Unbalance

What does 18 mean?

An unbalance has been detected between power modules within paralleled power units. This signifies a discrepancy in current sharing or performance among the modules, which can lead to uneven wear and a reduced lifespan of the power components. If persistent, this fault indicates an internal issue within the paralleled power system.

• Uneven impedance or resistance in output cabling (U, V, W) between parallel power modules and the common motor.
• Faulty current sensor or measurement circuit within one of the paralleled power modules causing inaccurate current feedback.
• Mismatched firmware versions or parameter settings (e.g., P5-10 "Parallel control mode") between the paralleled power modules.
• Degradation or failure of switching components (IGBTs) in one power module, leading to poor current regulation.

Click steps to track your progress.

1. 1

   Verify uniform length and gauge of output cables (U, V, W) from each power module to the common motor connection point.

2. 2

   Check for loose or corroded connections on output terminals (U, V, W) and input terminals (R, S, T) of each power module.

3. 3

   Compare current feedback values (e.g., P0-01) from each individual power module using a multimeter with a current clamp or through the drive's display.

4. 4

   Confirm all paralleled power modules have identical firmware versions and critical parallel control parameters (e.g., P5-10, P5-11, P5-12) are correctly configured.

5. 5

   Isolate each power module, if possible, and run independently to identify which module exhibits abnormal current draw or output.