Motor fan

What does A781 mean?

No feedback has been received from the external motor fan. This indicates that the fan may not be operating, leading to potential motor overheating if cooling is insufficient. The drive may continue operation, but motor thermal protection could eventually trip it.

• Motor fan's auxiliary contact or sensor feedback wiring is open-circuited, loose, or disconnected at the drive's input terminal (e.g., `X1/DI1`).
• Motor fan motor has failed or seized, preventing rotation and subsequent feedback generation.
• Incorrect parameter setting (e.g., `P30.10` (Motor fan supervision) is enabled but no feedback is connected or configured).
• Blown fuse or tripped circuit breaker in the motor fan's power supply circuit, preventing operation.

Click steps to track your progress.

1. 1

   Verify the motor fan's power supply (e.g., measure `230VAC` or `400VAC` at the fan's motor terminals) and check for continuity if a thermal switch or fuse is in line.

2. 2

   Inspect the feedback wiring (e.g., normally open contact `NO`) from the motor fan to the drive's digital input terminal (e.g., `X1/DI1`), ensuring secure connections and correct polarity.

3. 3

   Test the motor fan's operation manually by applying power directly and observing its rotation and the activation of its feedback switch.

4. 4

   Check the drive parameter (e.g., `P30.10` (Motor fan supervision)) to ensure it is configured correctly for the type of feedback (e.g., digital input) and delay.

5. 5

   Measure the resistance across the fan's feedback switch contacts (if present) to confirm operation (e.g., open circuit when stopped, closed when running).