Resin cast transformers are made of epoxy resin and quartz powder mixture which makes them resistant to fire. These transformers use air instead of oil to col down and hence entail lower maintenance costs, and tend to be environmentally friendly. Resin cast transformers are also able to withstand short time overloads better than oil-based transformers as they have a resin encapsulated winding. Lastly, Smooth coil surface inside the resin cast transformers prevents the buildup of dust inside the transformer
