Cooper Industries, Inc.

Jeffrey J Kester

Jonathan J Woodworth

Thomas C Hartman

Gary A Gauger

Stephen P Johnson

David R Miller

Ross Stuart Daharsh

Lisa Carol Sletson

Stanley S Kershaw

Robert C Olen

Sherri J Cuthbertson

An improved surge arrester includes metal oxide varistors in series with spark gap assemblies arranged such that the MOV elements conduct the low magnitude, steady-state current through the arrester along a path that is separate and distinct from the path through which impulse current is conducted during an overvoltage.

Surge arrester having controlled multiple current paths

A composition for an insulating collar of a metal oxide varistor, with the composition being applied as a slurry to a green varistor in an unfired state along its periphery for enhancing the varistor's energy handling capability in a fired state, the composition having, in various combinations, a plurality of oxide compounds, including manganese dioxide, cobaltic-cobaltous oxide, nickel oxide, tin dioxide, chromic oxide, bismuth oxide, antimony trioxide, and zinc oxide. Moreover, a method of applying the slurry onto the unfired varistor and firing the coated green varistor in a single step.

Insulating coating

A fail-safe, non-fragmenting surge arrester includes a liner having outlets formed in the walls thereof for venting ionized gases generated within the liner by internal arcing. The vented ionized gas forms a lower impedance path for the current which is thereby shunted around the failed internal components, preventing the generation of internal pressure which could otherwise cause a fragmenting failure mode of the arrester. The internal components include stacked varistor elements and may include an internal fuse link electrically in series with the varistors.

Fail-safe surge arrester

Growing community of inventors

Olean, NY, United States of America

Jeffrey J Kester