Electrical Schematic – Motor Protection – Against Overloads – Overtorque Relay

In addition to thermal protection by relays or PTC probe, these ensure protection of the drive chain in the event of rotor locking, mechanical seizing or inching.
These, unlike most overload relays, have no thermal memory. They have a set operating time (adjustable current threshold and timing).
An overtorque relay can be used to protect motors against overload when their starting process is long or very frequent (e.g. inching).