Resetable over-current and/or over-temperature protection system

Abstract

An electrical protection system, which can be connected between an electrical power supply and an electrical load, firstly includes a switch switchable between a normal state in which the switch is electrically connected in series between the power supply and the load such that an operating current passes through the switch and the load, and a fault sate in which the switch is disconnected with the load such that no current passes through the load. The switch switches to the fault state in an over-current or an over-temperature situation. The system further includes a controller operable in an open state when the switch operates in the normal state, in which state the controller is electrically disconnected from the power supply such that no current passes through the controller, or a closed state when the switch operates in the fault state, in which state the controller is electrically connected in series between the switch and the power supply such that a self-holding current passes through the switch and the controller. The controller operates to automatically set the switch to the normal state when the self-holding current is off.