06184459 is referenced by 20 patents and cites 82 patents.

A transformer is disclosed, including a tank housing a transformer core/coil assembly, a dielectric insulating fluid surrounding the core/coil assembly, the fluid comprising a vegetable oil, an antioxidant dissolved in the oil, and a low temperature additive blended into the oil, wherein the fluid defines a headspace above the fluid. The preferred embodiment includes an oxygen absorbing material contained in the tank and in contact with gases in the tank but isolated from contact with the dielectric fluid, the tank including an opening and a sealed plug in the opening, such that the oxygen absorbing material can be replaced through the opening upon removal of the sealed plug, and further includes a gas permeable polymer container sealed against the opening for supporting the oxygen absorbing material and an indicator in gas contact with the headspace and visible from outside the tank for indicating the presence of oxygen in the headspace.

Title
Vegetable oil based dielectric coolant
Application Number
9/276191
Publication Number
6184459 (B2)
Application Date
March 25, 1999
Publication Date
February 6, 2001
Inventor
Edgar Howells
Greendale
WI, US
Kevin J Rapp
Oak Creek
WI, US
Gary A Gauger
Franklin
WI, US
Richard A Harthun
Burlington
WI, US
Jerry L Corkran
Waukesha
WI, US
Charles Patrick McShane
Waukesha
WI, US
Agent
Fish & Richardson P C
US
Assignee
Cooper
TX, US
IPC
H01F 27/08
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