YORK YK — Oil - High viscosity

The panel prints the message as Oil - High viscosity; one of this chiller's manuals lists it in capitals as OIL - HIGH VISCOSITY. Both spellings name the same event, which the manual classifies as an immediate safety fault.

This is an immediate safety fault of the YK: the oil kinematic viscosity has been greater than the programmed high viscosity trip limit for long enough for the control to trip. The message is armed only when the Oil Quality Protection AND Oil Cooling control features are both enabled — if either feature is disabled, this fault does not apply. It can be cleared only after the chiller has stopped.

• The fault only applies when the oil quality protection and oil cooling control are both enabled.
• The chiller has been running for 30 min and, at the same time, the oil kinematic viscosity has been greater than the JCI Service programmable High Viscosity Trip Threshold (default 30.0 cSt) for 5 min.

• High Viscosity Trip Threshold — programmable through JCI Service; default is 30.0 cSt.
• Running time before the trip condition applies: 30 min of chiller running.
• Time the viscosity must stay above the threshold to trip: 5 min.
• Feature gate: Oil Quality Protection AND Oil Cooling control must both be enabled.

The fault clears only after the chiller has stopped. Once the machine is stopped, press the Clear button next to the listed event on the Systems Details Screen, or select the Clear Fault key — the model's manuals describe the same action with different key names. One of them states: The fault can be cleared after the chiller has stopped and the Clear Fault key is selected.