PCB Filled Transformers
PCB Filled Transformers
(OP)
The plant that I work at has several PCB transformers that we are planning to replace or retro-fill. I have heard some sketchy things about Retro-filling that make me question the process and end results.
I’m wondering what information or practical experience others have had with retro-filling?
More General Info that might be important:
The replaced X-fmrs are dry type.
Most transformers that need replacing are 6.9kV Y to 480V Delta (KW vary)
Some are in hard to reach locations.
Most transformers are in continual use.
Some are in pretty nice climates, but most are operated in a harsh temperature environment (100 + F).
All the transformers are about 20 years of age.
Thanks,
nasmith
I’m wondering what information or practical experience others have had with retro-filling?
More General Info that might be important:
The replaced X-fmrs are dry type.
Most transformers that need replacing are 6.9kV Y to 480V Delta (KW vary)
Some are in hard to reach locations.
Most transformers are in continual use.
Some are in pretty nice climates, but most are operated in a harsh temperature environment (100 + F).
All the transformers are about 20 years of age.
Thanks,
nasmith






RE: PCB Filled Transformers
In most cases, resolution depends a lot on region, site process, potential to public exposure, transformer operating status, vessel condition and concentration in insulating fluid.
One reference is http://www.epa.gov/opptintr/pcb/
Contracting with a specialized service firm may be a cost-effective approach. Regulatory aspects have sort of “leveled off” in the last two decades but are still quite complex to the uninitiated.
RE: PCB Filled Transformers
RE: PCB Filled Transformers
Replace them while it is still your choice.
RE: PCB Filled Transformers
If the transformers are only contaminated, (ie mineral oil that was contaminated at some time) then retro filling is very economical, but still may take a couple of runs to get it below contaminated levels depending on level of contamination.
I would also suggest looking at Silicone or R-Temp filled transformers as replacements vs. dry type, they are generally cheaper and smaller, and less sensitive to enviromental conditions.
RE: PCB Filled Transformers
http://www.nttworldwide.com/tech2308.htm
for PCB Dilemma
RE: PCB Filled Transformers
Let me give some more information:
• Because of whom the company is owned by and because of what the generation plant is the goal for PCB reduction per transformer is less than 2 ppm.
• We have two other generating plants similar to the one I work at that have both have had PCB replacements (we have not). One done years ago and one done recently. The one done years ago has probably leached out above the PCB limit, since they no longer test the transformer oil I have no way of knowing. The one done recently was attached to the leaching device for a longer period of time (years). I have calls into my counter parts at both plants, but like the rest of the world, they are covered up and haven’t responded yet.
• Interesting enough the group we have been dealing with is not the website by Stevenal, and I was under the impression the company we are dealing with was the only company in the business. I’ll also ask our purchasing group if we have looked at SDMyers.
• I’ve been told by our design group and others that retro-filling will degrade our transformers, shorten the life, and will decrease the load our transformers can handle.
Please keep the comments coming, and if anyone has had a transformer retro-filled, I’d love to hear from you…
RE: PCB Filled Transformers
See the follwing links:
http://www.cooperpower.com/library/pdf/92006.pdf
http://www.dowcorning.com/content/power/powerfire/default.asp
http://www.ecmweb.com/ar/electric_analyzing_transformer_insulating/
http://www.ec.gc.ca/pcb/eng/pub_e3.htm
RE: PCB Filled Transformers
RE: PCB Filled Transformers
I think replacing the transformers is the way to go -- a couple of items to check: a) if you retrofil, check the level of PCB's immediately after retrofil by an independent lab for acceptance (or as a double check) even though the retrofiller is a well known, establihed firm that will analyze the stuff [yeah, right -- if they know they'll be audited, you'll get a better job done]... b) check on viability of silicon, I've heard rumor that it (won't breakdown and) is being treated as hazardous also (our recycler wouldn't touch a silicon filled transformer)
c) if you select a dry type, make sure the environment it sits in is not detrimental to the insulating qualities of the transformer AND check the impedance of the proposed transformer -- those quoted to us were significantly different from the oil-filled