Application

In isolated phase metal enclosed bus ducts as circuit isolator. For phase reversal operation in pumped storage stations.

Features

  • Metal enclosed telescopic disconnect switch
  • Phase isolation
  • Manual or motor ganged operation in multi-pole assemblies
  • Mechanical and or electrical interlocking
  • Isolating gap visible through contact viewing window
  • Designed, manufactured and tested to ANSI standards
  • Open gap withstands full BIL level
  • Suitable for use in self-willed or forced air cooled bus systems

Construction

The switch has a tubular conductor with two fixed aluminum sections and a moving tubular copper bridging contact. Current transfer is made through two sets of spring loaded silver plated contact fingers equally spaced around the diameter of the conductor. The fingers are held in place on the periphery of the conductor by stainless steel retaining rings, or garter springs.

At each support point the conductor is mounted on four radially displaced porcelain insulators in a tubular weather tight and dust-tight aluminum housing. The housing also offers mounting feet for vertical or horizontal mounting.

Access to the inside of the switch is obtained by removing the contact viewing window and/or the covers joining the switch to the connected bus.

Silver plated terminal pads are provided each end of the conductor to accommodate flexible connectors going the switch to the connected bus. Similar provision is made for connecting the switch enclosure to the connected bus enclosure.

A removable grounded metal barrier in the open switch gap may be supplied on request.

Operating Mechanism

Little effort is required to operate the switch and manual or motor operating mechanisms are available for individual pole or ganged three pole operations.

The operating force is transmitted by means of an insulated shaft to track and pinion gear mechanism connected to the moving contact. This ensures positive operation of the switch movement.

Blade Type Disconnect Switches

NOTE 1. ONE MINUTE POWER FREQUENCY WITHSTAND (kV)
NOTE 2. 1.2 X 50 MICROSECOND IMPULSE WITHSTAND (kV)
NOTE 3. SWITCHES ARE AVAILABLE WITH ARC CHUTE TO INTERRUPT MAGNETIZING CURRENT UP TO 28kV AND 30 AMPS.

Telescopic Type Disconnect Switches

  1. Operating shafts
  2. Support insulator
  3. Main conductor
  4. Aluminum enclosure
  1. Moving contact
  2. Fixed contacts
  3. Viewing window
  4. Mounting brackets

NOTE 1. ONE MINUTE POWER FREQUENCY WITHSTAND (kV)
NOTE 2. 1.2 X 50 MICOSECOND IMPULSE WITHSTAND (kV)