Taking apart a large transformer

Jon --

Let me try to answer your last question. I'm no transformer expert, but I worked in power plants my entire career. I know just enough to be dangerous.

Generally speaking, large power transformers used PCBs. The liquid in the transformer acted as a coolant that carried away heat to heat exhangers of one kind or another. Most of them rejected their heat to water or atmospheric air.

One of the ways to classify transformers is by their method of cooling. O/A were oil/air cooled. O/W were oil/water cooled O/A/F were oil/air/fan, etc. (I might be incorrect on that last one. It might be O/FA.)

The PCBs were valued for their fire-suppressant properties. Thus, if a transformer ever blew up there wasn't so much danger of fire.

Long before the days of environmental consciousness, folks who could get their hands on transformer oil (PCBs) would slather it onto the wood shingles on their houses. Not only would it help preserve the wood, it would act as a fire supressant.

Regards,

Orrin

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The blue ones? They are not 4.1 farad. You might call them 4.1 millifarad, but the common way to say it is 4100 uF (micro-Farad).

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Those don't. They are DC electrolytic capacitors, not oil-filled ones.

However, the ones in the background are oil-filled (The ones with all-metal oval cases.)

The date of manufacture of the blue ones is the 11th week of

1991, long after the PCBs were no longer used. The oil-filled capacitors are almost certainly of the same period (as is the whole UPS). And Best (the maker of the FerrUPS) would not use old PCB-laden capacitors, even if they had some in an old storeroom. But they would not, as the company was formed well after PCBs stopped being used in capacitors or oil-cooled transformers.

Well ... actually, they *did* use *some* PCBs in their UPS. Printed Circuit Boards, not the chemical. :-)

Enjoy, DoN.

Insulated square copper wires from a dry transformer are not 99% copper and take a lot of work to remove the insulation.

I have tonnes of insulated copper wire if you want it. I think you could almost have for the picking it up. How many bins can you take per year?

Just don't ever lose weight. Toxins are stored in your fat cells.

Actually, there was a real good clue, as he described the visual appearance of the windings - which is pretty difficult if the windings are inside a can full of oil.

And now you've got a PCB-laden Superfund Site on your roof. :-0

("Well, it sure sounded like a good idea at the time...") ^_^

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Where do I send the contribution? They may need more ammo.

mike

Thanks Don! The little ones say no PCB.

i

The railroads used old PCB oil to keep there ties preserved and there gravel from dusting.

This just implies that he posted information without even knowing much about the subject matter. This wreaks of M II again. This is her style.

LOL. These are standard electrolytic capacitors and have no PCBs in them!

However the metal cans at the back may have. Careful with them.

Friend of mine used to harvest the coils off the back of picture tubes from TV's. He'd smash the black iron out with a hammer, and compact t he copper parts.

I've work with tranformers for over 27 years, and most them are I filled. I've seen lots of windings and laminations, its pretty easy once they come out of their tank.

regards,

John

Simply add Tin and you have a Bronze of some sort. Copper is worth it to me. I have a fist with of backplane buss line copper that is 1/8 to 1/4" thick. So after I move, I'll buy some TIN from a Solder company or sorts and make Bronze.

Mart> Insulated square copper wires from a dry transformer are not 99% copper and

Many MIL Spec transformers had the very high quality - thin oil that was extracted by many people for use when the transformer burnt - and that was an issue.

Power companies did go through changes - it was costly and over the length of time it was useful. Lighting strikes and line over use issues blew transformers from time to time and you could hear the can top blow and smell the burnt oil knowing exactly what happened.

Just to risky to be on the pole of every or every other house.

I can't wait to relocate - I have two mongo transformers that supply my house and my shop. One each.

Martin

Speaking from the position of a guy that, as a kid, did one hell of a lot of copper wire recycling------that's how I made my money-------------------

For someone that claims to be recycling copper on a daily basis, you don't appear to know much about copper. *ANY* copper wire that is used for electrical purposes is electrolytically refined copper. It must have excellent electrical properties in order to be used, and also to be drawn successfully. It is by the electrolytic refining that copper attains that level of quality. It's also necessary for the refinery, for copper, as extracted from ores, is typically the carrier of other elements, many of which are valuable (gold, silver, platinum, palladium, etc.) and it is in the electrolytic process that they are recovered. It would be absurd, at best, to assume that copper wire isn't pure, unless it is alloyed to specifics for a given purpose.

If, in the process of making connections, the copper has tinned ends, the copper is used in the brass industry for alloying to their specifications, so the recycling market still has a keen interest in buying it. There is *always* a market for recycled copper, it is never worthless as you suggest. If you're not getting paid near market price, it's your own shortcoming that is preventing you from doing so. You're being taken for a ride and don't know it. Maybe you need to step up to the plate and get an education.

If you have anything in the way of links to lead me to information contrary to this, feel free to provide them. I'm not interested in your opinion. You've already shown us that you don't have a grasp on reality and don't know what the hell you're talking about.

Harold

5% each zinc, tin and lead makes the classic semired brass/bronze. Up to 22% tin (alone) makes a hard bell bronze. Up to 30% Pb (alone or with others) will make a frothy bearing bronze. Up to 35% zinc makes brass, much more and you get white (beta) brass, aka muntz I think.

By which you mean liberal application of less than a dollar of propane? I'm all for that...

Is that thin stuff or house wiring? Insulated or enameled? How much is shipping say 50lbs to 53511?

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

Energy stored in a capacitor E = 0.5 * C * V^2, so a 100uF cap charged to

100V stores a quarter of the energy of one charged to 200V. 1F charged to 16V = 128J stored. A capacitor charged to 250V storing the same energy would be 0.004F = 4mF = 4000uF (more exactly, µF if that extended character shows up). Of course, the voltage and capacitance (among other specs) have other electrical importance, depending on use. :)

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @