An overload device that employs a bimetal strip as the actuating element. The bimetal strip consists of two metals bonded together. When heated, the bimetal strip will bend due to the different coefficients of linear expansion of the two metals. The bending operates a set of contacts that automatically removes the affected load from the source of electrical power
The adjustable current value allows the thermal overload relays to be set to the full-load current shown on the motor rating plate. This is the current range of the thermal component that can be adjusted to the desired trip point. The trip class is the maximum time in seconds at which the thermal overload relays will trip when the carrying current is at 600% of its current rating.