Danfoss · VLT Micro Drive FC 51
A short circuit has been detected in the motor windings or on the motor terminals. This is a severe fault that can cause immediate and catastrophic damage to the drive's output stage if not quickly and effectively protected against, representing a major electrical failure.
Click steps to track your progress.
Immediately disconnect the motor cables from the drive's output terminals (U, V, W) and then power cycle the drive.
Using an ohmmeter, measure resistance between all three motor output phases (U-V, V-W, U-W) and from each phase to ground at the drive's output terminals.
Visually inspect the motor terminal box and the entire motor cable for any signs of physical damage, arcing, or foreign objects.
Measure the resistance of each motor winding (e.g., Phase U to Phase V, V to W, W to U) directly at the motor, expecting balanced low resistance values.
If an output filter or motor contactor is used, disconnect it and test the drive independently to isolate the faulty component.