Product Spotlight: Lake Shore Electric’s VB Series Automatic Transfer Switch

Lake Shore VB Series ATSLake Shore Electric offers a Vacuum Breaker (VB) Medium Voltage Automatic Transfer Switch for power generation applications requiring dependable transfer of loads to an emergency power source in the event of normal source failure.  The VB Series transfer switch is offered in fixed or draw-out designs, and suitable for use as service entrance equipment.

VB Series Medium Voltage Automatic Transfer Switches utilize two electrically and mechanically interlocked vacuum circuit breakers. Each breaker, whether fixed or draw-out, utilizes a two-step stored energy mechanism.  The breaker features a 3-Cycle (50ms) interrupting time, with mechanical endurance up to 20,000 operations.


  • Available in 600A, 1200A, 2000A, and 2500A with short circuit ratings up to 40kA.
  • Equipped with spring charging motor, manual charging handle, manual mechanical close/open push-buttons and stored energy operators.
  • Open/closed mechanical position indicators and spring charged/discharged indicators.
  • Microprocessor-based logic. The MP7650 ATS controller is robust and highly dependable.
  • Overcurrent protection is integral to the vacuum breaker, negating the need for separate overcurrent protective relays.
  • Safe manual operation of the transfer switch, under load. Manual operators are permanently installed to facilitate testing and maintenance.
  • Optional configurations and accessories include Closed Transition, Generator Differential Protective Relays, Surge Suppression and Digital Meters.
  • Custom configurations are available to provide close-coupling to bus duct or existing switchgear.

2 thoughts on “Product Spotlight: Lake Shore Electric’s VB Series Automatic Transfer Switch”

  1. Is it possible to keep a “behind the meter” combined heat and power generator connected when the transfer switch disconnects municipal peer source and switches to emergency generator(s)?

    • Hi Cameron, it is difficult to answer your question without seeing a schematic of your power systems’ arrangement. I encourage you to reach out to your local representative for Lake Shore Electric, to consult and arrive at a potential solution.


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