What is the use of thermal relay relay is the thermal relay?
As the thermal relay action process takes a long time, it can not be used for short circuit protection, can only be overload protection. Thermal relay symbol; new standard (after 92 years): FR; old standard: RJ
Thermal relay is mainly used for overload protection, the principle is the overload current through the thermal components, so that bimetal heating bending to promote the action mechanism to drive contact action, which will disconnect the control circuit to achieve power, play the role of overload protection.
Mainly used to overload the motor overload protection, the motor overload, the running current will increase, the current through the thermal components, the bimetal heating bending to promote the action mechanism to drive the contact action, so the motor control circuit off to achieve Motor power off.
