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.<\/p>\n
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:<\/p>\n
switching impulse spark-over voltage;<\/p>\n<\/li>\n
residual voltage at steep current and switching current impulse;<\/p>\n<\/li>\n
thermal stability;<\/p>\n<\/li>\n
long-duration current impulse withstand duty;<\/p>\n<\/li>\n
power-frequency voltage versus time characteristics of an arrester;<\/p>\n<\/li>\n
disconnector test;<\/p>\n<\/li>\n
aging duties by power-frequency voltage.<\/p>\n<\/li>\n<\/ul>\n
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.<\/p>\n
Designs with the EGLA’s external series gap installed in parallel to an insulator are not covered by this document.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | National foreword <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | INTRODUCTION Figures Figure 1 \u2013 Configuration of an EGLA with insulator and arcing horn <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4 Identification and classification 4.1 EGLA identification 4.2 EGLA classification Tables Table 1 \u2013 EGLA classification \u2013 \u201cSeries X\u201d and \u201cSeries Y\u201c <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5 Standard ratings and service conditions 5.1 Standard rated voltages 5.2 Standard rated frequencies 5.3 Standard nominal discharge currents 5.4 Service conditions 5.4.1 Normal service conditions 5.4.2 Special service conditions Table 2 \u2013 Steps of rated voltages (r.m.s. values) <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 6 Requirements 6.1 Insulation withstand of the SVU and the complete EGLA 6.1.1 Insulation withstand of the housing of the SVU 6.1.2 Insulation withstand of EGLA with shorted (failed) SVU 6.2 Residual voltages 6.3 High current duty 6.4 Lightning discharge capability 6.5 Short-circuit performance of the SVU <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 6.6 Mechanical performance 6.7 Weather aging of SVU 6.8 Reference voltage of the SVU 6.9 Internal partial discharges 6.10 Coordination between insulator withstand and EGLA protective level <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 6.11 Follow current interrupting 6.12 Electromagnetic compatibility 6.13 End of life 7 General testing procedure 7.1 Measuring equipment and uncertainty 7.2 Test samples <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 8 Type tests 8.1 General 8.2 Insulation withstand tests on the SVU housing and on the EGLA with failed SVU 8.2.1 General Table 3 \u2013 Type tests (all tests to be performed with or without insulator assembly; by manufacturer’s decision) <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 8.2.2 Insulation withstand test on the SVU housing 8.2.3 Insulation withstand tests on EGLA with failed SVU <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 8.3 Residual voltage tests 8.3.1 General 8.3.2 Procedure for correction and calculation of inductive voltages <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 8.3.3 Lightning current impulse residual voltage test <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 8.3.4 High current impulse residual voltage test 8.4 Standard lightning impulse sparkover test <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 8.5 High current impulse withstand test 8.5.1 Selection of test samples 8.5.2 Test procedure <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 8.5.3 Test evaluation 8.6 Test to verify the repetitive charge transfer rating, Qrs with lightning discharges 8.6.1 MO resistors <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure 2 \u2013 Test procedure to verify the repetitive charge transfer rating, Qrs <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 8.6.2 Series gap <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 8.7 Short-circuit tests 8.7.1 General Figure 3 \u2013 Test procedure to verify the repetitive charge withstand of the series gap <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 8.7.2 Preparation of the test samples <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 8.7.3 Mounting of the test sample <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 8.7.4 High-current short-circuit tests <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 8.7.5 Low-current short-circuit test 8.7.6 Evaluation of test results <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Table 4 \u2013 Test requirements <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Table 5 \u2013 Required currents for short-circuit tests <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Figure 4 \u2013 Examples of SVU units <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure 5 \u2013 Short-circuit test setup <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 8.8 Follow current interrupting test 8.8.1 General 8.8.2 "Test method A" Figure 6 \u2013 Example of a test circuit for re-applying pre-failing circuit immediately before applying the short-circuit test current <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 8.8.3 "Test method B" <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 8.9 Mechanical load tests on the SVU 8.9.1 General 8.9.2 Bending test <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Figure 7 \u2013 Thermo-mechanical test <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | Figure 8 \u2013 Example of the test arrangement for the thermo-mechanical test and direction of the cantilever load <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | Figure 9 \u2013 Test sequence of the water immersion test <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 8.9.3 Vibration test <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | 8.10 Weather aging tests 8.10.1 General 8.10.2 Sample preparation 8.10.3 Test procedure 8.10.4 Test evaluation <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 8.10.5 Additional test procedure for polymer (composite and cast resin) housed SVUs 8.11 Radio interference voltage (RIV) test 9 Routine tests 9.1 General <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | 10 Acceptance tests 10.1 General 10.2 Reference voltage measurement of SVU Table 6 \u2013 Acceptance tests <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 10.3 Internal partial discharge test of SVU 10.4 Radio interference voltage (RIV) test 10.5 Test for coordination between insulator withstand and EGLA protective level 10.5.1 General 10.5.2 Steep front impulse test Table 7 \u2013 Virtual steepness of wave front of steep front impulses <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | 10.5.3 Standard lightning impulse sparkover test 10.6 Follow current interrupting test 10.6.1 General <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | 10.6.2 Test procedure 10.6.3 Test sequence 10.6.4 Test evaluation 10.7 Vibration test on the SVU with attached electrode 10.7.1 General 10.7.2 Sample preparation 10.7.3 Test procedure and test condition <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | 10.7.4 Test evaluation <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Annex A (informative) Example of a test circuit for the follow current interrupting test Figure A.1 \u2013 Example of a test circuit for the follow current interrupting test <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | Annex B (normative) Mechanical considerations B.1 Test of bending moment Figure B.1 \u2013 Bending moment \u2013 Multi-unit SVU <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | B.2 Definition of mechanical loads Figure B.2 \u2013 Definition of mechanical loads <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | B.3 Definition of seal leak rate Figure B.3 \u2013 SVU unit <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | B.4 Calculation of wind-bending-moment Figure B.4 \u2013 SVU dimensions <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | B.5 Flow chart \u2013 Procedures of tests of bending moment for porcelain\/cast resin and polymer-housed SVUs Figure B.5 \u2013 Procedures of tests of bending moment for porcelain\/cast resin and polymer-housed SVUs <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Annex C (normative) Special service conditions C.1 General C.2 Temperature in excess of +40 \u00b0C or below \u201340 \u00b0C C.3 Application at altitudes higher than 1 000\u00a0m C.4 Fumes or vapours that may cause deterioration of insulating surface or mounting hardware C.5 Excessive contamination by smoke, dirt, salt spray or other conducting materials C.6 Excessive exposure to moisture, humidity, dripping water, or steam C.7 Live washing of arrester C.8 Unusual transportation or storage <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | C.9 Non-vertical erection and suspended erection C.10 Wind speed > 34 m\/s C.11 Earthquake C.12 Torsional loading of the arrester <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Surge arresters – Metal-oxide surge arresters with external series gap (EGLA) for overhead transmission and distribution lines of a.c. systems above 1 kV<\/b><\/p>\n |