Back To Basics: Selecting The Right Power Supply

A basic door control system may be comprised of a power source, wiring which connects the system elements and a locking device. It could also be several locks and controls. Or the system power supply may have multiple outputs, supplying locks and...


Plug-in power supplies are plug-in transformers with additional circuitry inside the enclosure to rectify, filter and regulate the voltage to the desired DC (Direct Current) voltage.

Power supplies may also be connected to line voltage by means of a line cord.

The same constraints which apply to the wall mount transformer and line cord operated equipment also apply to the wall mount power supply.

According to the National Electric Code (NEC), receptacles found above dropped ceilings should not be used for plug-in power or line cords. You or your customer should not have a receptacle installed for permanently powering a system above a dropped ceiling. Doing so is a violation of the electric code, and if ever a fire or personal injury occurs, or an electrical inspector finds it, you may be subject to censure or lawsuits.

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