The ZB30 Series Bypass-Isolation Transfer Switches are the solution when interruption of power during service or testing is not acceptable. Consisting of two major modules-the Automatic Transfer (ATS) and the Bypass/Isolation Switch - the ZB30 Series incorporates the rugged construction of all our ZT30 Series automatic switches with a quick make/quick break bypass switch manual load transfer handle (for standard and delayed transition only) and our control/interlock system, which consists of both mechanical and electrical interlocks.

The bypass uses normal failure sensing and a time delay to start the engine automatically if a failure occurs when the ATS has been removed for service, which can be done without disturbing the load.

Configurations

ZB3ST - Standard (Open) Transition
The Zenith ZB3ST Bypass/Isolation transfer switch is used in general and mied load applications.

ZB3DT - Delayed Transition
The Zenith ZB3DT Bypass/Isolation transfer switch has an adjustable time delay in the centered "off" position. This delay allows motor loads to coast down and transformer field to decay; ensuring inductive loads are re-energized after transfer with only normal inrush starting currents.

ZB3CT - Closed Transition
The Zenith ZB3CT Bypass/Isolation transfer switch is used in critical/life safety applications where a "no break" transfer is desired during periodic testing and maintenance.