Output phase supervision

What does 11 mean?

The drive's current measurement system indicates no current flowing in one of the motor phases. This suggests a problem with the motor cable connection, a break in the cable, or an issue within the motor itself, such as an open winding. Operating the drive with a missing output phase can severely damage both the motor and the drive's inverter section.

• Open circuit in one of the motor phases (U, V, or W) due to a broken conductor in the motor cable.
• Loose or corroded connection at the drive output terminals (U, V, W) or the motor terminal box.
• Failure of an internal motor winding, resulting in an open circuit.
• Incorrectly sized motor cable or a cable run that is too long, causing excessive voltage drop and current imbalance.
• Malfunction of the drive's internal current sensor for one specific output phase.

Click steps to track your progress.

1. 1

   Measure the resistance between each motor phase (U-V, V-W, W-U) at the drive's output terminals (with motor disconnected from drive) using a multimeter, comparing values for balance.

2. 2

   Perform a continuity test on each motor cable conductor (e.g., U to U, V to V, W to W) from the drive output to the motor terminal box.

3. 3

   Inspect all connections at the drive output terminals (U, V, W) and inside the motor terminal box for tightness, corrosion, or signs of overheating.

4. 4

   Check for visual damage to the motor cable insulation along its entire length.

5. 5

   Run the drive with the motor disconnected (if safe and permissible per manufacturer) and monitor output currents (e.g., parameter A5-05) to check for internal drive issues.