User´s experiences with cast coil transformers

This paper reviews the cast coil transformer operating experiences of a large forest products company. The excellent operating record of more than 230 transformers is strong testimony for cast coil insulation systems and for the rating specification used. The temperature versus loading curves that were developed have been very helpful in providing user plant personnel with understanding and acceptance of cast coil transformers. Thanks to some unusual short-term overloading conditions, data were gathered to provide thermal time constant curves.