Classification And Characteristics Of Insulating Sleevings

    Insulation Casing Classification: Insulation casing According to the use of power plants and electrical class. The former is mainly through the wall casing, the latter has transformer casing, capacitor casing and circuit breaker casing. According to the insulating structure, it is divided into single insulating casing, composite insulating casing and capacitance type casing.Insulating Sleevings

    A single insulating casing is insulated with pure porcelain or resin and is often made into a wall casing for 35,000 volts and below voltage levels. Its insulating parts are tubular, central card or rubber flange to be fixed on the perforated wall. Generally, the flange is gray cast iron, when the working current is greater than 1500, the insulating casing is often non-magnetic to reduce heat. The insulating structure of single insulated casing is divided into two types: air cavity and air cavity short circuit. The air chamber casing is used for 10,000 volts and the following voltage grades, and the air chamber between the conductor and the porcelain sleeve is an auxiliary insulation, which can reduce the casing capacitance and increase the corona voltage and the sliding lightning pressure of the casing.Insulating Sleevings

    When the voltage level is higher ($number kv), the cavity inside the air chamber will be corona and the above effect is ineffective, then the air cavity short circuit structure is adopted. The inner wall of the porcelain sleeve is coated with a semiconductor glaze, and a spring sheet and a conductor are connected to make the air cavity short-circuit to eliminate the corona. Corona and slippage may still occur near the flange. Usually a large umbrella skirt is arranged on the surface of the porcelain sleeve near the flange, and a half conductive layer is applied near the flange to distribute the electric field evenly and to improve the discharge characteristic of the casing.Insulating Sleevings

    Composite insulating casing, used as insulating medium for oil or gas, is usually made into a transformer casing or circuit breaker casing, which is usually rated at 35,000 volts below. The inner cavity of the composite insulated casing conductor and the porcelain suite is filled with transformer oil and plays a radial insulating role. When the voltage exceeds 35,000 volts, the conductor is sheathed with an insulating tube or a package cable to enhance insulation. The conductor structure of composite insulated casing has two kinds of cable-type and guide-Rod. The cable-type use of the transformer's lead cables directly through the casing, easy installation.Insulating Sleevings

   When the working current is greater than 600, the cable-type structure is difficult to install, generally using the guide bar structure. The capacitive casing is composed of a capacitor core, a porcelain sleeve, a metal accessory and a conductor. Mainly used in EHV transformers and circuit breakers. Its upper part is in the atmosphere, the lower part works in the fuel tank. capacitor-type casing capacitor heart as an internal insulation, porcelain sleeve as an external insulation, also play a role in protecting the capacitance of the heart. The electric field of the porcelain sleeve surface is evenly distributed by the pressure of the inner capacitance heart, which improves the electrical insulation performance of the casing. The metal accessory has intermediate connection sleeve (flange), end cover, equal pressure ball and so on. The conductor is a cable or a rigid steel pipe.Insulating Sleevings