Insomnia and High End Capacitors

[GM]

IME the oil is a processed canola oil with additives.

FWIW, the motor run, power factor correction caps the plant bought were filled with castor oil after PCBs were outlawed, though do recall some foreign brands spec'd. canola or mineral oil.

edit: this patent might be useful for spec'ing high end audio caps if not already in use: http://www.google.com/patents/US8741187
GM

 

[eriksquires]

Canola oil? Well, that's weird. I mean, Canola oil IS highly processed from Rapeseed oil. Wonder why they didn't just use that directly, save a processing step. I learned something new. I wonder if a cap blows if it smells like french fries?

Best,

Erik

 

[freddi]

those TemCo seem to measure pretty good - a 40uF motor run cap =39.67uF with 0.02ohm ESR on my cheap meter - its heavy but don't oil sloshing around

 

[Max Headroom]

FWIW, the motor run, power factor correction caps the plant bought were filled with castor oil after PCBs were outlawed, though do recall some foreign brands spec'd. canola or mineral oil.

edit: this patent might be useful for spec'ing high end audio caps if not already in use: Patent US8741187 - Vegetable oil of high dielectric purity, method for obtaining same and use ... - Google Patents
GM

CONCLUSION
Nowadays, it is increasingly important that dielectric fluids provide a better balance between high functional performances versus low environmental impacts. Inside transformers, a stable, chemically inert fluid having good thermal and dielectric properties is needed. Outside (for instance in the event of release), the fluid should become environmentally benign by being non-toxic and readily biodegradable.
In this frame, the agricultural commodity oils, used mainly in food products, are not only widely available, but, unlike mineral oil, are derived from renewable resources. They are biodegradable and do not contribute significantly to the net greenhouse gases released to the atmosphere.
The inherent environmental performance, fire safety and chemical and electrical properties of natural vegetable oil and ester based dielectric coolants are advantageous. The insulating and coolant liquid presented in this paper, specifically formulated from conventional crop plants products for use in tank sealed distribution transformers, offers an interesting alternative to mineral oil-filled transformers, but also to dry and non-flammable liquid-filled types used in specialty applications.

VEGETABLE OILS AS SUBSTITUTE FOR MINERAL INSULATING OILS
No mention of additives.

Dan.