Coil winding is performed in the dust-proof air-conditioned and humidity-controlled room in order to raise the quality of product. The transformer coils are made of electrolytic copper strip conductors with rectangular cross-section and rounded corners which are wrapped with several layers of kraft paper. Several winding methods are employed to meet the requirement of the customers.

Insulations for the transformer are produced and stocked in the air-conditioned
room in order to prevent insulation material from absorbing moisture.

The coil is pressurized while being heated at the proper temperature for 36~48 hours in the coil stabilizing treatment chamber to acquire enough strength to withstand the electromagnetic force under severe short circuit condition.

The high quality silicon steel strips are cut by modern automatic cutting machine into sheets. These sheets are stacked horizontally on the core raising table, each corner being carefully miter-jointed to make the best use of properties of the core material. The stacked core is clamped to the table and is gradually raised to the upright position together with the table to avoid undue mechanical stress in the core, so that high quality of the core can be assured.

The connection between the winding ends and the bushings, as well as between the winding and the tap changer, are made of copper cables insulated by wrapping with Kraft paper. All joints between conductors are tightly well-connected with smooth surface to reduce the electric stress.

Tank parts are carefully welded both inside and outside and are thoroughly checked for oil leakage when the tank is completed. These tanks can withstand a full vacuum and also the proper internal pressure test. Both inside and outside surfaces of tank are shotblasted thoroughly before being coated with the rust proof primer and final painting.

High quality panel type radiators are produced by automatic line consisting of panel welding, molding press, assembling and painting.