Evaporator Solution Flow Loss - Shell and Tube Heat Exchangers

Evaporator Solution Flow Loss - Shell and Tube heat exchangers CGAF.

The information below is for units built prior to 5/03 (10th digit of model number A-G).

• For units built after 5/03 (10th digit of model number H-Z) see this Article: Evaporator Solution Flow Loss - Brazed Plate heat exchanger
• This diagnostic is generated when the Cold Generator Module (CGM, 1U48) detects a loss of flow through the evaporator.
• A loss of flow is determined by comparing the entering and leaving solution temperatures of the evaporator.
• This is a manual reset diagnostic. The unit controls must be manually reset to clear the diagnostic.
• Cycling unit power or diagnostic reset through the Human Interface will clear the diagnostic.

Items to check include:

1. Flow
2. Evaporator Leaving Solution Temperature Sensor
3. Evaporator Entering Solution Temperature Sensor

Here are the steps for Intellipak Air-Cooled Chiller

1. Flow
   • Verify that flow exists through the evaporator and that the flow rate is correct for the size of evaporator being used. Refer to the flow rate table in the IOM for the proper flow rates.
      
2. Evaporator Leaving Solution Temperature Sensor
   • The Evaporator Leaving Solution Temperature Sensor could be faulty. Refer to the Evaporator Leaving Solution Temperature Sensor Failure diagnostic for information on troubleshooting the sensor.
      
3. Evaporator Entering Solution Temperature Sensor
   • The Evaporator Entering Solution Temperature Sensor could be faulty. It is also possible that the sensor is not positioned properly. Generally the sensor should be inserted into the evaporator barrel until contact is made with the refrigeration tubing and then backed out  of an inch. Refer to the Evaporator Entering Solution Temperature Sensor Failure diagnostic for information on troubleshooting the sensor.

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.