Refrigerant Circuit Problems
System Condition 6
1. The low pressure gauge reading does not change. The pressure should rise when the compressor is not in operation. For normal operating pressures, refer to Table 1.
2. High pressure gauge reading is at the high end of the normal range.
Note: Ambient temperature is above 21°C (70°F).
3. The temperature of the air flow from the evaporator is partially cool.
Probable Cause
The system has air or moisture in the system. The system does not have a full charge of refrigerant.
* Perform a leak test and carefully test around the compressor seal. Refer to the Service Manual, SENR5664, "Refrigerant Leakage - Test" section in Testing and Adjusting.
* Recover the refrigerant from the system. Refer to the Service Manual, SENR5664, "Refrigerant Recovery" section in Testing and Adjusting.
* Repair leaks.
* Check the compressor for loss of oil.
* Evacuate the system. Refer to the Service Manual, SENR5664, "Refrigerant System - Evacuate" section in Testing and Adjusting.
* Charge the system with the correct amount of refrigerant. Measure the refrigerant by weight. Refer to the Service Manual, SENR5664, "Refrigerant System - Charge" section in Testing and Adjusting.
* After the system is charged and operated for a minimum of ten minutes, perform a performance check. Refer to "Performance Checks for the Air Conditioning System" section.
System Condition 7
1. Low pressure gauge reading is above normal. For normal operating pressures, refer to Table 1.
2. High pressure gauge reading is above normal. For normal operating pressures, refer to Table 1.
Note: Ambient temperature is above 21°C (70°F).
3. High pressure (liquid line) is very hot.
4. The compressor may become noisy and the drive belt may slip.
Note: The compressor is not operating under ambient temperatures that are extreme. The compressor is not operating under high humidity that is extreme.
Probable Cause
The system is overcharged.
* Recover the remaining refrigerant. Refer to the Service Manual, SENR5664, "Refrigerant Recovery" section.
* Charge the system with the correct amount of refrigerant. Measure the refrigerant by weight. Refer to the Service Manual, SENR5664, "Refrigerant System - Charge" section in Testing and Adjusting.
* Perform a performance check. Refer to "Performance Checks for the Air Conditioning System" section.
Note: Perform the following procedure if the system has not been serviced for a extended period of time. Perform the following procedure if the pressures of the system are not within the correct specifications.
* Recover the refrigerant. Refer to the Service Manual, SENR5664, "Refrigerant Recovery" section.
* Evacuate the system. Refer to the Service Manual, SENR5664, "Refrigerant System - Evacuate" section in Testing and Adjusting. If service work has not been performed for a extended period of time, replace the receiver-dryer or the in-line dryer.
* Charge the system with the correct amount of refrigerant by weight. Refer to the Service Manual, SENR5664, "Refrigerant System - Charge" section in Testing and Adjusting.
* After the system is charged and operated for a minimum of ten minutes, perform a performance check. Refer to "Performance Checks for the Air Conditioning System" section.
