Bimetal overload relay

摘要

A U-shaped heater unit is surrounded by a U-shaped bimetal, the legs of which move in response to temperature variations. The motion of the bimetal is conveyed through a wall by a slidable pin which acts to rotate an L-shaped compensator element. This rotation lifts a link element which operates a switch when the trip point is reached. A reset mechanism includes a plunger which when manually depressed rotates a reset arm first in one direction to reset the switch after it has been tripped and then in the opposite direction to a neutral station in which it will not reset the switch. The reset mechanism thus cannot be defeated by jamming the plunger in its fully depressed position.