Earth Fault / Output Current Unbalance

What does 2330 mean?

The drive has detected a load unbalance, typically due to an earth fault in the motor or motor cable, or excessive output current unbalance in an inverter unit (for parallel connected modules). This condition poses a significant electrical safety risk, can lead to equipment damage, insulation breakdown, or fire, and indicates an internal fault if external causes are ruled out.

• Insulation breakdown between a motor phase winding and the motor frame, causing current to flow to earth (ground).
• Damage to the motor cable insulation (e.g., cuts, abrasions, moisture ingress) causing a short circuit to the cable shield or ground.
• Water or conductive dust ingress into the motor terminal box or the motor windings, creating a path to earth.
• Internal short circuit or failure within the drive's output inverter stage, leading to unbalanced phase currents.
• Faulty current sensor (Hall effect sensor) on one of the drive's output phases, providing an incorrect reading.

Click steps to track your progress.

1. 1

   1. Disconnect the motor cables from the drive, then measure insulation resistance of each motor phase to ground (PE) at the motor terminal box using a megohmmeter (e.g., 500VDC test voltage).

2. 2

   2. Measure insulation resistance of each motor cable phase conductor to its shield (or conduit) using a megohmmeter (e.g., 500VDC test voltage).

3. 3

   3. Visually inspect the motor terminal box for signs of moisture, contamination, or loose connections to the motor phases.

4. 4

   4. With motor cables disconnected, reset the drive and measure the output current (P1-16 or individual phase currents) from the drive to verify balance without load.

5. 5

   5. Inspect the motor cable for any visible signs of damage, pinching, or wear along its entire length.