IEC 60099-8:2017 PDF

Scope: This part of IEC 60099 covers metal-oxide surge arresters with external series gap (externally gapped line arresters (EGLA)) that are applied on overhead transmission and distribution lines@ only to protect insulator assemblies from lightning-caused flashovers. This document defines surge arresters to protect the insulator assembly from lightning-caused over-voltages only. Therefore@ and since metal-oxide resistors are not permanently connected to the line@ the following items are not considered for this document: ? switching impulse spark-over voltage; ? residual voltage at steep current and switching current impulse; ? thermal stability; ? long-duration current impulse withstand duty; ? power-frequency voltage versus time characteristics of an arrester; ? disconnector test; ? aging duties by power-frequency voltage. Considering the particular design concept and the special application on overhead transmission and distribution lines@ some unique requirements and tests are introduced@ such as the verification test for coordination between insulator withstand and EGLA protective level@ the follow current interrupting test@ mechanical load tests@ etc. Designs with the EGLA's external series gap installed in parallel to an insulator are not covered by this document.

IEC 60099-8:2017 history

2017 IEC 60099-8:2018 Surge arresters - Part 8: Metal-oxide surge arresters with external series gap (EGLA) for overhead transmission and distribution lines of a.c. systems above 1 kV
0000 IEC 60099-8:2017 RLV
2011 IEC 60099-8:2011 Surge arresters - Part 8: Metal-oxide surge arresters with external series gap (EGLA) for overhead transmission and distribution lines of a.c. systems above 1 kV