Electrical corona resistance

The most important electrical properties of insulation are dielectric strength, insulation resistance, dielectric constant, and power factor. Corona resistance, although not stricdy an electrical property, is usually considered also (10). 

Corona resistance -of insulating matenal [INSULATION, ELECTRIC] (Vol 14)... 

The basic role of gas in the electric properties of plastic foams postulated by Domkin has been confirmed by Giessner in a study on the electric properties of epoxide foams, the cells of which were filled with a electronegative gas, sulfur hexafluoride (SFg). The introduction of SFg results in very good dielectric properties over a wide temperature interval, including high Ebr corona resistance (Fig. 21). Previously, Palmer established that Ebr in the case of SFg is by 3.5 times higher than for air. 

Aircraft Electrical Potting Compound - Low temperature flexibility, resistance to corona, resistance to hydraulic fluids and aircraft fuels. 

Electrical properties (insulating, dielectric breakdown, corona resistance, and so on) of ethylene-propylene rubbers are excellent. This is especially true for peroxide-cured EPR. 

Corona resistance Among the factors contributing to the breakdown of insulating materials is dielectric heating at high frequencies and, in many instances, the effect of corona. Corona is usually described as the partial breakdown of insulation due to the concentration of electrical stress at sharp edges, or actual breakdown of insulation when placed in series with another insulation having a different dielectric constant. 

PCTFE exhibits very good electrical properties ia terms of high iasulation resistance, minimal trackiag, corona formation, and surface flashover due to the polymer s nonwettable surface and ultralow moisture absorption (Table 3). 

We can define the principal electrical properties of polymers in terms of four characteristics electrical resistance, capacitive properties, dielectric strength, and arc resistance. We can change the surface characteristics of a polymer by subjecting it to a corona discharge generated by a strong electrical field. Lastly, we must also consider the influence of other physical properties on the application of polymers in electrical applications. 

The polymer requires compounding with normal fillers to produce useful compounds. Chlorosulfonated polyethylene (CSM) excels in resistance to attack by oxygen, ozone, corrosive chemicals, and oil, and in addition has very good electrical properties. Electrical stability and resistance to corona and arc are good. The physical properties and abrasion resistance are also good. Light-colored goods made from CSM have excellent color-fastness. Due to the presence of chlorine atoms, this elastomer shows excellent flame resistance. 

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