Earth (ground) fault

Was bedeutet ALARM 14 ?

Current is flowing from the output phases to ground, either in the cable between the frequency converter and the motor, or within the motor itself. This is a severe fault that can cause electrocution, fire, and damage to the frequency converter or motor.

• Insulation breakdown in the motor windings, causing a path for current to flow to the motor frame (ground).
• Damaged or improperly installed motor cable (e.g., crushed, cut, water ingress) leading to insulation failure to ground.
• Water or contamination ingress into the motor terminal box or frequency converter output terminals (U, V, W).
• Incorrectly terminated motor cable shields, or shield damage, allowing phase-to-ground contact.
• Faulty ground detection circuit within the frequency converter.

Klicken Sie auf Schritte, um Ihren Fortschritt zu verfolgen.

1. 1

   Disconnect the motor cables (U, V, W) from the frequency converter output terminals and measure insulation resistance from each motor phase to ground using a megohmmeter (e.g., 500VDC).

2. 2

   Perform a visual inspection of the motor cable for any signs of damage, crushing, or water ingress along its entire length.

3. 3

   Check the motor terminal box for any signs of moisture, contamination, or loose wiring that could cause a ground fault.

4. 4

   Verify proper grounding of both the motor frame and the frequency converter chassis to the plant's earth ground system.

5. 5

   Isolate the fault by first testing the motor cable separately (disconnected from motor and frequency converter) for insulation resistance to ground.