Upon moving into the entire first floor of a high-rise building in Phoenix, Arizona a bank experienced computer interference problems in a section of the floor area. Our EMF measurements identified the secondary electrical feeds located in a transformer vault under the building as the source for the elevated magnetic field levels and subsequent computer interference. The bank management decided that mitigation was needed to eliminate the computer inference. Our team evaluated how much field reduction was necessary, developed a mitigation plan with changes to the wiring configuration and increases in the distance between the electrical raceways and the bank floor.
The client consulted with the utility provider, which verified the achievability of our design goal and technical specifications. The utility provider in the vault installed the new raceways during normal business hours. The switch over from the original wiring system to the new system was performed overnight on a weekend, allowing the building electrical system to be shut down without disrupting normal business operations. Upon connecting the building back to the electric grid, a 96% magnetic field reduction was achieved and the computer interference was eliminated.