Compressor Overcurrent Interruption (Locked)

What does UF (100) mean?

An overcurrent condition on the DC bus or compressor is detected within 30 seconds after the compressor starts operating. This indicates a locked compressor state. Common causes include a closed stop valve, decreased power supply voltage, loose, disconnected, or reversed compressor wiring connection, a defective compressor, or a faulty outdoor power board.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Correct the U·V·W phase wiring to the compressor. Refer to section 10-9 (Outdoor power circuit board).

2. 4

   Check the compressor. Refer to section 10-6.

3. 5

   Replace the outdoor power circuit board.