Oil-cooled Current Transformer

Description: Oil cooled current transformer is for outdoor installation providing reliable measurement of power and protection of distribution system up to 66 kV rating. The reliability of the current transformer is very crucial and of prime importance in modern switchgear. The unit is hermetically sealed. The primary rating is available up to 1200 A. Multi-ratio transformation can be provided by tapping on secondary winding. Maximum five secondary windings can be provided to meet the requirements of metering, protection and special purpose protective class. The CTs are also provided with nitrogen gas filled on the top of the oil. Higher insulation level is custom built. Salient features are oil/paper insulation, high insulation reliability, metal parts treated for corrosion resistance, use of porcelain bushing suitable for heavily polluted atmosphere, easy accessibility to LV terminals, testing for lightning impulse voltage test, short-time thermal and dynamic current test and temperature rise test. Provision is made for optional accessories like hot dip galvanised ferrous parts exposed to atmosphere, primary terminal connectors, cable glands, stainless steel bellows, nitrogen gas filling above oil level, and arcing horns. The complete assembly can be easily transported using the lifting hooks provided on the tank. Technical specifications: ratio - up to 1200 A; accuracy class - as required; burden - as required; short time current rating and its duration - up to 31.5 kA/3 sec; basic insulation level - 72.5/140/350 kV; creepage distance - 25 mm/kV, that is,1810 mm (min); and number of secondary cores - 5 (max).