Taking apart a large transformer

Jan 03, 2005 195 Replies

The 'm' is a leftover from the olden days, when it meant 'micro', not the metric standard 'milli'. Milli is not used in capacitor rating. Pico, micro then Farads. New capacitors would be probably marked with the 'u' instead of 'm'

So, they are 4100 microfarad capacitors

They are rated for

I don't know. Maybe Tantalum or Aluminium oxide?

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These guys found an interesting use for them:

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mike

If they are a metal can type they are most likely full of PCB oil unless stated otherwise on the metal cans.

I doubt they are 4 farads. More likely 4 microfarads uf.

YOU just needed to read his original post. He stated it pretty clear he was looking at laminations and windings and paper. If it even remotely was a oil filled transformer, it was a little late for that.

environmental

LOL...good luck with that one! We scrap surplus copper everyday in my business.

Gee wonder what a 8KW UPS is worth?

Probably more than you would get for it's parts at a scrapyard.

Just paid $120 for a 3KW and $100 for a 2.2KW APC rack mount units. Batteries were bad and sold as such.

Eight new batteries were just over $200 delivered.

Both units are up and running 24 / 7, one at our retail shop and one at our home both supporting a phone system and two Novell servers each.

Hugh

The historical aspect of this just HAS to be remembered.

================================================= Only metric prefixes for 10+6 or more have an upper-case abbreviation (e.g., M = 10+6, G = 10+9, etc.). In particular, note that the prefix m indicates

10-3 and M indicates 10+6. The difference between an upper-case M and a lower-case m is nine orders of magnitude! One should be warned that American manufacturers of capacitors often use "mF" or "MF" to indicate microfarads, a practice that is both incorrect and misleading.

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mike

A lot of that stuff is very carcinogenic when burned. The plastic coating on much of the wire causes great danger to living things when burned. Egg shells become very thin when the bird has been exposed to the burnt chemicals, so they break during nesting.

Please don't burn insulated wire or plastic. It's disgusting stuff AND now illegal in many places.

mike

I agree, it is a holy mess. m stands for milli. u stands for micro. n stands for nano.

i

I spent a multitude of hours as a kid taking stuff apart, including small transformers. (Dry types) Transformers are one of the least fun things to tear into.

With the size of the copper wire you say it has, it must have a high-amp output. Is it stepup or stepdown? If stepdown, it could possibly make a great custom arc or spot welder, or an electroplating supply.

Ken Grunke

Could not agree more. Pictures of both transformers (the big one and the isolation one) are at

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I just uploaded them.

I have no idea if it is step up or stepdown, looks like it is for many things.

i

Is a three phase unit ? - might be a great unit for two phase to three phase need or Wye to Delta or voltage to voltage work.

I used to use big ones on machines I wroked and designed on - wish I had one for just that.

Martin

Yes the PCB problem is related to oil filled transformers. if you can ID it you should be able to get the specs from the manufacturer to determine if it is oil filled or dry (maybe you already know). If it is dry then no problem. If oil filled and has PCB, make UPS take it back since they shouldn't have given or sold it to you.

I'm not Doug, but oil is used in larger transformer for cooling. PCBs were added to improve heat transfer. I have no idea what the smallest size of oil filled transformers are but larger ones are way bigger than 200 pounds. 8KVA may be a little small for an oil filled transformer.

These seem to be electrolytic capacitors rather than the oil filled type -- no PCBs.

Yup. The Municipality I used to work for had a whack of those ballasts and had to remove all from service. Triple bagged and stored in an old shed for 'future' disposal - read "when we figure out how we will let you know". The bags eventually disintigrated - the ballasts leaked and the whole damn shed became one embarassing toxic mess. Cost a small fortune to clean up the site and bury everything - including the shed. A nearby port faciliiy for the local pulp mill (Porpoise Harbour) had the distinction of being the most (PCBs) contaminated place in the Western World! PBBs are heavier than water - a convenient test of unknown oil - and the bottom of the harbour was covered with a (hopefully) sealing layer of clay. Nasty as they once said it is or not it, is still a worrysome substance.

Ken.

Geez ig. You sure stirred up a hornets' nest here. Getting to be one of those long (remembered) threads. BTW what program/workflow gets those photos on line so fast? I Emailed you at both addresses you posted but have had no reply. Still interested in that starter motor?

Regards. Ken.

If there is liquid in them and they date from before about 1973, then there's a good chance they do have PCBs in them. Check with the manufacturer.

--RC

"Sometimes history doesn't repeat itself. It just yells 'can't you remember anything I've told you?' and lets fly with a club. -- John W. Cambell Jr.

Those are capacitors, not transformers, however. (Which is only important because I was much less well informed about capacitors than I was about transformers?)

Are you sure about that? When I was with Arizona Public Service Co. in the late 70s they were in the process of replacing all their PCB-loaded transformers with non-PCB models. My understanding was that there was an EPA deadline they had to meet for the changeover.

--RC

"Sometimes history doesn't repeat itself. It just yells 'can't you remember anything I've told you?' and lets fly with a club. -- John W. Cambell Jr.

Forgive me, but the subject under discussion was _transformers_. The things in flourescent ballasts were capacitors.

--RC

"Sometimes history doesn't repeat itself. It just yells 'can't you remember anything I've told you?' and lets fly with a club. -- John W. Cambell Jr.

Nope. Not the old type, anyway. The ballast IS a transformer, and the old ones were filled with PCB. Those that don't have PCB's clearly state so.

Harold

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