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  • Electro-Motion is always proactive in scheduling and completing preventative maintenance. Their follow up and documentation is excellent. They are very responsive to my requests for additional information and never complain when I need emergency service.

    Dave Wiggins
    Facility Manager
    Sacrum Services

    Elevator Pre-Signal Relays

    August 21, 2014

    Are you in the planning/design phase of retrofitting your elevator systems to be in compliance with current ASME codes and standards? If so, these new elevator systems require the installation of pre-signal relays. Why is this?

    With old elevator controllers, it didn't matter if the Automatic Transfer Switch transferred when the elevator cars were moving. But now, when elevator controls are upgraded from relay logic to solid state controls, the cars can no longer be in motion when the Automatic Transfer Switch transfers between hot power sources. The solid state logic in the new elevator controllers cannot handle this and it can result in damage to the controller. To circumvent this problem, a pre-signal (a delay to transfer) is sent to the elevator controller prior to transfer, allowing cars to reach the nearest floor and open their doors. The system resets after the Automatic Transfer Switch transfers and the cars are then ready to move again.

    Electro-Motion is experienced at installing pre-signal relays in the San Francisco Bay Area to address this issue. If you need to have pre-signal relays installed, call us today at 650-321-6169.


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