QINSUN 's trial helps you analyze the reasons for the cooling of high and low temperature test chambers
Many customers encounter high and low temperature test chambers during the use of high and low temperature test chambers Slow, Wen can not fall, the temperature is less than -40 degrees, etc. The high and low temperature test chamber will be reduced to the corresponding value according to the set time, but because the equipment is used too long, or when the operation, it will cause the high and low temperature box to cool down slowly, how to solve this problem now, Discussion on technology.
1. Undefined causes, the control process of the combined test further confirms the cause of the failure, the high and low temperature test chamber has two sets of refrigeration units.
2. One is the host group, and the other auxiliary unit, when the cooling rate is large, the two sets of units work at the same time, at the beginning of the temperature maintenance stage, the two sets of units still work. The temperature is initially stabilized, and the auxiliary unit stops working, and the host group maintains the stability of the temperature. If the host group R23 leaks, the cooling effect of the host group will not be high. Due to the cooling process, the two units work at the same time, so there is no temperature and stable phenomenon, but indicates that the cooling rate is lowered. In the temperature maintenance stage, once the auxiliary unit stops, the host group has no cooling effect, the air in the high and low temperature test chamber will rise slowly. When the temperature rises to a certain extent, the control system will start the auxiliary unit to cool down, drop the temperature To the vicinity (-55 degree), then the auxiliary unit stops working, so repeated, there will be a failure. At this point, the reason for the production fault has been confirmed is the refrigerant R23 leakage of the low temperature (R23) unit unit of the host group. The refrigeration system is checked, the method of combining the leak detector and soapy water, and the valve stem of the hot air bypass solenoid valve is found to crack about 1 cm. Replace this solenoid valve, re-fluorine the system, and the system is operating normally.