Output Ph Loss

Hva betyr F021 ?

One or more of the output phases (U, V, W) to the motor has been lost or is significantly unbalanced, if this function is enabled (A557 [Out Phas Loss En]). This condition can lead to severe motor overheating, vibration, and damage if the motor continues to operate on reduced phases.

• Open circuit in one of the motor phases (U, V, or W) due to a broken conductor within the motor cable.
• Loose or corroded connection at the drive output terminals (U, V, W) or within the motor terminal box.
• Internal drive power module (IGBT) failure affecting one specific output phase.
• Damaged motor winding or internal connection creating an open circuit in one phase of the motor.
• Output Phase Loss Enable (A557 [Out Phas Loss En]) activated, and a significant unbalance in output currents is detected.

Klikk på steg for å spore fremgangen.

1. 1

   Disconnect the motor from the drive. Measure resistance between each pair of motor phases (U-V, V-W, W-U) at the motor terminal box, ensuring readings are balanced within 5% and match motor data.

2. 2

   With motor cables disconnected from the drive, measure continuity of each output cable conductor (U, V, W) from the drive to the motor end, ensuring no open circuits.

3. 3

   Inspect and tighten all motor cable connections at the drive output terminals (U, V, W) and within the motor terminal box.

4. 4

   If parameter A557 (Out Phas Loss En) is enabled, consider temporarily disabling it to isolate whether the fault is due to detection sensitivity or an actual phase loss.

5. 5

   Visually inspect the drive's output terminals and power modules (if safely accessible) for signs of arcing or component damage.