Esperience from Insulators with RTV Silicone Rubber Sheds and Shed Coatings
(1989)Abstract
long-rod c:anp::>site insulators, with
weather sheds rrade of room temperature vulcanizing
silicon rubber CXXTCX)UOds (RIV), ..ere exposed for m3.rly
years to HVAC and HVIX: under realistic O'.)nditions and
natural p::>llution. It 1110s found that tfle shed material,
quite in contrary to the experience gained
fran insulators with~sheds of other organic rraterials
e g EP!l'1 rubber, undergoes a slo..1 degradation which
improves the already superior water repelling properties
of the silicon rubber CXXTCX)unds. The improvenEnt
seems to be due to a low molecular layer which
is produced on the surface of the insulator sheds.
This layer improves the hydrophobicity of the surface,
while protecting the surface fran further de-
Aaation. Weather sheds of p::>rcelain housings O'.)ated
Wh a thin layer of R'.lV give similar results to
those obtained with long-rod silicon rubber insulators.
The RIV O'.)ating, although it led to increased
salt dep::>sit density, reduces the leak currents and
the withstand of the insulator under the sane p::>llution
conditions.
