Core Coil Assembly is done in two methods according to shape of the core. In stack core construction, core is kept steady in vertical direction and coils are lowered form the top.
Core & Coil assembly for distribution / power transformersuser’s special insulating materials like crepe paper tubes & multi paper covered conductors for Oil – Filled and are very strong and robust in construction to withstand short – circuit forces. They are adequately clamped with the tank so that no movement is possible within the tank because of transport jerks or short –circuit forces. After CCA is ready then HV/LV routing is done in accordance with the required Vector Group and type of Bushing/Cable termination.
Oil-Filled –The Core and coil assembly is derived in an oven at a temperature of 90° – 120° C, to improve insulation resistance and remove ingress of moisture in the insulation materials. The dried core coil assembly is boxed up in a pre-fabricated MS tank , and vacuum process is applied for filling oil in the transformers tanks .Oil-Filled in transformers will be PCB free Mineral oil/ Model 7131 / Silicon’s oil /Ester oil / Nynas Nytro etc . As per customer’s requirements.Next