ZBTS(D)(CT) Bypass/Isolation ATS
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Zenith ZBTS/ ZBTSD/ZBTSCT Transfer/Bypass-Isolation Transfer Switches Introduction GE’s Zenith ZBTS Series Bypass-Isolation Transfer Switch consists of two major modules – the automatic transfer and the bypassisolation switches. The automatic transfer switch module is GE’s proven Zenith ZTS Series, built in ZTS, ZTSD or ZTSCT configuration and constructed for rugged, reliable operation. The same components – heavy-duty silver alloy contacts, rugged drive mechanism and silver plated bus bar inter-connections are used throughout the ZBTS Series. Features and Benefits GE’s design requires no additional load break contacts which cause load interruption during bypass-isolation functions. The bypass-isolation switch contacts are out of the system current path except during actual bypass operation. Therefore, they are not constantly exposed to the destructive effects of potential fault currents. The Source 1 (normal), Source 2 (emergency) and load are connected between the automatic transfer switch and the bypass-isolation switch through solidly braced isolating contacts that are open when the automatic transfer switch is isolated. All current carrying components provide high withstand current ratings in excess of those specified in UL 1008 standards. Description and Operation The bypass section is a ZTS switch provided with a quick make/quick break manual load transfer handle and GE’s control/interlock system consisting of both mechanical and electrical interlocks. The bypass switch is equipped with normal failure sensing and a time delay to start the engine automatically if the ATS has been removed for service. The modules are mounted in a compact enclosure and completely interconnected requiring only Source 1 (normal), Source 2 (emergency) and load cable connections. Once installed, no cables need to be removed to isolate the transfer switch module for maintenance or inspection. The automatic transfer switch may be withdrawn for testing or maintenance without disturbing the load. The transfer switch module has three positions: 1. Automatic/Connected: The transfer switch is carrying the load, and the bypass switch is in the open position. This is the normal operating position. 2. Test: The bypass switch is closed and feeding the load. The transfer switch has control power and may be operated for test purposes via the test switch on the enclosure door. The load is not affected during testing 3. Isolate: The transfer switch is withdrawn from all power and ready for maintenance. The load is served by the bypass switch. The Automatic Transfer Switch is installed on a draw-out mechanism, with electrical and mechanical interlocks for secure removal after load bypass. The ATS control/logic panel is mounted on the enclosure door and connected by a wire harness and multi-pin disconnect plugs. The transfer switch and/or the control panel may be tested, isolated and removed for maintenance without load interruption. The bypass-isolation switch module is the same basic design as the automatic transfer switch module and thus has the same electrical ratings. Manually operated, it features high speed, quick make/quick break contact action. The bypass-isolation switch has three basic positions: 1. Automatic: Source 1 (Normal) bypass contacts open, Source 2 (emergency) bypass contacts open. 2. Bypass Normal: Source 1 (Normal) bypass contacts closed, Source 2 (emergency) bypass contacts open. 3. Bypass Emergency: Source 1 (Normal) bypass contacts open, Source 2 (emergency) bypass contacts closed. Interlocks and Indicators Every ZBTS Series Bypass-Isolation Transfer Switch is supplied with all necessary electrical and mechanical interlocks to prevent improper sequence of operation as well as the necessary interlocking circuit for engine starting integrity. Each ZBTS Series Switch is furnished with a detailed, step-by-step operating instruction plate, as well as the following function diagnostic lights: • Source 1 (Normal) Available • Source 2 (Emergency) Available • Bypass Switch in Source 1 (Normal) Position • Bypass Switch in Source 2 (Emergency) Position • Automatic Transfer Switch in Test Position • Automatic Transfer Switch Isolated • Automatic Transfer Switch Inhibit • Automatic Transfer Switch Operator Disconnect Switch “Off” • Automatic Transfer Switch in Source 1 (Normal) Position • Automatic Transfer Switch

Application Notes: ZBTS & ZBTSD Model, Dimensions and Weights NEMA 1 Enclosed Ampere Rating Reference Figure Open Type ZBTSCT Model, Dimensions and Weights NEMA 1 Enclosed Ampere Rating Weight Reference Figure Application Notes Open Type All dimensions and weights are approximate and subject to change without notice. Special enclosures (NEMA 3R, 4, 4X, 12, etc.) dimensions and layout may differ. Consult the GE factory for details. Bypass Model product can not be ordered with inverted style. Special lug arrangements may require different enclosure dimensions. For certified drawings, contact...