There are certain power transformers whose windings are totally encapsulated by epoxy resin so that it becomes easier to install them.
These types of transformers are called dry type transformers which is also called cast resin transformer.
These transformers are quite safe and protected against fire. These types of transformers can be used in wide variety of applications which can be installed both indoors and outdoors.
The purpose of transformers is for increasing or decreasing voltage and currents within electrical circuits. There are few liquid-type transformers too, but there are number of good reasons why these dry transformers are often recommended.
The applications of these transformers are for utility, industrial and commercial uses.
What use dry-type transformers?
Dry-type transformers usually have no moving parts, which is a static component uses environmentally friendly system with temperature insulation.
Other traditional transformers which are liquid-type transformers can usually work with environmentally taxing materials such as oil or any fire-resistant liquid dielectric.
Dry-type transformers like liquid transformers will not need any fire proof vaults and also need not worry about spreading of toxic gases coming out.
As these dry-type transformers are comparatively much safe, hence they can always be placed indoors or closer to loads, and the system becomes more efficient.
Dry transformers types
Based on the environment or the applications, you may develop slightly different kinds of such transformers. As an example, VPI dry-type transformers will be suitable, if you are looking for radiance protection or advanced mechanical power.
For harsher environment cast coil transformer will be more suitable.
Open wound transformer
These types of transformers are named because of its manufacturing process, where “dip-and-bake” type of method is used. The coils are first heated, then it is dipped in a high-temp varnish. After that it is baked.
Vacuum pressure impregnated
Use of such VPI transformers is mostly industrial and commercial purposes. High-temperature insulation are used which ranks as fluid classification for ‘O’ and ‘K’ type.
These transformers are usually made from materials which can withstand very high temperatures and also sealant that are moisture-resistant polyester, which is typically applied by using a special technique called vacuum pressure impregnation.
Vacuum pressure encapsulated
These transformers can be compared with the above VPI type of transformer. Here instead of using polyester, silicon-based resin is used which creates thicker coating which is highly moisture resistant and also to salt and humidity, thus making it excellent option for harsher environment.