YORK YK — Oil - High sump pressure

The display shows Oil - High sump pressure; the manuals also print the message as OIL - HIGH SUMP PRESSURE. It is a safety fault message and appears only while heat pump mode is enabled.

The chiller has tripped on the high oil sump pressure safety. While heat pump mode is enabled, the control center watches the oil sump pressure against two run-time bands and one absolute limit: a higher pressure is tolerated only during the first minutes of running, a lower limit applies once the chiller has run longer, and an extreme pressure trips the safety instantly at any time. Each pressure condition must persist for the trip time before the safety is set — the fault tables print this hold as 10 s, and the timing is the JCI programmable High Sump Pressure Trip Time on the Oil Sump Setpoints screen. Because this is a safety fault, it clears only when the chiller is in a stopped state.

• Heat pump mode is enabled — the safety exists only in heat pump operation.
• Oil sump pressure greater than 140.0 psig while the chiller has been running less than 10 min.
• Oil sump pressure greater than 110.0 psig once the chiller has been running for 10 min or more.
• Oil sump pressure greater than 220 psig at any time — this trips the safety instantly.

• Trip level, run time less than 10 minutes: oil sump pressure greater than 140.0 PSIG.
• Trip level, run time 10 minutes or more: oil sump pressure greater than 110.0 PSIG.
• Instant trip level: oil sump pressure greater than 220 PSIG.
• Hold time: printed as 10 s in the fault tables; the duration is the JCI programmable High Sump Pressure Trip Time on the Oil Sump Setpoints screen.

The safety does not clear while the chiller runs. The fault clears when the chiller is in a stopped state and the Clear button is pressed next to the listed event on the Systems Details Screen. The other manual describes the same action as pressing the CLEAR FAULT key on the display once the chiller is stopped.