Foreword
Cooperating organizations
Methods of test
Section one. General
1. Scope
2. References
3. Definitions
4. Values of voltages
5. Values which characterize a post insulator
6. Marking
Section two. General requirements for tests
7. General requirements for electrical tests
8. Lightning impulse voltage tests
9. Switching impulse voltage tests
10. Power-frequency voltage tests
11. Wet tests
12. Standard atmospheric conditions for tests
13. Correction factors for atmospheric conditions
14. Classification of tests
Section three. Tests in group 1 (type tests)
15. General
16. General requirements for electrical tests in group 1
17. Dry lightning impulse withstand voltage test
18. Dry or wet switching impulse withstand voltage
test
19. Dry power-frequency withstand voltage test
(applicable only to post insulators for indoor use)
20. Wet power-frequency withstand voltage test
(applicable only to post insulators for outdoor use)
21. Tests for mechanical strength
22. Test for deflection under load
Section four. Tests in group II (sample tests)
23. General
24. Verification of dimensions
25. Temperature cycle test
26. Power-frequency puncture test
27. Porosity test (for ceramic post insulators only)
28. Galvanizing test
29. Re-test procedure
Section five. Test in group III (routine tests)
30. General
31. Visual examination
32. Mechanical routine test
33. Thermal shock routine test (for toughened glass
parts only)
34. Electrical routine test (for type B post insulators
and for type B units used for composing a type A
post insulator)
Appendix
A. Methods of testing for tolerances of parallelism,
eccentricity and angular deviation for post
insulators
Figures
1. Temperature correction factor alpha for resistivity
of water as used in wet tests, where p20 and pt
indicate resistivity at 20 deg C and t deg C
2. Corrections for air density. Exponent m versus
insulating distance d in metres
3. Humidity corrections for dry lightning impulse and
dry switching impulse tests Factors k and kh against
humidity
4. Humidity correction for dry power-frequency voltage
test. Factor k against absolute humidity (kh = km
with m given in figure 2)
5. Section through very large insulators indicating the
greatest thickness phi of the insulator
A.1 Untitled
A.2 Untitled
A.3 Untitled