Folding Vertical Break Switch – VG1

Robust & Reliable

The Folding Vertical Break is designed with a simplicity that makes it reliable and easy to operate and maintain.

All the mechanical transmission components are accessible from outside the current path. There are no parts hidden inside the conductors.

Twin gear-set/pull-rod assemblies provide easy adjustment and stability.

All parts are fabricated from extruded aluminum or machined from solid billet materials, such as 304 stainless steel and hard drawn copper.


Compact design

  • The height of the blade in the open position is only 50% of a comparable conventional vertical break disconnector. Therefore, crossing structures and/or bus may be lower as well. Because of the lower height, the FVB is less sensitive to wind and earthquakes.;
  • The Folding Vertical Break or Knee type disconnect switch is a much better balanced system than a conventional vertical break, providing smoother and faster operation with less mechanical stress in the transmission chain.
  • In the closed position, under severe wet snow or ice buildup, the added weight on each half-blade section self-compensates each other. As a result, the added load (weight) on the blade does not increase the operating effort, making the FVB the best solution for rugged climate.
  • The contact pressure is provided by well proven spring-loaded contact fingers. The mechanically actuated jaw systems of other semi-pantographs is not necessary.

Easy inspection/maintenance

  • The gear-sets are doubled for greater reliability. Made from aircraft grade high strength aluminum. It has been tested for 2 000 reliable cycles. Contrary to the trend, EMSPEC chose not to hide the mechanical transmission inside the tube of the conductors. Therefore, this important function is easily accessible for inspection or maintenance.
  • All current transfers are based on our well-proven rotating contact with multiple spring-loaded fingers. The contact fingers are the same and fully interchangeable with the ones used on our vertical break knee type, our double break and center break disconnect switches.
  • The same contact parts are used at the hinge, the knee and the jaw.

Dimensions & Technical Data

  • Dimensions are based on ANSI TR insulators except for 420 kV* and 550 kV*.
  • IEC ratings and dimensions are available upon request.
En (kV)123145169245362420*550*
BIL (kV)5506507509001 0501 3001 4251 550
A1 7501 9002 1002 7003 0003 5003 8504 000
B2 5002 6502 8503 5503 8504 3504 7005 193
C1 4501 6001 8002 3002 6003 1003 4503 978
D1 5231 7521 9552 4652 7703 1253 5833 783
E2 4802 7843 0873 7944 2494 8545 4875 962
In (A)up to 3000up to 3000up to 3000up to 3000up to 3000up to 3000up to 3000up to 3000
Icc (kA peak)up to 163up to 163up to 163up to 163up to 163up to 163up to 163up to 163
Icc (kA rms)up to 63up to 63up to 63up to 63up to 63up to 63up to 63up to 63

For other ratings consult factory

  • Parallel or perpendicular grounding switch
  • Manual or motor operator
  • Mechanical, electromagnetic, electrical and trapped key interlock system
  • Arcing horns or High speed whips
  • Silver inlays or silver plating

This brochure provides a brief introduction. EMSPEC reserves the right to make changes at any time, without notice.

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