Drive: Short-circuit detected

What does F07807 mean?

A phase-to-phase short-circuit has been detected at the motor-side output terminals of the converter. This is a critical fault that can severely damage the power unit if not resolved. It can also be triggered if the line (input) and motor (output) cables are accidentally interchanged, creating a short circuit condition.

• Insulation breakdown in the motor output cable (U, V, W phases) due to mechanical damage, age, or moisture ingress.
• Internal short-circuit within the motor windings (phase-to-phase or phase-to-ground) due to overheating or insulation failure.
• Foreign conductive material or debris bridging output terminals on the drive or motor side.
• Malfunctioning output IGBTs or power module within the drive, causing a direct short to occur.

Click steps to track your progress.

1. 1

   1. Disconnect the motor cables from the drive's output terminals (U, V, W).

2. 2

   2. Measure resistance between motor phases (U-V, V-W, W-U) at the disconnected motor cable ends using a multimeter to detect a short-circuit (< 1 Ohm).

3. 3

   3. Perform an insulation resistance test (Megger test) between each motor phase and ground, and between phases, at the motor terminals.

4. 4

   4. Inspect the drive's output terminals for signs of arcing, carbon tracking, or conductive debris.

5. 5

   5. If the motor cable or motor itself is confirmed shorted, replace the damaged component. If they test clear, replace the drive's power module or the entire drive unit.