Thermal Overload Relays offer economical and reliable protection for motors in the event of overload or phase failure. The devices have trip class 10.
The TORs are three pole relays with bimetal tripping elements. The motor current flows through the bimetal tripping elements and heats them directly and indirectly. In case of an overload (overcurrent), the bimetal elements bent as a result of the heating. This leads to a release of the relay and a change of the contacts switching position.
Manual Motor Starters
Manual motor starters (MMS) are protection devices for the main circuit.
They combine motor control and protection in a single device. MMS are used mainly to switch motors manually ON/OFF and protect them
and the installation fuse less against short-circuit, overload and phase failures. Fuseless protection with a manual motor starter saves costs, space and ensures a quick reaction under short-circuit condition, by switching off the motor within milliseconds.