On the display
The message line shows POWER FAILURE, printed with the time stamp the manual shows in front of it: MON XX:XX AM - POWER FAILURE. The manual lists one other form of the same message: when the Micro Board is configured for auto-restart after power failure, the line reads MON XX:XX AM - POWER FAILURE - AUTOSTART.
What it means
The chiller has been shut down — a cycling shutdown — because there has been a power interruption or failure. This message is displayed when the Micro Board is configured for MANUAL RESTART AFTER POWER FAILURE, which is the factory setting: it was made by removing the two-pin jumper from the terminals labeled "Auto R" (J60) on the Micro Board. The message reports the loss of supply power itself; it is the restart configuration of the Micro Board that decides what has to happen before the chiller can run again.
Why it appears
- A power interruption or failure has occurred — this is the cause the manual gives for the shutdown.
- The message appears in its manual-restart form because the Micro Board is configured for MANUAL RESTART AFTER POWER FAILURE (factory setting; the two-pin jumper has been removed from the "Auto R" (J60) terminals).
What to check
- Confirm that a power interruption or failure actually took place — this message reports exactly that event.
- Wait until utility power has been restored before working at the panel.
- If the chiller is expected to restart on its own the next time, check the Micro Board for the two-pin jumper on the "Auto R" (J60) terminals; the factory manual-restart setting has it removed.
Setpoints and thresholds
- Factory configuration — MANUAL RESTART AFTER POWER FAILURE: accomplished by removing the two-pin jumper from the terminals labeled "Auto R" (J60) on the Micro Board.
- Auto-restart configuration: take one of the two-pin program jumpers from the cloth bag located inside the Control Center and place it on the terminals labeled "Auto R" (J60) on the Micro Board.
Reset and restart
With the factory manual-restart configuration the chiller does not come back by itself. The manual's action for this message: When power is restored, pressing the COMPRESSOR switch to STOP/RESET position and then to START position can restart the chiller.
With the auto-restart configuration instead, no action is required — the chiller will automatically restart when power is restored, and the message line then shows the AUTOSTART form.
Questions engineers ask
How do I restart a YORK YK after the POWER FAILURE message?
Once utility power is restored, press the COMPRESSOR switch to the STOP/RESET position and then to the START position. The chiller can then be restarted from the panel.
Will the YORK YK restart by itself after a power failure?
Only when the Micro Board is configured for auto-restart, which needs the two-pin jumper fitted on the "Auto R" (J60) terminals. The factory setting is manual restart, so normally the COMPRESSOR switch must be cycled after power returns.
Why does the panel show POWER FAILURE?
The chiller shut down because utility power was interrupted or failed. The manual-restart form of the message is shown because the Micro Board is set for MANUAL RESTART AFTER POWER FAILURE.
What is the factory restart setting after a power failure on the YK?
Manual restart after power failure, made by removing the two-pin jumper from the "Auto R" (J60) terminals on the Micro Board. A jumper from the cloth bag inside the Control Center can be fitted on J60 to convert the unit to auto-restart.
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