800 Kva 11kv Cast Resin Dry Type Transformer

The 800 kva 11kv cast resin dry type transformer, which is produced by Wenzhou XiFa electric Power Equipment Co., Ltd, has excellent insulation performance. Both the high voltage and low voltage coils are wound without copper foil oxidation. The layers of the coils are insulated with F class materials and reinforced with glass grid plates on the inside and outside. All the leads are welded by argon arc. It is cast with epoxy resin under high vacuum.

Foil Winding Machine

Winding Workshop

Transformer in Winding

The epoxy resin used has good properties, resisting cracking, withstanding high temperatures, having high mechanical strength and a long service life. The dry type transformer is flame retardant, moisture proof, explosion proof. It has strong short circuit resistance and high lightning impulse resistance. Wenzhou XiFa is capable to produce more than 30 EA of 800 kva dry type distribution transformer within 30 days. Each of casting resin transformer is matched the requirements on BOQ.

Casting Mould

Casting Winding

Finished Product

Technical parameter:

Product Design Feature:

The fundamental reason why 800 kva 11kv cast resin dry type transformer need to be reduced in rated capacity is that the air density in high altitude environments decreases.

Transformer in Assemble

Casting Machine and Oven

Testing Center

Firstly, dry transformers rely on air convection and radiation for heat dissipation. The higher the altitude, the thinner the air becomes and the smaller the convective heat transfer coefficient becomes. The heat generated by the windings and cores cannot be dissipated in time. If they are still operated at full load at the rated capacity, the winding temperature rise will exceed the limit, accelerating insulation aging, shortening the service life, and even triggering overheating faults. Secondly, air is also the insulating medium for the 800 kva 11kv cast resin dry type transformer’s high voltage part. The breakdown field strength of thin air decreases. Under the same voltage, the insulation margin of the electrical gap and creepage distance is insufficient, and local discharge, creepage, and flashover problems are prone to occur.

Transformer Workshop

Substation Workshop

Panel Workshop

Therefore, within 1000 meters: the air parameters are close to the design reference values, and both heat dissipation and insulation meet the design requirements, and no capacity reduction is necessary.

In the 1000 to 2000 meters range: the air density linearly decreases, and the deterioration of heat dissipation and insulation is stable. Therefore, a linear capacity reduction rule is adopted, reducing by 0.5% for every 100 meters increase in altitude.

Above 2000 meters: the air attenuation intensifies, and merely reducing the capacity is no longer sufficient. It is also necessary to increase the electrical gap and strengthen the insulation structure.

Wenzhou XiFa electric Power Equipment Co., Ltd would be promised to produce each 800 kva 11kv cast resin dry type transformer with full capacity rating to ensure terminal users will receive the cast resin dry type transformer exactly same with the describe on the BOQ.