Silicone rubber encapsulant for dry-type transformers

New resilient silicone elastomers are now available which appear to meet the electrical performance requirements for underground residential distribution transformers, whether buried or house mounted. Size, safety, weight and efficiency dictate that single residence transformers for underground distribution systems be of the dry-type. Rigid encapsulants presently being evaluated have limitations. This paper describes a new impregnating and potting material which permits compact transformer design, efficient operation, and long life.