ITU-T Recommendations

This Recommendation seeks to establish fundamental testing methods and criteria for the resistibility of telecommunications equipment connected to local subscribers' lines to overvoltages and overcurrents.This Recommendation describes tests that should be applied to equipment which is metallically connected directly to balanced pairs.This Recommendation concentrates on a series of tests made principally at the telecommunication line and mains input terminals.Aspects of overvoltages or overcurrents covered by this Recommendation include surges due to lightning on or near the line plant, short-term induction of alternating voltages from adjacent power lines or railway systems, direct contacts between telecommunication lines and power lines and electrostatic discharges.