Housing insert for receptable seat

Abstract

An electrical device, in particular a fuse, circuit breaker or the like, comprises a housing having extending therefrom a projection, together with two conductive pins for connecting the device to an external circuit. A receptacle for accommodating the device has a wall provided with a seat and also with two holes through which the device pins pass when the device is inserted in the receptacle. A fitting is releasably accommodated in the seat and is able to accommodate the entrance therein of the projection to enable the device to be fully inserted. If an attempt is made to insert in the receptacle a different device provided with a projection that cannot enter the recess in the seat, the device cannot be fully inserted. However, the receptacle can be conditioned to accept the different device by inserting in the seat a different fitting having a different recess which will accommodate entrance of the projection of the different fitting. Fuses or circuit breakers of different current ratings are provided with projections of different shapes and/or sizes, whereby a receptacle provided with a particular seat will accommodate fuses or circuit breakers of a current rating equal to or greater than a value corresponding to that seat, but will not accept fuses or circuit breakers having a current rating less than that value.