Compressor Overcurrent Interruption (Extended Operation)

What does UP (1100) mean?

An overcurrent condition on the DC bus or compressor is detected after the compressor has been operating for 30 seconds. This differs from UF (100) which occurs within 30 seconds of start-up. Causes can include a closed stop valve, decreased power supply voltage, loose/disconnected/reversed compressor wiring, defective indoor/outdoor fans, short cycling of units, a defective input circuit of the outdoor controller board, or a defective compressor.

• Compressor tripped due to excessive current during extended operation.
• Overload on the compressor.
• Low refrigerant charge causing increased compressor work.
• Faulty compressor.
• Electrical supply issues to the compressor motor.

Click steps to track your progress.

1. 1

   Open the stop valve of the outdoor unit.

2. 2

   Check the facility of the power supply.

3. 3

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

4. 4

   Check the indoor/outdoor fan motors.

5. 5

   Solve the short cycle issue by addressing airflow obstructions or incorrect unit placement.

6. 6

   Replace the outdoor controller circuit board.