Low read-back volts from DC bus circuit.

What does 938 mean?

This fault indicates that a low voltage read-back is detected from the DC bus circuit. This can occur during Self-Tune (Function #997) or Self-Diagnostic (Function #998). For drives larger than 300 amps DC, this involves discrete wires.

• Missing wire connected to the bus voltage feedback circuit.
• Component problem where the feedback voltage divider ratio does not match the one identified in the Cube ID PCB.

Click steps to track your progress.

1. 1

   Check for any missing wires connected to the bus voltage feedback circuit.