - MOTOR - HIGH WINDING TEMPERATURE | Warning (YZ motor cooling). Threshold is the Motor High Winding Temp Fault Threshold minus 27.0°F. | 4 | ||
| MOTOR - HIGH WINDING TEMPERATURE | Safety shutdown (YZ motor cooling). Set at the Motor High Winding Temp Fault Threshold value (Admin programmable setpoint, default 270.0°F / 132.2°C). | 4 | ||
| MOTOR CURRENT > 15 %FLA | Start inhibit. Changed from a 5 second trip time to an immediate shutdown. | 6 | ||
| VSD - FREQUENCY > 0 HZ | Start inhibit. Changed from a 5 second trip time to an immediate shutdown. | 6 | ||
| VSD - HIGH PHASE A,B,or C INSTANTANEOUS CURRENT | Cycling fault for PYT model variable speed compressor drives only. Becomes a Safety fault if it occurs 6 times in 90 minutes (change from 3 times in 90 minutes). | 6 | ||
| VSD - HIGH PHASE A2,B2,or C2 INSTANTANEOUS CURRENT (dual) | Cycling fault for PYT model variable speed compressor drives only (dual). Becomes a Safety fault if it occurs 6 times in 90 minutes (change from 3 times in 90 minutes). | 6 | ||
| WARNING - OIL - HIGH SUMP PRESSURE | Auto reset warning (oil sump pressure events while in Heat Pump mode). | Any of the following, for the JCI programmable High Sump Pressure Trip Time (Oil Sump Setpoints screen): Oil Sump Pressure > 130.0 PSIG (42 C) AND Run Time < 10 Minutes; Oil Sump Pressure > 100.0 PSIG (34 C) AND Run Time >= 10 Minutes; or the oil sump pressure > 200 PSIG. | Auto reset. | 6 |
| OIL - HIGH SUMP PRESSURE | Safety fault (oil sump pressure events while in Heat Pump mode). | Any of the following, for the JCI programmable High Sump Pressure Trip Time (Oil Sump Setpoints screen): Oil Sump Pressure > 140.0 PSIG (42 C) AND Run Time < 10 Minutes; Oil Sump Pressure > 110.0 PSIG (34 C) AND Run Time >= 10 Minutes; or the oil sump pressure > 220 PSIG. | 7 | |
| OIL – LOW TEMPERATURE DIFFERENTIAL | Start inhibit. | Sets when the Oil Sump Temperature minus the Condenser Saturation Temperature is less than 40.0°F while the oil pump is running. | 8 | |
| OIL - HIGH SUMP PRESSURE – STOPPED | Start inhibit. | Oil Sump Pressure greater than 133.0 PSIG (changed from 132.0 PSIG). | Released when the pressure drops below 130.0 PSIG. | 8 |
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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.