Loop Contactor Failure

What does F402 mean?

This fault indicates that the main loop contactor has failed to pick (close) after the drive has been commanded to run. This prevents the armature circuit from being energized, thereby inhibiting motor operation. The drive detects this if the field current (referenced by setting #32) is not sufficient to pick the contactor.

• The loop contactor coil is not receiving sufficient voltage or current to activate.
• Field current is not established or is below the required threshold (setting #32) for the contactor to pick.
• Mechanical fault or sticking within the loop contactor mechanism prevents closure.

Click steps to track your progress.

1. 1

   Verify the "Hardware Run" input (or "Run-Up" / "Run-Down" contact) is active and sending a command to the drive.

2. 2

   Measure the field current and confirm it is above the threshold set by parameter #32.

3. 3

   Inspect the loop contactor's coil for continuity and measure the voltage across its terminals when a run command is active.

4. 4

   Check the auxiliary contacts of the loop contactor for proper operation and cleanliness.