Pour point is defined as the lowest temperature at which a
fluid is observed to flow under specified conditions (ASTM
D97 is a commonly used test method). Conventional
transformer mineral oils have pour points below -40 °C
(-40 °F), lower than pour points of natural ester dielectric
The pour point of Envirotemp FR3 fluid is approximately
-21 °C (-6 °F). However, this pour point temperature
should not be considered a limiting factor when choosing
a dielectric fluid for use in cold environments. For natural
esters like Envirotemp FR3 fluid, cold temperature
performance is not strictly related to flow, but is also a
function of its ability to transfer heat from the coils to the
fluid via thermal conduction and then initiate convection.
I can't speak for this use, but I am sure there would be some additives, to minimize the oil negatives and to oxidize you need oxygen, in many transformers they use nitrogen, no O-2 present.Veg oil oxidizes along with everything it is attempting to protect also.
Ayuh. At the hydros we used to run Envirosyn turbine oil which cost something like $150 a gallon, and was supposed to be environmentally friendly if it leaked. It was too pricey to use in hydraulics, so they used a water-based fluid that worked fine until they didn't do the appropriate maintenance and it dehydrated and thickened. Then I'd suddenly start getting all kinds of calls about hydraulic pumps tripping out on overload.Sometimes in sensitive enviromental areas they require heavy equipment to run friendly oils in the hydraulic systems.