Abnormally High Compressor Current

What does E42 mean?

Abnormally high current has been detected in the compressor, indicating a potential electrical or mechanical fault with the compressor, or system overload. This can lead to compressor failure if not addressed.

• Compressor is drawing abnormally high current.
• Mechanical issue within the compressor (e.g., locked rotor, winding short).
• Overload on the compressor due to system faults.
• Faulty current sensor (CT) monitoring compressor current.
• Low voltage supply to the compressor.

Click steps to track your progress.

1. 1

   Measure the compressor operating current on all phases and compare to the motor nameplate FLA value.

2. 2

   Check for signs of compressor mechanical binding or damage by attempting to rotate the shaft (if safe and accessible).

3. 3

   Verify system refrigerant charge and pressure for potential overcharge or non-condensables, using a manifold gauge set.

4. 4

   Inspect power supply voltage to the outdoor unit and check for phase imbalance or low voltage conditions.