Cutting open a coil

[Steve D.]

I had a coil failure and I'm curious to see what it looks like inside. Other than preparing for oil coming out, are ther any cautions or words of wisdom before I pull out my hack saw?

[Terry M.]

Re: Cutting open a coil

Be careful with that oil. Wear good rubber gloves and do not get any of the oil on your skin. I would wear a good respirator also, but I don't know what kind of filter to recommend -- thankfully, I am out of that business now days. DO NOT smoke or eat around that oil. I know that sounds extreme, but what is in that oil is really nasty stuff.

I suggest you look up PCBs on the Internet through your favorite search engine. This will get you started:

http://www.atsdr.cdc.gov/tfacts17.html

Edit add: I am not trying to be an alarmist. I handled this stuff daily for a number of years, but in the end we were trained in the basic precautions -- not so much in the beginning. In the automotive restoration hobby we routinely handle some not so pleasant products. A few basic precautions will allow us to live a lot longer and enjoy our rides for a whole lot longer.

[Michael B.]

Re: Cutting open a coil

I was once working on my car and had the ignition on for an extended amount of time. The points happened to be closed and it eventually overheated the coil which exploded like a volcano out of the top. The oil quickly dried to wax consistency. It was a mess to clean up. I would guess that the oil you find in a cold coil will be a semi-solid.

[Dan D.]

Re: Cutting open a coil

The oil used in old transformers (not just coils) contained PCBs. This stuff is not very nice. Just be careful and you will be okay. Don't know how tell you how to get rid of it. -Dan -

[Terry M.]

Re: Cutting open a coil

The oil used in old transformers (not just coils) contained PCBs. This stuff is not very nice. Just be careful and you will be okay. Don't know how tell you how to get rid of it. -Dan -

Old fluorescent ballasts contain PCBs also.

I deliberately avoided the issue of how to safely dispose of it. Trust me, you don't want to go there -- don't even think about it, unless your community has a "hazardous waste day" you are going to run into more trouble than you could ever imagine trying to properly dispose of it.

[Wayne W.]

Re: Cutting open a coil

You will not be able to tell anything really from breaking it open. The primary windings are obvious, but the secondary windings are micro hair in size and are so fine, you cant do anything with it except watch it frizz up as you strip it off.

[Jim T.]

Re: Cutting open a coil

I remember a conversation I had with a person knew about disposal of the old style oil filled transformers. If I remember correctly, there are only two locations in the Unites States that are licensed/capable/qualified to dispose of the electrical transformer's contents.

[Jean C.]

Re: Cutting open a coil

I can tell you first hand how the EPA feels about used transformer oil.

If through lack of knowledge of the EPA regs (I know, ignorance of the law is no excuse), you import a liter of used transformer oil that when new was USA origin and the used oil is destined for a lab in the USA for analysis and said liter of oil was imported without first obtaining a special import permit from the EPA, the monetary fine and paperwork will be of such magnitude that you will likely not make that error again. The culprit was as mentioned in other posts, PCB's.

Best regards

PS: The EPA got involved 3 to 4 years after the illegal import as a result of an EPA audit of the labs docs.

[Terry M.]

Re: Cutting open a coil

I remember a conversation I had with a person knew about disposal of the old style oil filled transformers. If I remember correctly, there are only two locations in the Unites States that are licensed/capable/qualified to dispose of the electrical transformer's contents.

I probably shouldn't state this publicly, but what the hey.

We sent thousands of perfectly good electrical transformers (10-feet by 10-feet by 4.5-feet wide) to a landfill in Georgia. The only thing wrong with them -- they contained PCBs as a fire retardant. Of course we replaced each one with a transformer with no PCBs. I don't know the cost, but it had to be many many millions. Some of these were lifted from buildings with heavy lift hellos. Others were lowered down elevator shafts. The easy ones were rolled out the door (the size of 10-foot high garage doors) onto trucks. It was an almost ten-year project for 50 to 150 people. At the end we issued a press release: “There are no more PCBs in the electrical transformers in Chicago.” Well, it was a little longer than that, and it did state the cost as I remember.

Edit add: Guys this is really nasty stuff, and I suggest you not bother cutting the coil open. Based on what Wayne says, which souds like the voice of experience, there is little to be gained.

[Wayne W.]

Re: Cutting open a coil

I posted pictures. Most auto coils are dry though.

[Steve D.]

Re: Cutting open a coil

Uhh..... I think I will pass on my science experiment, especially since Wayne posted the pictures of what I was trying to see.

Steve

[Steve D.]

Re: Cutting open a coil

Wayne

Thank you. Your photos have satisfied my curiosity.

Steve

[Terry M.]

Re: Cutting open a coil

Wayne,
From home I saw your text, but no pictures -- not even the red X. I guess I will have to look at this from home and see if I can figure out what is up.

The auto transformers we have -- about 30-feet high by 15-feet in diameter -- are not dry, but then we have radiators, pumps and fans. FOFA -- Forced Oil, Forced Air. They are are 138 Kv on the high side and 69Kv on the low side.