An Important Link in Whole-House Protection: Surge Reference Equalizers

The increasing use of electronics in residential applications has been paralleled by a realization that surge protection may be necessary for this type of equipment. Installing a surge-protective device on the power-line port as well as on the communications-line port of an equipment might appear sufficient to ensure this protection. However, the normal operation of one of the protective devices during a surge event can create differences in the voltages of the references of the two ports. This difference in voltages, applied across the equipment or across a communication link between two pieces of equipment, can result in permanent damage as well as upset. Equalizing these voltages can be achieved by proper routing of the two lines through a single device, called Surge Reference Equalizer, and thus avoid the risk of damage.