Insulated Windings

The windings are made of paper insulated conductors of high conductivity soft drawn electrolytic copper conforming to latest standards. The Transformers windings are suitably designed to meet the mechanical, thermal and electrical requirements. The windings are wound with adequate bracing and anchoring tapes in order to achieve a strong self-supporting structure. The major and minor insulation of winding is suitably designed to withstand impulse test levels corresponding to voltage class as specified in the Indian Standard. Adequate cooling ducts are provided between layers and turns to ensure that temperature gradient between winding, oil and hot spot temperature is within permissible limits. This ensures that the rate of insulation ageing is minimum and consequently life expectancy increased. L.V. Windings with round conductors are of multilayer crossover type. Interlayer paper insulation and anchoring tapes are provided to give adequate electrical strength to the coils. H.V. Windings with strip conductors are of disc type (Continuous). Radial ducts are provided between the adjacent discs which serve the dual purpose of providing insulation as well as oil circulation. Core Coil Assembly - Coils are assembled on core limbs after removing top yoke laminations. Trapping and phase connections are made with multi layer paper covered conductors. They are suitably supported and separated to ensure that adequate clearance is maintained.