Short-circuit

What does 16 mean?

A short-circuit condition exists on the motor terminals or within the motor windings. This severe fault can lead to significant damage if not addressed quickly.

• Motor winding insulation breakdown due to overheating, aging, or voltage spikes.
• Motor cable insulation failure (phase-to-phase or phase-to-ground) from mechanical damage, abrasion, or chemical exposure.
• Water ingress into motor terminal box or motor leading to resistive or direct short-circuit.
• Improperly sized or damaged motor contactor or relay with welded contacts causing a persistent short.
• Loose or corroded connections at motor terminals or within the drive output terminals.

Click steps to track your progress.

1. 1

   Immediately disconnect power to the drive and motor. Verify zero voltage at drive output terminals T1, T2, T3 (U, V, W).

2. 2

   Isolate the motor by disconnecting all three phases (U, V, W) at the drive output terminals.

3. 3

   Using a multimeter, measure resistance between motor terminals U-V, V-W, and W-U. All three readings should be similar and within motor specifications.

4. 4

   Using a megohmmeter (insulation resistance tester), measure insulation resistance from each motor phase (U, V, W) to motor ground. Readings should be >100MΩ (at 500VDC).

5. 5

   Inspect motor cables for visible damage, pinch points, or signs of overheating along their entire length from drive to motor.

6. 6

   If motor and cables test OK, inspect the drive's output power module (IGBTs) for signs of damage or shorting (requires qualified technician and specific test equipment).