Cast Coil Transformers: An Alternative to Conventional Dry Type Transformers

Now that askarel insulated transformers are no longer available because of environmental regulations, engineers are looking to new approaches in design of nonflammable transformers. Cast coil construction is one promising new design. Cast coil construction is compared with the more familiar conventional dry type construction with particular attention to 15 kV class units up to 5000 kVA in rating. Questions of reliability, energy efficiency, performance characteristics, maintenance requirements, and initial costs are explored in detail.