Checklist for Insulation Tests
Page 19
4.3
Special Tests
4.3.1 Subsequent Testing of Contact Surfaces, Slide Valves, etc.
Spirals or round brushes cannot be used to test contact surfaces of supporting
belts, supports, branches, slide valves, etc. A separate test with flat brush
electrodes is necessary here.
4.3.2 Correct Testing of Socket Pipes
The insulation of the insertion end of pipes for socket connections applied at
the factory mean that there is no conductive connection between the two
pipes. The last pipe laid can be easily earthed with the earthing cable of the
tester, but not the last pipe but one. This is of significance particularly during
the examination of the subsequent socket insulation. In such cases, capaci-
tive earthing can be expediently employed (see section 3.1.3).
