On the display
The panel shows MON XX:XX AM - HIGH PRESSURE. The MON XX:XX AM prefix is the day and time of the shutdown entry; HIGH PRESSURE is the message itself.
What it means
This is a safety shutdown. The chiller has been shut down because condenser pressure has increased to 180 psig (1241 kPa) (R-134a). The message is prompted by the opening of the contacts of the High Pressure (HP) safety control, the control that senses condenser pressure. The system will be allowed to restart when the pressure decreases to 120 psig (827 kPa) (R-134a).
Why it appears
- Condenser pressure has increased to 180 psig (1241 kPa) (R-134a).
- The opening of the High Pressure (HP) safety control contacts prompted the shutdown and the message.
What to check
- Treat the message as a trip of the High Pressure (HP) safety control, the component that senses condenser pressure.
- Locate the HP safety control: it sits on a mounting bracket above the oil-pump starter, which is located on the condenser.
- Before attempting a restart, confirm that condenser pressure has decreased to 120 psig (827 kPa) (R-134a) — the system is allowed to restart only once it has.
Setpoints and thresholds
- Shutdown point: 180 psig (1241 kPa) (R-134a) — the condenser pressure at which the HP safety control contacts open and the HIGH PRESSURE shutdown occurs.
- Restart point: 120 psig (827 kPa) (R-134a) — the condenser pressure at which the system will be allowed to restart.
Reset and restart
Restart is a manual switch sequence, and it is possible only once the pressure has fallen: when condenser pressure has decreased to 120 psig (827 kPa) (R-134a), press COMPRESSOR switch to the STOP/RESET position and then to the START position
.
Questions engineers ask
What does HIGH PRESSURE mean on a York YK chiller?
The chiller is shut down on a safety trip because condenser pressure has increased to 180 psig (1241 kPa) (R-134a). The message is prompted by the opening of the High Pressure (HP) safety control contacts.
At what pressure does a York YK trip on HIGH PRESSURE, and when can it restart?
The shutdown occurs at 180 psig (1241 kPa) (R-134a). The system is allowed to restart when the condenser pressure decreases to 120 psig (827 kPa) (R-134a).
Where is the HP safety control on a York YK?
It is on a mounting bracket above the oil-pump starter, located on the condenser. This control senses condenser pressure, and its contacts open to prompt the HIGH PRESSURE shutdown.
How do I clear a HIGH PRESSURE shutdown on a York YK?
Wait for condenser pressure to decrease to 120 psig (827 kPa) (R-134a), then press the COMPRESSOR switch to the STOP/RESET position and then to the START position.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YK; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YK messages: fault codes · YORK YK documentation · YORK manuals