Issue:
Diagnostic: 1A5 or 1A6 Oil Flow Control
Resolution:
RTAA 130-400 TON chillers
This diagnostic is generated at the time compressor shuts down. The compressor will not restart.
- When the chiller control sends a signal to stop the compressor a 20 second Run: Unload timer starts. (Shutdown Test)
Next the UCM will de-energize the oil line solenoid and set a 10 +/- 1 second timer.
Usually the differential pressure switch will open in (0.8 - 1.2 sec.) and the compressor will be de-energized and the sequence ended.
- If the differential pressure switch does not open within 10 seconds, the compressor shall be de-energized and the (Oil Flow Control) CMR diagnostic will be generated not permitting the compressor to restart.
- The chiller control will not initiate the (Shutdown Test) whenever the fan control pressure differential is below 70 psid, or if a diagnostic shutdown occurs. The normal Shutdown Test will serve to check the differential pressure switch, the switch wiring to UCM, and closure of the oil line solenoid valve.
Troubleshooting:
- Verify DP Switch calibration...50 psi.
- Verify Master Oil Solenoid Valve is closing/shutting off.
- Verify DP Switch Capillary Tube connection points schrader/depressor are working correctly.
- Insert swivel "T's" on the low and high side of the DP switch and measure differential pressure during operation and shutdown.
Notes:
Changes:
Other Question/Problem/Cause Statements:
- Diagnostic: 1A5 or 1A6 Oil Flow Control
- Oil flow control?
Facts:
- Air-Cooled Chiller (Pueblo) (RTAA 130-400 Ton)
Original wave: wave9878
Document Identifier: DOC-76339
Document Identifier: 76339
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.