Electrical insulators for high voltage overhead line
Different housings are available these days for the external insulation of EHV and UHV bushings. These include: porcelain, which may or may not also be coated with RTV silicone material to improve pollution performance; hybrid housings consisting of a porcelain core with a polymeric housing; and a composite housing based on an internal FRP tube […]
Porcelain post insulators are widely used on electrical power substation and transmission line systems. In the substation line system, post insulators are commonly seen as station post insulators. On both sides of the station post insulator, there are flanges with drilled holes for bolts fixing. These station post insulators are fixed on the bottom base […]
What is a composite insulator? The composite insulator is also called the polymeric insulator. It is developed after toughened glass insulator and ceramic insulators, whose main insulation structure is consists of a fiberglass core (rod) and silicon housing and sheds. One both sides, 2 metallic fittings are installed on each side with crimping technics. These […]
Scope and object This International Standard applies to composite suspension/tension insulators consisting of a load-bearing cylindrical insulating solid core consisting of fibers – usually glass – in a resin-based matrix, a housing (outside the insulating core) made of polymeric material and end fittings permanently attached to the insulating core. Composite insulators covered by this standard […]
Composite insulator’s shed and sheath are be made of high temperature vulcanizing (HTV) type silicone rubber, having silicone polymer content by weight 30% minimum. Alumina Trihydrate (ATH) is used as a filler. The filler is properly mixed with silicone compounds to ensure uniform distribution. The thickness of the sheath shall be a minimum of 3 […]
The creation of composite insulator started before the 1960s. This new insulator was firstly applied in America and then in France and Germany soon afterwards. It was quite slow for user to accept insulator with silicone rubber material in the beginning as most technical innovation would have some key problems to solve in the history. […]
Composite insulators consist of an insulating core, bearing the mechanical load protected by a polymeric housing, the load being transmitted to the core by end fittings. Despite these common features, the materials used and the construction details employed by different manufacturers may be quite different. Some tests have been grouped together as “Design tests”, to be performed only […]
Last time we talked about sample test of silicone composite insulator for AC system above 1KV, the IEC 61109:2008 has defined it clearly. Today let’s the coming section”routine test” of polymeric insulator in this IEC 61109: 13 Routine tests 13.1 Mechanical routine test Every insulator shall withstand, at ambient temperature, a tensile load at RTL […]
Sample test is a major method of insulator acceptance inspection for mass production. It is widely used by inspectors of insulators from manufacturers, power girds and electrical laboratories. Here we have definition, rules, test method and acceptance criteria of composite insulator of suspension type and tension type of international standard IEC 61109:2008 “spension and tension […]
Damage limit proof test and test of the tightness of the interface between end fittings and insulator housing,these two tests are two of the most important test in inspection process of composite insulator. Here is how international standard IEC 61109:2008 “Suspension and tension insulators for AC system with a nominal voltage greater than 1000V” defines these 2 […]