IEEE C62.31

Abstract

This standard applies to gas-tube surge-protective device components for application on systems with voltages less than or equal to 1000 V rms or 1200 V dc. These protective devices are designed to limit voltage surges on balanced or unbalanced communication circuits and on power circuits operating from direct current (dc) to 420 Hz. This standard contains a series of standard test criteria for determining the electrical characteristics of gas-tube surge-protective devices.<br>The tests in this standard are intended as design tests as defined in <em>The Authoritative Dictionary of IEEE Standard Terms</em> [B1]¹ and provide a means of comparison among various gas-tube surge-protective device components.²<br>Gas-tube devices are used to provide over-voltage protection in electrical circuits. When the breakdown voltage of the gas tube is exceeded, the normal high-impedance state of the tube changes to a lowimpedance state to allow the gas tube to conduct the surge discharge current. After the tube conducts the surge discharge current, it interrupts the flow of power follow current and returns to its high-impedance state.<br>This standard&#8217;s test criteria and definitions provide a common engineering language that is beneficial to the user and manufacturer of gas-tube surge-protective devices.<br>¹The numbers in brackets correspond to those of the bibliography in Annex A. <br>²In this standard, the term <em>gas tube</em> or <em>gas-tube surge-protective device component</em> is used when the definition of gas-tube surge arrester (see Clause 2) is intended, and the term <em>protector</em> is used when the definition of surge protector (see Clause 2) is intended. When a test applies to both protectors and surge-protective device components, the term <em>device</em> or <em>gas-tube device</em> is used alone. For the purpose of this standard, all connections to a device are by means of the terminals.