Current Detection Circuit Fault

What does Er - 12 mean?

The current flow exceeded the motor rated current, the current detection value symbol was reversed, or there is an open-phase condition on any of the U/T1, V/T2, and W/T3 output terminals. This indicates a severe issue with the motor wiring or the drive's internal current detection, risking motor or drive damage.

• Open phase condition on one of the motor output terminals (U/T1, V/T2, W/T3) or within the motor winding, leading to severely unbalanced current detection.
• Internal drive current sensor fault or current detection circuit malfunction (e.g., offset error, current signal reversal).
• Severe motor overload condition causing actual current to exceed the drive's detection threshold for an extended period.
• Drive output phase short-circuited to ground or between phases, leading to immediate, excessive current flow.
• Incorrect motor rated current (P2-01) or drive rated current configured incorrectly after a control board or power section replacement.

Click steps to track your progress.

1. 1

   1. Disconnect the motor from drive output terminals U/T1, V/T2, W/T3. Perform an insulation resistance test (megger) on each motor phase to ground and between phases.

2. 2

   2. Verify all motor cable connections at the drive output terminals (U/T1, V/T2, W/T3) and motor terminal box are tight and free of corrosion.

3. 3

   3. With motor disconnected, measure resistance between phases (U-V, V-W, W-U) at the drive output terminals; all values should be balanced within 5%.

4. 4

   4. Verify motor rated current (P2-01) and motor overload protection (L3-01) parameters are correctly set according to motor nameplate data.

5. 5

   5. If issue persists with the motor disconnected, perform a static test on the drive's output transistors (IGBTs) as per the manufacturer's service manual to check for internal current sensor or power circuit faults.