YORK YK — Leaving Chilled Liquid - Flow Switch Open

The panel reads Leaving Chilled Liquid - Flow Switch Open; some manual tables and displays print it as Leaving chilled liquid - Flow switch open. It is one of the cycling faults of this chiller and is also recorded on the History Screen.

This is a chilled water flow switch cycling shutdown: flow through the evaporator was not proven while the machine was running or during its pre-lube period. The chiller stops, but the shutdown is not a lockout. While it is active, the evaporator pump relay contacts — also called the Chilled Water Pump contacts — (TB2-44/45) remain closed, so the pump keeps running until the chiller is given a stop command or trips on another fault.

• The chilled liquid flow switch has remained open for 5 continuous seconds while the chiller was running (with software version C.OPT.01.15A.xxx and earlier, the running threshold is 2 continuous seconds).
• The flow switch failed to close during the last 5 seconds of the system pre-lube period.

• Running open-time threshold: 5 continuous seconds in current software; 2 continuous seconds with software version C.OPT.01.15A.xxx and earlier.
• Pre-lube requirement: the switch must close during the last 5 seconds of the system pre-lube period.
• This extended flow switch delay is implemented for both ANALOG and DIGITAL flow sensor selections.

The manuals describe no manual reset for this message. They state the recovery directly: The chiller will automatically restart when the flow switch closes. Until that happens, the pump contacts (TB2-44/45) stay closed while the shutdown is active, and they only open when a stop command is given or another fault occurs.