FR-3 oil

FR-3 oil


I've taken fluid samples of FR3 in very cold temperatures before (-30c) and the units had been shut off for 2 hours prior to drawing a sample. The fluid came out as slush. Beyond that experience I can't respond substantively. I know from an environmental standpoint it's better than mineral oil and silicone.


Thanks. Yes although the environmental issue is known, I am confused as to why they are having them retro-filled with fr3, when a "Blast wall" will be separating the 2 units. I have heard of the viscosity difference. Thank you for confirming it. Has anyone run FR3 oil thru a standard filter press? Not that I plan on it, but you never know in the future? Heard it trashes filters quickly.


A blast wall is to just protect one transformer from the other in case of catastrophic failure no? That's what I always thought. Cant comment on the pumping differences. We had it filled by a subcontractor on my last project, they didn't point out any issues or differences.


Many years ago, I was sent to a new wind farm, under construction in Pipestone, MN, in February. Part of the scope was megger/ttr/oil sample all transformers. The grounding transformers on the 35kV bus had FR3. Again, MN in Feb, but I was unable to draw a sample because the liquid filled transformer was a frozen FR3 filled unit. The units weren't energized yet. We were assured by ABB that is was OK and there was no cause for concern....


Thanks! appreciate the insight!


Down near freezing FR3 turns to the consistency of heavy slush. You won't be able to pump the transformers when cold, and the only way to sample them is to heat the sample valve.


Is it being used in Tap Changers also?


It is miscible with Rtemp and mineral oil If it is dark/very dark you can be almost certain something very bad has occurred. The color tells all with FR3. As others have noted, it will be nearly impossible to take oil samples in cold weather. Traditional power factor test values can not generally be used. Although, with such small units, I doubt you'll be power factor testing. All in all, there is no better fluid. It has the ability to pull moisture out of paper insulation. It has been noted by Cooper power that fr3 fluid can extend the insulation life of a transformer by as much as five to eight times. Fire point of 360° flash point of 330°C.


I heard FR3 was soybean based. We weren’t allowed to mix it with our draining of silicone or mineral oil. Stuff got thicker than a snicker when it cold as well like others have said.