Automatic Transfer Switches (ATS)

<p>Open-transition transfer devices: When the source fails, the open-transition transfer device opens the connected source before engaging the new source. This causes an interruption of power for a small period. </p><p>Fast closed-transition transfer devices: Operates similar to the Open-transition transfer devices but uses a 'make-before-break' switching action on return of original source by paralleling both sources for approximately 100 milliseconds. This device limits power interruption upon returning to mains utility. </p><p>Soft closed-transition devices: Operates like an open-transition transfer switch but when transferring power from one generator to utility, the control system will synchronize the sources and gradually transfer the load</p>