For an uninterrupted power supply, many firms install transformers. Among the other types of transformers, the dry type transformer also known as the cast resin transformer is widely accepted for the hassle-free usage and low-maintenance it demands. These transformers, unlike the liquid-filled requiring oils and other liquids for cooling, depend solely on the insulation systems of high temperature that are completely safe for the environment.
At places like the hospitals, schools, chemical plants, factories, etc where the safety is the greatest concern, the management prefers to install the dry-type transformers for the safety quotient they guarantee.
The static transformers don’t demand any high-maintenance rather the transformers ensure trouble-free usage and longevity. But it must be installed in a place where it gets sufficient space for ventilation.
As the windings are exposed, the dry-type transformers are prone to get affected by the dirt, dust, moisture, etc causing corrosion. With proper preventive measures as suggested by experts, the issue can get resolved by preventing dust invasion and periodical cleaning of the transformers.
Here, explore the different types of dry-type or cast resin transformers—
VPI or Vacuum Pressure Impregnated Transformer
Mainly for industrial and commercial purposes, the VPI transformers are used. These are specially designed and built transformers where the heat resisting materials are used. It’s mandatory to use materials that can resist the high temperature of more than 30 MVA. Moisture resisting polyester sealants are also used for the impregnation technique of the vacuum pressure. The high-temperature insulation of the VPIs ranks in between and sometimes over O and K classifications fluids.
Open Wound Transformer
The name of the transformer sounds ironic yet it’s been so named considering the manufacturing process. It’s the “dip and bake” method that involves creating the transformers. It’s the process where the coils are heated, then dipped in the varnish of high-temperature after which it gets baked. This whole process which is followed for making the transformer is known as an open would method.
VPE or Vacuum Pressure Encapsulated
The VPE is comparable with the VPI. Instead of using the polyester, silicon-based resin is mainly used for building these transformers as it provides a thicker coating capable of withstanding salt, humidity, and moisture. For harsher environments that are susceptible to alkalis, chlorides, acids, etc. using these transformers is an excellent choice.
Cast Coil Transformers
Strongly recommended for extreme weathers that demands minimum upkeep. Ideally, these are installed inside nuclear plants, mines, production plants, ships, tunnels etc.