Abstract: A surge arrester particularly suited for secondary side protection of distribution transformers, includes a low-voltage, high-energy varistor disk having electrodes disposed about its facing surfaces and a self-compressing spring clip with spring arms disposed about the varistor to provide the compressive force necessary to maintain good electrical contact between the electrodes and the varistor. The arrester includes terminals for electrically interconnecting the electrodes with the electrical apparatus being protected by the arrester. The arrester further includes a dielectric coating substantially enveloping the varistor, the spring clip and electrodes. The arrester requires no other housing. The spring arms may be made in a variety of configurations and shapes and may be interlaced with adjacent spring clip and varistor subassemblies so as to form three-phase or other multi-pole arresters.

Abstract: A fuse is provided for protection of high current power distribution equipment, such as transformers. The fuse includes a dual function fuse element having a solder pot which permits fuse opening in response to long-term current overload conditions, and a minimum cross-section wire portion for short circuit opening. The fuse element is enclosed within a tube, and the tube is received within a housing. The tube is closed off on one end thereof with a dual size button, which size is selectable for reception into the housing.

Abstract: A surge arrester for mounting on a transformer having two line-potential terminals and a neutral terminal. The arrester includes two high energy, low voltage metal oxide varistor disks, each MOV disk having one side connected to an electrode that is electrically connected to one of the line-potential terminals and having the other side of the MOV disks electrically connected to a neutral electrode that is electrically connected to the neutral terminal of the transformer. The MOV disks shunt any current surge to ground upon the application of a predetermined voltage across the disks. In the preferred embodiment, the electrodes and MOV disks are housed within a thermoplastic elastomer housing filled with a potting compound of a resilient elastomeric material. The potting compound completely insulates and seals the electrical connections and MOV disks.