YORK YK — Oil - High supply temperature

The panel shows the message as Oil - High supply temperature; some manuals print it in capitals as OIL - HIGH SUPPLY TEMPERATURE. It is grouped with the safety fault messages of the control center, not with the ordinary display warnings, so it is a stop fault for the machine.

This is a safety fault of the oil cooling control function, and it is armed only when oil cooling control is enabled on the unit. When it trips, the chiller is stopped on a safety fault: it cannot be started again until the oil supply temperature has fallen back below the trip threshold and the fault has been cleared by hand.

• Oil cooling control is enabled. The manuals state that this safety message appears when oil cooling control is enabled on the unit.
• The oil supply temperature ran high. After the minimum running time — one manual states 5 minutes of chiller running, the other 30 minutes — the oil supply temperature, as sensed by the oil supply temperature thermistor, rose 15°F (8.3°C) above the service-programmable oil supply temperature setpoint.
• The excess lasted long enough. The temperature stayed above that margin for 1 continuous minute, and the safety fault was issued.

• Oil supply temperature setpoint: service-programmable, default 120°F (48.9°C).
• Trip threshold: oil supply temperature setpoint + 15°F (8.3°C) — the same margin is printed in the second manual as setpoint + 15.0°F.
• Trip timing: the excess temperature must persist for 1 min, counted from the minimum running time (5 min in one manual, 30 minutes in the other).
• Clear threshold: the oil supply temperature must be lower than the oil supply temperature setpoint + 15.0°F again before the fault can be released.
• Mode requirement: oil cooling control must be enabled for this fault to be active.

This fault needs a manual clear — it does not reset on its own. Let the oil supply temperature fall back below the trip threshold (setpoint + 15°F / 15.0°F); the chiller stays locked out until then. The manual's wording for the restart: The chiller can be started after the temperature decreases below the trip threshold and the Clear button is pressed next to the listed event on the Systems Details Screen. The second manual describes the same manual clear: once the oil supply temperature is lower than the oil supply temperature setpoint + 15.0°F, the fault is released when the Clear Fault key is pressed. After clearing, the chiller can be started again.