Analysis of the low temperature and low temperature damp heat aging box slow cooling solution - Database & Sql Blog Articles

The high and low temperature damp heat aging test chamber is also called constant temperature and humidity test chamber, high and low temperature damp heat test chamber, damp heat aging box, which mainly provides constant damp heat and high complexity for testing of electronic parts, industrial materials and finished products in all aspects of R&D, production and inspection. Low-temperature alternation and other test environments and test conditions are applicable to various industries such as electronics, telecommunications, chemicals, hardware, rubber, toys, etc.

Under normal circumstances, the high and low temperature damp heat aging test chamber will reduce the temperature to the corresponding value according to the set time, but because the equipment is used for too long, or the operation may be improper, it will cause the low temperature and low temperature alternating heat and humidity test box to slow down. Now on how to deal with this question, conduct a skill discussion.

Factor one:
1. There is no doubt about the gas system and continue to check the refrigeration system. Firstly, the low-pressure (R23) compressors of the two groups of high-low temperature damp heat aging tanks have lower exhaust and suction pressures than normal, and the suction pressure is convulsive, indicating that the refrigerant capacity of the main refrigeration unit is lacking. .

solution:

Because the temperature can not hold, investigate 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, the electrical system There is no doubt about the aspect.

Factor two:
1, determine the cause of the disease, contact high and low temperature damp heat aging box

The handling process further acknowledges the cause of the disease, and the test chamber has two sets of refrigeration units.
2. The main unit and the other auxiliary unit. When the cooling rate is large, the two groups work together. In the early stage of the temperature persistence period, the two units still work together. When the temperature starts to stabilize, the auxiliary unit is stopped, and the temperature is stabilized by the host group. If the host group R23 leaks, the cooling effect of the host group will be small, because in the process of cooling, the two units work together, so there is no appearance of temperature stability, and the cooling rate is indicated to decrease. During the temperature persistence, once the auxiliary unit stops working, the host group has no cooling effect.

High and low temperature damp heat aging box

The air inside will rise slowly. When the temperature rises to a certain extent, the control system will start the auxiliary unit to cool down, lower the temperature to the set value (-55 °C), then assist the unit to stop the operation, so repeat the sleeve valve. tube.

solution:

It is acknowledged that the cause of the production is that the refrigerant R23 of the low temperature (R23) stage of the main unit is leaking. The leak detection of the refrigeration system was carried out by means of a leak detector and soapy water. It was found that the stem of a hot gas bypass solenoid valve cracked a slit of about 1 cm. Replace this solenoid valve, the system is filled with fluorine from the head, and the system works normally. As can be seen from the above, the analysis and discrimination of the appearance of the problem is basically difficult, first "outside" and then "inside", first "electrical" and then "cooling" the head of the analysis and discriminating, know and Knowing the principle and operation process of the test chamber is the basis for analyzing the problem of fault diagnosis.