On the display
The display shows Power fault. This message applies to EM starter applications only. When the fault occurs, the power fault LED on the CM-2 illuminates to identify that this fault has occurred. The manual lists Power fault under its cycling faults messages.
What it means
After the chiller has been running for 75 s, the CM-2 board has shut down the chiller to protect the motor from a transient torque condition. The board reacted because the CM contacts located in the CM-2 board have momentarily opened for less than 3 s. These contacts are connected between TB6-16 and TB6-53 in the control center. In short, the panel is reporting a protective shutdown of the chiller by the CM-2 board, carried out to protect the motor.
Why it appears
- The CM contacts located in the CM-2 board have momentarily opened for less than 3 s.
- In response, the CM-2 board shuts the chiller down to protect the motor from a transient torque condition.
- The fault arises in EM starter applications only, after the chiller has been running for 75 s.
Setpoints and thresholds
- 75 s — the chiller running time after which this fault occurs.
- Less than 3 s — how long the CM contacts in the CM-2 board were open.
Reset and restart
The chiller comes back on its own: The chiller automatically restarts when the contacts close.
Questions engineers ask
What does Power fault mean on a YORK YK chiller?
In EM starter applications it means that the CM-2 board has shut the chiller down to protect the motor from a transient torque condition. The power fault LED on the CM-2 illuminates to identify that this fault has occurred.
Why does my YORK YK show Power fault?
The CM contacts located in the CM-2 board have momentarily opened for less than 3 s. These contacts are connected between TB6-16 and TB6-53 in the control center, and the message appears after the chiller has been running for 75 s.
How does a YORK YK recover from a Power fault?
The chiller automatically restarts when the contacts close.
Where are the CM contacts connected for this fault?
The CM contacts of the CM-2 board are connected between TB6-16 and TB6-53 in the control center.
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