Natural Ester Transformer Fluids: Safety, Reliability & Environmental Performance

Fire safety, firewalls, deluge systems, and fluid containment are some of the fire protection problems users face when installing mineral oil filled transformers. Aging substation infrastructure, environmental protection, and resource sustainability are other growing issues. To address these concerns, natural ester fluids are being utilized for their superior fire, environmental, and life extension properties. Natural ester fluid offers the highest fire-point of any insulating fluid at 360degC, and a flawless fire safety record through 10 years and more than 45,000 installations. Natural ester fluid is manufactured from seed oil and biodegradable additives, making it readily biodegradable in the case of a spill. The combination of fire safety and biodegradability typically eliminates the traditional need for firewalls; deluge systems; and can reduce spill containment, reporting, and/or remediation requirements. Properties unique to certain seed oils help to slow the insulation aging rate and to stabilize the electrical performance of the transformer. This paper presents two refinery case studies for natural ester fluids; the first study is for new distribution transformers and the second is for retro-filling existing power transformers.