IEEE C62.48

Abstract

This guide applies to surge-protective devices (SSPDs) manufactured to be connected to 50 Hz or 60 z ac power circuits rated at 100&#8211;1000 V rms.<br>This guide describes the effects on SPDs of power system disturbances occurring in these low-voltage ac power circuits. The disturbances are not limited to surges. The effects of the presence and operation of SPDs on he quality of power available to the connected loads are described. The interaction among multiple SPDs on he same circuit is also described.<br>This guide discusses both voltage and current surges. The current surges discussed in this guide are the result of voltage surges. Current surges that are solely the result of load changes and do not result in voltage increases, such s a short circuit, are not discussed in this guide. <br>An SPD &#8217;s primary purpose is to provide surge protection. Devices discussed in this guide contain at least one nonlinear component or diverting surge current and/or dissipating surge energy, such as a metal oxide varistor (MOV), silicon avalanche diode (SAD), thyristor, or spark gap. Uninterruptible power supplies (UPSs), ferroresonators, motor-generators, and filters containing only inductive and/or capacitive components are not onsidered SPDs in this guide.