Electrical Wiring for PQ

While it is true that some things that effect sensitive electronics come from the outside world, many originate inside the facility itself. For example, the wiring in your building was probably designed to serve motor and lighting loads, not computers and printers. There are a few things you can do to help the system better serve these types of loads.

Look for "Noisy" Loads - Some pieces of electrical equipment are electrically noisy. This means that they distort the power on your circuits. You can see the results of this type of noise on a TV when someone in the same room is operating a hair dryer. The TV signal is distorted and snow or lines appear on the screen. You can find electrically noisy equipment in your facility by tuning a portable AM radio to the low end of the dial where there is no station, and walking through your building. The static on the radio will grow louder as you approach the noise generator. Isolate sensitive equipment from these culprits.

Don't Undersize Neutrals - The NEC allows the derating of the neutral for three-phase circuits. If you are installing three-phase circuits for electronic systems, tell the contractor to make the neutral conductor double the size of the other conductors. With today's microprocessor-based equipment, the neutral will carry more current than the energized conductors. This poses a threat of failure or worse if the neutral is not properly sized.