Incoming test for thermal switch includes temperature test under No-Load, mock-up test under load, functional test in applications and appearance inspection. Since mock-up test, functional test and appearance inspection can be easily done in the customers’ factories, we will only explain how to conduct temperature test under No-Load here.
1. Put the thermal switch inside of a test oven. The air flow speed of the oven needs to be over 200m/min
2. The measuring thermal couple should be as close to thermal switch as possible. An indicator of showing ON/OFF should be provided. The current flowing through thermal switch is less than 0.01A
3. Increasing the air temperature inside of the oven slowly. When air temperature increases to the 10C lower than the bottom tolerance limit of rated temperature value, the further temperature increasing speed has to be controlled at 0.5K/min.
4. When the temperature reaches the tolerance of thermal switch, the bimetal will actuate the contact and cut the circuit off. After that, the operator can open the cover of test oven and let the temperature decrease down. Then, the thermal switch will turn ON again.