... is made between the metal casing of the temperature controller and the metal part of the grounding device.12. ... -wave oven, electric heating coffee pot, electric cooker, refrigeratory, air-conditioner, laminator, heater of auto seat. Precautions:1.When adopting ... cover is prohibited during installation.3.Liquid inleakage into the controller, crackle in the casing and unauthorized change of external ...