Optical Oil Loss Level Sensor Checkout

Issue:

Optical oil loss level sensor not reading 

Resolution:

Optical Oil Loss Level Sensor Checkout 

CAUTION:  Never perform this test while the compressor is running.  Turn the chiller off and ensure that the compressor will not start.

• Verify that the wiring between the optical sensor and the oil loss level module.
  • RTHD: 1A11 J2-1, 2 and 1A3 J3-1
  • RTWD: 1A23 J2-1, 2 or J2-3, 4 and 1A3 J3-1 or 1A4 J3-1
  • RTAF: 1K15 J2-1, 2 or J2-3, 4 and wired back to 1T7 DC Power Supply
  • RTAE: 1K17 J2-1, 2 or J2-3, 4 and wired back to 1K18 Quad Relay Output Condenser Fan Enable Module
  • ACR: 1K17 J2-1, 2 or J2-3, 4 and wired back to 1T15 DC Power Supply

• Remove the sensor from the oil separator (or oil sump), chiller dependent
  • Unscrew the sensor for removal
  • Older chillers require the snap ring to be removed for sensor removal
  • Note: The optical sensor is separated from the refrigerant by a clear prism, therefore, it is not necessary to recover refrigerant when removing the sensor.

• Where to view status of oil loss level sensor
  • CH530 Controls:
    • RTHD – Oil loss sensor status is on the reports tab under the compressor sub-menu
    • RTWD – Using Techview, go to Unit View → Circuit 1 I/O States or Circuit 2 I/O States
  • UC800 Controls - From TD7 Display, Reports → Compressor → (Circuit 1 or Circuit 2) → Oil Loss Level Sensor
  • Symbio Controls - From TD7 Display, Reports → Compressor → (Circuit 1 or Circuit 2) → Oil Loss Level Sensor
• Checking Optical Sensor
  • Pull Sensor
  • Cover with thumb/tape → simulate WET
  • Uncover (Use white paper) → simulate DRY
  • If fails either, proceed to validating if module is good.
     
• Checking Oil Loss Level Sensor Module  
  • Verify 24 VDC incoming to Oil Loss Level Module, if not why (wiring, supply, etc)?
  • Disconnect sensor from module
  • Jump wire on terminals J2-1 & J2-2 or J2-3 & J2-4 (as necessary). This shorts out module to simulate good optical sensor.  ( Jumper IN → WET / OUT → DRY)
     

Notes:

• For RTHC units, the optical eye procedure can be found in RTHC-SVD01B-EN Page 57 and the status of the optical eye in Compressor report menu.

• If during operation the optical eye goes "Dry" the chiller or circuit will stop and will call for "Loss of Ooil at Compressor - Running"

• If the optical eye goes "Dry" when the chiller/circuit is not running, the following will occur.  When the compressor is called to run as part of the start sequence, the optical eye will be reporting "dry".  The unit will abort the start and will annunciate  "Loss of Oil at Compressor -Stopped"
• Never bypass the optical eye unless to run test a compressor or the compressor could fail mechanically.

Resources Available:

• Tech TV Video(s):
  • Rotary Chillers: Troubleshooting Optical Sensors 

• Reference Literature:
  (Electronic copies can be pulled from e-library at Trane Residential (tranetechnologies.com))
  • Service Bulletin: RLC-SVD05A-EN, RTHC-SVD01B-EN
• Other:
  • N/A

Other Question/Problem/Cause Statements:

• How do I check the optical oil sensor

Facts:

• Air Cooled (Pueblo)
• Water Cooled (Pueblo)

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.