Porcelain Station Post Insulators FAQ
• Can you use Station Post Insulators horizontally?
• If an insulator has bare spots on it, is it still functional?
• Do we need to urgently replace a unit if the petticoat is chipped or broken?
• What insulators does Lapp Insulators LLC provide for contaminated insulator applications?
• What are RG® Insulators and how do they work?
• Does Lapp Insulators LLC offer designs not found in Catalog 10C for Station Post Insulators?
Can you use Station Post Insulators horizontally?
Yes, station post insulators can be used horizontally. However, when designing for horizontal application the working load strength must be de-rated for 50% of the net weight of the unit. In other words, if you have a station post rated at 2,500 lbs. cantilever, the maximum recommended working load is 1,000 lbs. (40% of rating). If the net unit weight is 400 lbs., 50% of the net weight is 200 lbs, then the maximum recommended working load for a unit in a horizontal application then becomes 800 lbs. in cantilever rating.
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If an insulator has bare spots on it, is it still functional?
Some porcelain may display bare spots or an occasional chip or broken petticoat. Some bare spots may be a result from imperfection during manufacturing which is allowable to some degree according to the manufacturer’s specifications or industry standards. Small bare spots are allowable but only on the petticoat surface, not the core or strength member of the unit.
Glaze serves the purpose of self cleaning and strength for the insulator. However, small bare spots on the petticoat surface do not impact the strength or the mechanical and electrical performance of the insulator. In addition, Porcelain is not a porous material and will not absorb moisture if not fully covered by glaze.
Small bare spots as a result of non-uniform glaze covering may be touched up using non-conductive enamel paint.
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Do we need to urgently replace a unit if the petticoat is chipped or broken?
On occasion, insulators are broken or damaged in service. If a station post insulator has a broken or chipped petticoat it may continue to function without any issues as long as the fracture is not impeding the core or mechanical strength member of the insulator. In addition, please note that porcelain is a ceramic material and is very sharp when broken and could be dangerous to handle. We suggest that broken insulators be marked or identified as a caution or taken out of service at the earliest convenience.
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What insulators does Lapp Insulators LLC provide for contaminated insulator applications?
Lapp provides a wide range of options for insulators in applications for high contaminated areas.
- Over Insulation - Some users may choose the option to increase the BIL to achieve a greater dry arcing distance and increase the leakage just by increasing the height of the insulator.
- High Leakage and Extra High Leakage insulators – Lapp offers several different leakage options from standard leakage to extra high leakage which is a proven industry wide solution to heavy contamination areas.
- RG® Insulators – Lapp also offers a semi-conductive Insulator that is ideal for high contamination applications. RG® Insulators are manufactured using a special proprietary glaze that is backed by the longest field experience in the industry of more than 40 years.
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What are RG® Insulators and how do they work?
RG® Insulators employ a unique semi-conductive glaze which inhibits arcing and flashovers due to contamination. The glaze is a permanent integral part of the insulator. Their performance is derived from three factors
- Linear Voltage Distribution occurs across the entire length of the insulator creating a uniform stress that is even across the entire unit.
- Heating effect of only a few degrees above the ambient temperature is a result of 1 milliamp of current flow across the surface of the insulator. This discourages moisture accumulation which makes contamination conductive.
- Prevention of dry band arcing due to the combination of contamination and moisture
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What are the benefits of RG® glaze?
RG® Insulators can significantly reduce construction and operating costs. They eliminate the need for washing. They reduce EMI problems associated with standard insulators. They eliminate the need for coatings or greasing in contaminated areas.
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Does Lapp Insulators LLC offer designs not found in Catalog 10C for Station Post Insulators?
Lapp offers a variety of special designs for specific customer applications. This includes both electrical and mechanical characteristics of the insulator. Those applications include high or extra high strength applications, high or extra high leakage applications, underhung or diagonal applications, and seismic applications.
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