1. First check whether the refrigeration compressor can be started during the operation. If it can be started during operation, it means that the electrical circuit from the main power supply to the constant temperature and humidity test chamber compressors is normal, then the electrical system can be eliminated. no problem. When there is no problem checking the electrical system, continue to check the refrigeration system.

2. Check a group of refrigeration compressors. If the exhaust and suction pressures of the low-temperature (R23) compressor are lower than the normal value, and the suction pressure is evacuated, this indicates that the refrigeration capacity of the main refrigeration unit is obvious. insufficient.

3. Touch the exhaust and suction lines of the R23 compressor of the main unit by hand. If the temperature of the exhaust line is not high, the temperature of the suction line is not low (no frost), which also explains The lack of R23 refrigerant in the host group.

4. 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 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 drop and stability.

5. 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 phenomenon that the temperature is stable, and the cooling rate is indicated to decrease.

6. In the temperature maintenance phase, once the auxiliary unit stops working, the main unit has no cooling effect. The air temperature in the constant temperature and humidity test chamber will rise slowly. When the temperature rises to a certain level, the control system will start the auxiliary unit again. After cooling down, the auxiliary unit stops working again. If it is repeated, there will be a phenomenon that the low temperature cannot be maintained.