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Fostoria Bushings and Insulators

PB-21

POWER BUSHING ASSEMBLIES 8.7kV CLASS, 95kV BIL, 10.25″ CREEP

Technical Specification

1. Application

  • Designed for transformers and special power apparatus applications.
  • Suitable for installations where the lower end of the bushing operates under oil in a liquid-filled transformer.

2. Construction and Materials

  • Porcelain: Manufactured from high-quality electrical-grade wet-process porcelain, gray glazed over the entire surface for enhanced durability.
  • Top Skirts: Specifically designed for outdoor applications.
  • Spade Casting: Fabricated from pure copper, tin-plated, providing a minimum of 97% electrical conductivity.
  • Clamps and Washers: Constructed from nonmagnetic materials to ensure electrical integrity and mechanical stability.

3. Mechanical Design

  • Disc Springs: Maintain constant gasket pressure at the top terminal, compensating for thermal expansion and contraction of the copper stud.
  • Mounting: Designed for installation in a 63.13 mm (minimum) diameter hole.

4. Gasket and Sealing

  • Standard Gasket: Nitrile (Buna-N) gasket supplied as standard.
  • Optional Gasket: For assemblies requiring cork-rubber composition gaskets, add suffix “C” to the part number.
Diagram of a power bushing assembly designed for 8.7kV class applications, featuring specifications such as dimensions, part numbers, and clamp details.