Motor protection switches are specially developed protection and manual control elements for engines. A motor circuit is manually opened and closed over the buttons on the switch with the engine protection switch and the protection unit is protected thermal and magnetically thanks to the protection unit. In addition, a metal unit, which provides thermal protection in motor protection switches, provides protection by cutting the circuit as a result of overheating in other phases in case of phase loss.

Thermal relays are the elements used with contactors to protect motors against overload currents. It contains bimetals of each phase, and in case of excessive current in the system, the bimimetals heats up and disable the motor through the contactor to which it is connected. Since thermal relays do not provide any protection against short circuits, a magnetic protection element should be used in the circuit. Thermal relays provide protection through bimetal and protect the circuit by opening the circuit with overloading effect in the other 2 phases in case of phase loss in the system.

Why Sigma Thermal Reliefs Should Used?

Sigma thermal relays produced according to TS EN 60947-4 1 can be used depending on contactors, as well as independently with the 35 mm Ray assembly adapter. Sigma Thermal Relays offer the possibility of manual or automatic activation with adjustable nominal current. It is produced with 1no+1NC auxiliary contact in 10A opening class.