Companion II Back-up Current-Limiting Fuse

Eaton's Cooper Power series Companion ll fuse is designed to be conveniently applied as an add-on, back-up, current-limiting fuse. The Companion II back-up fuse will interrupt high fault current and at the same time, limit the amount of energy that is let-through to the protected equipment. This fuse is designed to be applied in series with an expulsion or other type of weak link fuse. This series connected fuse must be capable of interrupting both excessive overload currents and low to intermediate fault currents up through the minimum interrupting rating of the Companion II fuse.

If the expulsion fuse is applied within the recommended guidelines, enough current will be let-through to melt the expulsion fuse. When the expulsion fuse is in a cutout, the resulting drop open action provides, in any fault situation, a positive blown fuse indication for operating personnel. The majority of faults on distribution systems are of low magnitude (such as transformer overloads or incipient faults), and normally only the lower cost expulsion fuse melt and clear the fault.

Eaton designs its Cooper Power series K-Limiter fuse to be conveninetly applied as an add-on, back-up, current-limiting fuse and as an extension of the NX Companion II fuse. It's designed to interrup high magnitude fault currents while limiting the amount of current and energy let-through to the transformer.