Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Asea Brown Boveri Inc.

Andrew S Sweetana, Jr

Tapan K Gupta

Kenneth C Radford

William G Carlson

Frederick J Brown

Robert G Johnson

Gerald B Boyette

Joseph C Osterhout

Richard E Kothmann

Thomas H Putman

Charles H Carothers

Thomas P Basa

Nicholas J Stroud

A method of manufacturing a varistor utilizes preselected amounts of ZnO which are combined with specified amounts of additives including B, Na, Bi.sub.2 O.sub.3 and BaO to form a variety of compositions. Each composition is pressed into a disc. The disc is then sintered at a first selected temperature. Afterwards, the disc is annealed at a second selected temperature. The specific compositions disclosed render a varistor with improved high temperature performance when the annealing step is followed with a low temperature tempering cycle at approximately 250.degree. C.

Surge stability improvement of zinc oxide varistor discs

A method for producing varistors having high energy absorption. The high energy absorption is achieved by combining predetermined quantities of Bi.sub.2 O.sub.3, BaO, SiO.sub.2 and Sb.sub.2 O.sub.3 with ZnO to produce a mixture which is sintered to produce a varistor disc having high energy absorption.

High energy absorbing varistor

A varistor utilizing a disc of mainly ZnO in combination with preselected combinations of Bi.sub.2 O.sub.3, Sb.sub.2 O.sub.3, SiO.sub.2, MgO and CaO.

Very high energy absorbing varistor

A method for making a varistor disc with increased high temperature stability. The method includes the steps of formulating a mixture for the varistor disc, compacting the mixture to form a disc, sintering the disc at a first preselected temperature and cooling the disc at a predetermined linear rate. The predetermined linear rate and preselected temperature are selected to reduce nonequilibrium conditions which become 'frozen-in' as said disc is cooled.

Method for making varistor discs with increased high temperature

A fuse assembly for an electrical cutout is provided with capability for rapid arc extinction by a capsule of pressurized insulating gas being located within a fuse tube above the fusible element so that when the fusible element melts and an arc is produced, gas is released from the gas cylinder that quenches and cools the arc and also assists a spring loaded flipper mechanism in expelling a lower conductor from the fuse tube.

Fuse assembly, for a cutout, with accelerated arc extinction

A disconnector for lightning arresters is provided that incorporates a gas cylinder with a dielectric gas such as carbon dioxide which will be released upon an excess current and result in the extinguishing of the arc in the disconnector spark gap prior to danger of shattering of the arrester housing.

Electrical surge arrester and disconnector

A metal oxide type surge arrester is provided with a plurality of arrester blocks in series within a housing having, in addition to line and ground terminals at the extremities, a bushing providing a tap voltage terminal intermediate the series stack such as between the bottom two arrester blocks. The provision of the voltage tap and a shunt resistance in series with the ground terminal permits respectively detecting the voltage and the current of the arrester so that they can be compared and their phase relation observed to determine if the arrester blocks are maintaining a capacitive characteristic or have become resistive. In addition, several other methods of use of such an arrester for monitoring line voltage, energy absorption, fault current and the like are disclosed.

Surge arrester equipped for monitoring functions and method of use

A voltage limiting composition, actually a nonlinear resistor, especially suitable for use in a gapless surge arrester is disclosed herein. This composition includes a predetermined amount of zinc oxide as its primary ingredient and one or more specifically selected additives. All of these constituents are combined and sintered so that the composition displays a nonlinear exponent .alpha. at least equal to about 35 over the current range of 1 ma to 5000 amps and such that its energy absorption capability is at least equal to about 50 joules/cm.sup.3.

Voltage limiting composition and method of fabricating the same

The present invention discloses a modular reactor that increases the inductance per axial length by winding a conductor circumferentially about a central axis in a manner which results in radially extending columns which are sequentially wound in alternating radial order. The modules are constructed to allow them to be combined in either radial or axial juxtaposition and electrically connected either in series or in parallel.

Modular power system reactor

A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of selected alkali metal oxide of from about 0.003 mole % to about 0.2 mole %.

Voltage stable nonlinear resistor containing minor amounts of aluminum

A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of boron oxide of from about 0.005 mole % to about 0.25 mole %.

A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of boron oxide of from about 0.005 mole % to about 0.6 mole %, in combination with a total amount of at least one selected alkali metal oxide of from about 0.005 mole % to about 0.3 mole %.

Voltage stable nonlinear resistor containing minor amounts of aluminum,

A gapless surge arrester is disclosed herein and includes a porcelain outer casing and a stack of zinc oxide discs located within the casing for passing surge currents therethrough. Silicon dioxide, preferably sand, is provided between this stack in the casing for transferring heat from the discs to the porcelain outer casing as a result of the surge current and for absorbing fault energy where necessary by changing states.

Growing community of inventors

Bloomington, IN, United States of America

Andrew S Sweetana, Jr