Some Considerations for New and Retrofil Applications of Natural Ester Dielectric Fluids in Medium and Large Power Transformers

Waukesha Electric Systems has been actively involved in exploring and developing the application of natural ester dielectric fluid in medium and large power transformers in both new and retrofill applications. Initial applications of this material have primarily been to take advantage of the fire safety properties it offers. Many of the initial retrofills have been in power generating plants. Environmental biodegradability has been the second major reason for use of this material. Application consideration for use with de-energized tap changers, load tap changers and forced oil pumps are discussed. Application considerations of higher viscosity, higher oil temperature rise and transformer ratings are discussed. Application in mobile transformers is discussed