This International Standard is applicable for the determination of the power frequency withstand characteristics of ceramic and glass insulators to be used outdoors and exposed to polluted atmospheres, on a.c. systems with the highest voltage of the system greater than 1 000 V.<\/p>\n
These tests are not directly applicable to polymeric insulators, to greased insulators or to special types of insulators (insulators with semiconducting glaze or covered with any organic insulating material).<\/p>\n
The object of this International Standard is to prescribe procedures for artificial pollution tests applicable to insulators for overhead lines, substations and traction lines and to bushings<\/p>\n
It may also be applied to hollow insulators with suitable precautions to avoid internal flashover. In applying these procedures to apparatus incorporating hollow insulators, the relevant technical committees should consider their effect on any internal equipment and the special precautions which may be necessary.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4 General test requirements 4.1 General 4.2 Test method 4.3 Arrangement of insulator for test 4.3.1 Test configuration <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.3.2 Cleaning of insulator 4.4 Requirements for the testing plant 4.4.1 Test voltage 4.4.2 Atmospheric corrections <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.4.3 Minimum short-circuit current <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5 Salt fog method 5.1 General information 5.2 Salt solution Figures Figure 1 \u2013 Minimum short-circuit current, Isc min, required for the testing plant as a function of the unified specific creepage distance (USCD) of the insulator under test <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | Tables Table 1 \u2013 Salt-fog method: correspondence between the value of salinity, volume conductivity and density of the solution at a temperature of 20 \u00b0C <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 5.3 Spraying system Figure 2 \u2013 Value of factor b as a function of solution temperature <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Figure 3 \u2013 Typical construction of fog spray nozzle <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.4 Conditions before starting the test 5.5 Preconditioning process Figure 4 \u2013 Test layout for inclined insulators <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.6 Withstand test 5.7 Acceptance criterion for the withstand test 6 Solid layer methods 6.1 General information <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 6.2 Main characteristics of inert materials 6.3 Composition of the contaminating suspension 6.3.1 General 6.3.2 Kieselguhr composition Table 2 \u2013 Main characteristics of the inert materials used in solid layer suspensions <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 6.3.3 Kaolin (or Tonoko) composition Table 3 \u2013 Kieselguhr composition: approximate correspondence between the reference degrees of pollution on the insulator and the volume conductivity of the suspension at a temperature of 20 \u00b0C <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 6.4 Application of the pollution layer Table 4 \u2013 Kaolin (or Tonoko) composition: approximate correspondence between the reference degrees of pollution on the insulator and the volume conductivity of the suspension at a temperature of 20 \u00b0C <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6.5 Determination of the degree of pollution of the tested insulator 6.5.1 General 6.5.2 Layer conductivity (K) 6.5.3 Salt deposit density (SDD) <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6.6 General requirements for the wetting of the pollution layer 6.7 Test procedures 6.7.1 General 6.7.2 Procedure A \u2013 Wetting before and during energization <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 6.7.3 Procedure B \u2013 Wetting after energization Figure 5 \u2013 Typical arrangement of steam-fog generator <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 6.8 Withstand test and acceptance criterion (common to both Procedures A and B) <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annexes Annex A (informative) Supplementary information on the assessment of the requirement for the testing plant Table A.1 \u2013 Expected Ih max values related to different USCD values <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Annex B (informative) Determination of the withstand characteristics of insulators B.1 General B.2 Determination of the maximum withstand salinity at a given test voltage B.3 Determination of the maximum withstand voltage, or of the 50 % withstand voltage, at a given reference layer conductivity, or at a given reference salt deposit density B.3.1 Maximum withstand voltage <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | B.3.2 50 % withstand voltage B.4 Withstand values of reference suspension insulators <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Table B.1 \u2013 Ranges of values of withstand characteristics of reference suspension insulators in artificial pollution tests <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Annex C (informative) Measurement of layer conductivity for checking the uniformity of the layer Figure C.1 \u2013 Arrangement of the probe electrodes (all dimensions in mm) <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure C.2 \u2013 Circuit diagram of the meter <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Annex D (informative) Additional recommendations concerning the solid layer method procedures D.1 General D.2 Contamination practice D.3 Drying of the pollution layer D.4 Check of the wetting action of the fog <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | D.5 Checking fog uniformity for large or complex test objects D.6 Fog input in the test chamber D.7 Minimum duration of the withstand test <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | D.8 Evaluation of the reference salt deposit density (SDD) Figure D.1 \u2013 Control of the wetting action of the steam fog: Layer conductance recording during the test on the chosen dummy insulator (standard type of Table B.1) <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Annex E (informative) Supplementary information on artificial pollution tests on insulators for voltage systems of 800 kV and above (solid layer method procedure B) E.1 Introduction E.2 Test chamber E.3 Fog generator E.4 Wetting action and uniformity of fog density <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Artificial pollution tests on high-voltage ceramic and glass insulators to be used on a.c. systems<\/b><\/p>\n |