Earth fault 2 (Ground fault)
Danfoss · VLT HVAC Drive High Power
Was bedeutet 45 ?
A ground fault has been detected in the system, meaning current is flowing to earth through an unintended path. This is a critical safety issue that can cause electrical shock, equipment damage, or fire if not immediately addressed.
Häufige Ursachen
- Motor winding insulation breakdown to the motor frame (phase-to-ground fault).
- Motor cable insulation failure to ground (e.g., due to chafing, mechanical damage, water ingress).
- Water or conductive debris in the motor terminal box causing a phase-to-ground short.
- Faulty insulation in associated equipment (e.g., reactors, filters) connected to the motor output.
- Damage to the frequency converter's output stage (e.g., IGBT failure to ground).
Reparaturschritte & Checkliste
Klicken Sie auf Schritte, um Ihren Fortschritt zu verfolgen.
- 1
Disconnect main power supply to the frequency converter at the upstream breaker. Verify zero voltage at L1, L2, L3 terminals.
- 2
Disconnect the motor cables (U, V, W) from the frequency converter output terminals (T1, T2, T3).
- 3
Measure insulation resistance from each motor phase (U, V, W) to motor frame ground using a megohmmeter (e.g., 500VDC or 1000VDC).
- 4
Measure insulation resistance from each motor cable conductor (T1, T2, T3) to earth ground (cable shield/conduit) with the motor disconnected.
- 5
Visually inspect the motor cable along its entire length for signs of damage to the outer jacket or inner insulation.
- 6
If insulation resistance is below acceptable limits (e.g., < 1 Megohm), isolate the faulty component (motor or cable) and replace.