Low voltage, high energy surge arrester for secondary applications

A surge arrester comprising:

• an insulative housing;
• a first metal oxide varistor in said housing, said varistor having a first facing surface in electrical and physical contact with a common electrode and a second facing surface in electrical and physical contact with a first outer electrode;
• a second metal oxide varistor in said housing, said varistor having a first facing surface in electrical and physical contact with said common electrode and a second facing surface in electrical and physical contact with a second outer electrode, said outer electrodes and said common electrode comprising conducting plates;
• spring means in said housing for imparting a compressive force against said varistors and said electrodes;
• conductors electrically connected to each of said electrodes and extending outside of said housing;
• and
• potting compound surrounding said metal oxide varistors and said electrodes in said housing.

A surge arrester comprising:

• an insulative housing;
• a first metal oxide varistor in said housing, said varistor having a first facing surface in electrical contact with a common electrode and a second facing surface in electrical contact with a first outer electrode;
• a second metal oxide varistor in said housing, said varistor having a fist facing surface in electrical contact with said common electrode and a second facing surface in electrical contact with a second outer electrode;
• spring means in said housing for imparting a compressive force against said varistors and said electrodes;
• conductors electrically connected to each of said electrodes en extending outside of said housing;
• potting compound surrounding said metal oxide varistors and said electrodes in said housing;
• and
• wherein said electrodes include raised portions forming electrical contacts for making electrical contact with said varistors.

A surge arrester for mounting inside a transformer enclosure on the neutral bushing stud, said arrester comprising:

• a plate formed of conducting material;
• a pair of metal oxide varistor disks, each of said disks having a first surface electrically connected to said conducting plate and a second surface facing away from said plate;
• a pair of electrical contacts, each of said pair of contacts being electrically connected to said second surface of a different one of said metal side varistor disks;
• an aperture formed through said conducting plate and disposed about the neutral bushing stud;
• and
• a pair of conductors, each of said pair being electrically connected to a different one of said electrical contacts.

A surge arrester comprising:

• an insulative housing;
• a first metal oxide varistor in said housing, said varistor having a first facing surface in electrical and physical contact with a common electrode and a second facing surface in electrical and physical contact with a first outer electrode;
• a second metal oxide varistor in said housing, said varistor having a first facing surface in electrical and physical contact with said common electrode and a second facing surface in electrical and physical contact with a second outer electrode;
• spring means in said housing for imparting a compressive force against said varistors and said electrodes;
• conductors electrically connected to each of said electrodes and extending outside of said housing;
• potting compound surrounding said metal oxide varistors and said electrodes in said housing;
• and
• wherein said common electrode includes three raised portions arranged in a triangular pattern for making electrical contact with said first metal oxide varistor and three raised portions arranged in a triangular pattern for making electrical contact with said second metal oxide varistor, said raised portions being formed substantially equidistant from the center of said common electrode.