Power Module Abnormality

What does U6 mean?

An abnormality is detected in the power module, often signaled by overcurrent during module operation (which can trigger UF or UP errors). This critical fault can be caused by a closed outdoor stop valve, low power supply voltage, incorrect or loose compressor wiring, or a defective compressor or outdoor power circuit board.

• Power module failure or internal short circuit.
• DC bus voltage abnormal.
• Control board communication error with power module.
• Overcurrent or overvoltage protection triggered within the power module.

Click steps to track your progress.

1. 1

   Verify that the outdoor stop valve is fully open.

2. 2

   Check the facility's power supply voltage to ensure it meets the system specifications.

3. 3

   Correct the wiring (U, V, W phase) to the compressor if any connections are loose, disconnected, or conversed.

4. 4

   Check the compressor for defects, referring to diagnostic procedures in section 10-6 of the manual.

5. 5

   If the above steps do not resolve the issue, replace the outdoor power circuit board.