Issue:
Severe phase imbalance diagnostic
Resolution:
- If a compressor motor problem is suspected, changing the motor leads (phase A to B, phase B to C and phase C to A) to see if imbalance follows will determine if the issue is in the incoming power or in the motor. NOTE: Phase MUST remain clockwise direction!!!
- Verify that Current Transformers (CTs) are reading correctly.
- If all above are okay, it may be necessary to install a meter/recorder to show when and how large the imbalances occur.
- For some products, current imbalance protection may be disabled (15% protection) and a non-defeatable (30% or higher) severe phase imbalance protection would still be active. See proper IOM for this feature.
Facts:
- Air-Cooled Chiller (Pueblo) (RTAA 130-400 Ton)
- Air-Cooled Chiller (Pueblo) (RTAA 70-125 Ton)
- Air-Cooled Chiller (Pueblo) (RTAC)
- Water-Cooled Chiller (Pueblo) (RTHA)
- Water-Cooled Chiller (Pueblo) (RTHB)
- Water-Cooled Chiller (Pueblo) (RTHC)
- Water-Cooled Chiller (Pueblo) (RTHD)
- Water-Cooled Chiller (Pueblo) (RTWA)
- Checked CTs against ammeter--checked out fine.
Document Identifier: DOC-86685
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.