Compressor failure

What does #49 mean?

This alarm indicates a potential issue related to the compressor. The manual suggests it might not be a direct compressor or drive failure itself but a symptom of another problem, requiring further investigation to determine the root cause. This fault prevents the system from operating correctly.

• Motor overload due to high head pressure or mechanical binding (e.g., seized bearings) within the compressor.
• Inadequate lubrication causing increased friction and overheating, leading to a rise in compressor motor current.
• Discharge pressure switch (e.g., PS-3) tripping prematurely due to clogged condenser or cooling fan failure, indicating system pressure is too high.
• Drive (VFD) fault indicating overcurrent or undervoltage conditions on the compressor motor, preventing proper operation.
• Temperature sensor (e.g., RTD on motor winding or discharge line) reporting an over-temperature condition, triggering a protective shutdown.

Click steps to track your progress.

1. 1

   Isolate power, then measure motor winding resistance between phases U, V, W for continuity and balanced values (e.g., ±5% tolerance).

2. 2

   Check for mechanical free movement of the compressor shaft (if accessible and safe) to identify internal binding or seized components.

3. 3

   Verify discharge pressure transducer (e.g., PT-1) readings against actual system pressure using a calibrated gauge to confirm accuracy.

4. 4

   Inspect lubrication oil level and quality (e.g., contamination, viscosity) according to OEM specifications for the compressor model.

5. 5

   Check drive parameters P1-05 (Motor Rated Current) and P2-01 (Overload Trip Level) are set correctly for the compressor motor's nameplate data.