Structural Features

Cores - The magnetic cores of Uptegraff Power Transformers are made of high-permeability, grain oriented steel. All cores utilize step-lapped laminations for minimum loss, sound level, and exciting current.

Coils - The general coil construction is elliptical in shape (layer wound). Round (circular) or disc wound coil construction is available upon request. Both copper and/or aluminum windings are available. The Uptegraff Company pioneered the use of aluminum conductor in transformer windings, with eminently successful results.

Insulations - Like most manufacturers, Uptegraff uses thermally up-graded kraft paper insulation in liquid filled units. A "B" stage epoxy is applied to the insulation in a diamond pattern in order to assure minimum coil distortion under short circuit. Class "H" (Aramid) insulation is also available upon request.

All Uptegraff dry-type transformers contain sheet insulation consisting largely of Aramid fibers which have a class H thermal rating. This material is supplemented with polyester-type resin impregnation.

Dielectric Fluids - Uptegraff liquid immersed transformers can be provided with acid-refined, filtered and deaerated mineral oil (either Type I or Type II in accordance with ASTM Standard D 3487); vegetable oil; less-flammable silicone or R-Temp® fluids or non-flammable fluid alternatives. All liquid immersed transformers can be used indoors or outdoors as long as they are installed in accordance with the provisions set forth in the NEC and/or any local codes which may take precedence or be more restrictive. All Uptegraff liquid immersed transformers are shipped with dry nitrogen in the gas space above the liquid.

Enclosures - The standard transformer tank or enclosure is made of reinforced ASTM A-36 carbon steel plate. As an option for corrosive environments, the tank can be provided using stainless steel or copper bearing steel plate. Enclosures for dry type transformers can also be provided in aluminum or fiberglass.

For liquid filled transformers, a variety of radiator configurations can be provided depending on cost, size and site conditions. They include tubular style, corrugated style (standard is 2 1/4" centers and can be varied to 5" centers for ease of cleaning and/or painting), panel or plate type or heavy plate type.