Excessive open circuit voltage to motor armature circuit.

What does 931 mean?

This fault occurs when the measured armature voltage is greater than 10% of the rated volts (parameter #7) during an open circuit test. It may occur during Self-Tune (Function #997) or Self-Diagnostic (Function #998).

• Motor is rotating, generating Counter-Electromotive Force (CEMF).
• Unbalanced SCR leakage when parameter #7 (Rated Armature Volts) is set to a low value.
• Damaged SCR(s).

Click steps to track your progress.

1. 1

   Ensure the motor is not rotating during the test to prevent CEMF generation.

2. 2

   Temporarily increase parameter #7 (Rated Armature Volts) for the test if unbalanced SCR leakage is suspected.

3. 3

   Perform Self-Diagnostics (Function #998) to check for damaged SCR(s).