What are the reasons for the constant temperature and humidity test machine compressor not cooling?

As the operators of the industry occasionally encounter the situation that the constant temperature and humidity test chamber is not cooled, in order to let the practitioners understand the performance of the equipment more clearly and in detail, Shanghai Huanqi Test Equipment Factory will share and solve the problem caused by constant temperature and humidity. The test machine compressor does not cool the technical solution.

Reason one:

1. Since the temperature is not maintained, observe whether the refrigeration compressor can be started during the operation of the test box, and the compressor can be started during the operation of the environmental test equipment, indicating that the electrical circuit from the main power supply to each compressor is normal, and the electrical appliance There is no problem with the system.

2. Touch the exhaust and suction lines of the R23 compressor of the main unit by hand, and find that the temperature of the exhaust line is not high, and the temperature of the suction line is not low (not frosted), which also explains the host group. The (R23) refrigerant is lacking.

Reason 2: 1. There is no problem with the electrical system. Continue to check the refrigeration system. Firstly, the exhaust and suction pressures of the low-temperature (R23) compressors of the two groups of refrigeration units are lower than the normal values, and the suction pressure is evacuated, indicating that the refrigerant capacity of the main refrigeration unit is insufficient.

2. The cause of the failure has not been determined. The cause of the failure is further confirmed by the control process of the test chamber. The test chamber has two sets of refrigeration units.

3. One main unit and the other auxiliary unit. When the cooling rate is large, the two sets of units work at the same time. In the initial stage of temperature maintenance, the two sets of units still work at the same time. When the temperature is initially stabilized, the auxiliary unit stops working, and the host group maintains the temperature stability. If the host group R23 leaks, the cooling effect of the host group will be small. Because the two units work at the same time during the cooling process, there is no temperature stability, and the cooling rate is indicated to decrease. In the temperature maintenance phase, once the auxiliary unit stops working, the main unit has no cooling effect, and the air in the test box will rise slowly. When the temperature rises to a certain level, the control system will start the auxiliary unit to cool down and lower the temperature to the setting. Near the fixed value, then the auxiliary unit stops working again. If it is repeated, there will be a malfunction.

At this point, it has been confirmed that the production failure of the constant temperature and humidity tester is caused by the leakage of the refrigerant R23 of the low temperature (R23) stage unit of the main unit. The leak detection of the refrigeration system was carried out by a combination of a leak detector and soapy water, and it was found that the stem of a hot gas bypass solenoid valve was cracked. Replace the solenoid valve, refill the system with fluorine, and the system is operating normally.

Summary: As can be seen from the above, the analysis and judgment of the fault phenomenon is basically easy and difficult. First, the "external" and "inside", first "electrical" and then "refrigeration" are analyzed and judged. Familiarity with and understanding of the principle and working process of the test chamber is the basis for analyzing faults to determine faults.

Of course, if you encounter more complicated technical problems, we still recommend that you contact the technicians of the equipment manufacturer for repair and maintenance to avoid unnecessary losses.

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