ISOLATED PHASE BUSDUCT (SIS Bus Bar System)

Technical Comparison, Bus Duct System vs. SIS Bus Bar System

General description of a bus duct system :

  • A bus duct system has three (for LV application also four phases are possible) in a metal enclosure.
  • It is available as a segregated or non-segregated system.
  • The Rectangle copper or aluminum conductors are installed in the metal enclosure on insulators.
  • The conductor bars themselves are not insulated.
  • Such bus duct system is designed up to a voltage level of 36kV.
  • A system is built up by standard straight elements and 90 Degree elbows.
  • The Conductor bars could be separately insulated by a thin cast resin layer

SIS Bus Bar System :

  • The SIS bus bar is build up by individual insulated phases
  • each conductor itself is fully insulated by cast resin filled insulation paper
  • Has an entire earthing layer protected by additional cast resin layer and shrinking sleeve as final outer layer for indoor bus bars and a metal tube for outdoor busbars

SIS – Solid Insulation System

Electrical Rating Parameters:

  • System voltage up to 40,5 kV.
  • Rated current up to 6.500 A single system.
  • Double system up to 12.000 A.
  • Partial discharge free up to 1,5x phase to ground voltage

System Specific Benefits :

  • Compact design
  • Low space requirement
  • Small bending radius
  • 3-dimensional geometric shape
  • No maintenance
  • Production Length 13 m x 3 m x 3 m

Design

  1. Aluminum or copper conductor.
  2. The main insulation consists of epoxy resin impregnated crepe paper.The impregnation process is performed under vacuum.
  3. Capacitive graded area – implementing of capacitive layers by using semi-conductive crepe paper.
  4. The last layer is grounded and ensure touch-safe bus bar.

Production Process

Indoor Bus Bar 

  • Paper insulated conductor, vacuum sealed by using a shrinking sleeve.
  • Drying process under vacuum.
  • Impregnation process conducted under vacuum.
  • Total process under temperature control.

Outdoor Bus Bar – Additional Steps

  • Indoor Bus bar covered by stainless steel tube.
  • Adding of outdoor material.

Multiple Busbar Connection

Performed with flexible connectors

  • Allows thermal compensation.
  • Compensating of installation tolerance

Connecting Sleeve

  • Fully insulated
  • Touch safe
  • Capacitive graded
  • Protection class IP45, higher classes on request

End Bus Bar Connection

  • Conductor end with flat terminal according DIN 42 206
  • Conductor end with round bolt
  • According to customer’s specification
  • Gas-tight connection to GIS switchgear
  • Metal flange fixed on the beginning of the grounded part of the bus bar
  • Connection by using contact bolts – standard
  • Customized design