This technical specification is applicable for the determination of the d.c. withstand characteristics of ceramic and glass insulators to be used outdoors and exposed to polluted atmospheres, on d.c. systems with the highest voltage of the system greater than \u00b1 1 000 V.<\/p>\n
These tests are not applicable to polymeric insulators, to greased insulators or to special types of insulators (e.g. insulators with semiconducting glaze or covered with any organic insulating material).<\/p>\n
The object of this technical specification 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 | ||||||
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | Figures Figure 1 \u2013 Ripple amplitude and actual mean voltage, measured ona resistive load absorbing 100 mA <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4 General test requirements 4.1 General <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.2 Test methods 4.3 Arrangement of insulator for test 4.3.1 Test configuration 4.3.2 Insulator cleaning <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4.4 Requirements for the test circuit 4.4.1 Test voltage 4.4.2 Atmospheric corrections 4.4.3 Characteristics of the measuring systems 4.4.4 Identification of flashover <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5 Salt fog method 5.1 General information 5.2 Salt solution Figure 2 \u2013 Voltage drop and voltage overshoot and leakage current <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Tables Table 1 \u2013 Salt-fog method: correspondence between the valueof salinity and volume conductivity of the solutionat a temperature of 20 \u00b0C <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.3 Spraying system Figure 3 \u2013 Value of factor b versus solution temperature ( <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure 4 \u2013 Typical construction of fog spray nozzle <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 5.4 Conditions before starting the test 5.5 Preconditioning process Figure 5 \u2013 Test layout for inclined insulators <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.6 Withstand test 5.7 Acceptance criteria for the withstand test 6 Solid layer method 6.1 General information <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 6.2 Main characteristics of inert materials 6.3 Composition of the contaminating suspension Table 2 \u2013 Main characteristics of the inert materials used in solid layer suspensions <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 6.4 Application of the pollution layer Table 3 \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 | ||||||
| 25<\/td>\n | 6.5 Determination of the degree of pollution of the test insulator 6.6 Test procedure <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 6.7 Withstand test and acceptance criteria <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Annexes Annex A (informative) Method for checking the uniformity of the layer Figure A.1 \u2013 Arrangement of the probe electrodes <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Figure A.2 \u2013 Circuit diagram of the meter <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Annex B (informative) Determination of the withstand characteristics of insulators B.1 General B.2 Determination of the maximum withstand degree of pollution at a given test voltage B.3 Determination of the maximum withstand voltage at a given degree of pollution <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | B.4 Determination of the 50 % withstand voltage at a given degree of pollution <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Annex C (informative) Additional recommendations concerning the solid layer method procedures C.1 General C.2 Contamination practice C.3 Drying of the pollution layer C.4 Checking the wetting action of the fog <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | C.5 Checking fog uniformity for large or complex test objects C.6 Fog input to the test chamber <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | C.7 Duration of the withstand test C.8 Evaluation of the reference salt deposit density (SDD) Figure C.1 \u2013 Determination of layer conductance and evaluationof its rise time Tc = t2 \u2013 t1 <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Annex D (informative) Information to check equipment for artificial pollution tests <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Table D.1 \u2013 (Provisional) <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Annex E (informative) Supplementary information on artificial pollution tests on insulators for voltage systems of ( 600 kV and above (solid layer method procedure B) E.1 General E.2 Test chamber E.3 Fog generator E.4 Wetting action and uniformity of fog density E.5 Test of very large insulators <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Annex F (informative) Further investigation <\/td>\n<\/tr>\n | ||||||
| 38<\/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 d.c. systems<\/b><\/p>\n |