Cydrome Leader wrote:

Pete C. wrote:
Eric R Snow wrote:

On Sun, 16 Oct 2005 19:11:32 +1000, "john johnson"
wrote:


"william_b_noble" wrote in message
news:1129443990.371761fa123e7cca0b6df5fa678f46c1@ teranews...
high voltage mica caps aren't hard to find, I have a 30,000 VAC mica cap
sitting here at this moment - it's about 8 inches X 6 inches X 12 inches,
with a 8 inch insulator on top, the case is one terminal, the other is on
top of the insulator.

I suspect your TIG welder needs a lower voltage.

Mica has particular dielectric benefits in certain frequency bands - and
oil dripping out is not a real problem, jsut remove the cap, refill with
oil and seal it again. use mineral oil if you can't find capacitor oil.

Just make sure it's oil in there, not PCB. What vintage is the machine?

regards,

John

The machine was built in the early seventies. Were PCBs used then? I
think they were. If they are leaking PCBs then wouldn't the best fix
be just re-filling with non PCB oil and sealing them? I could take
them to the county as hazmat but then they would have to deal with
them.
ERS

It the cap does not have "no PCBs" printed on it than it can be assumed
to contain PCBs which means you've got a bit of a problem on your hands
if it leaked.

You could also assume it's full of gold, but that's wrong too.

I believe that all fluorescent ballasts, oil filled capacitors and oil
filled transformers manufactured since the ban on PCBs are required by
law to state "no PCBs". Presumably there may have been some transition
period where non-PCB units may not have been marked, but it should be a
reasonably safe assumption that if it doesn't say "no PCBs" it likely
has some level of PCBs.

From: http://www.epa.gov/opptintr/pcb/2003pt761.txt

[63 FR 35443, June 29, 1998]

Subpart C--Marking of PCBs and PCB Items

Sec. 761.40 Marking requirements.

(g) Each large low voltage capacitor, each small capacitor normally
used in alternating current circuits, and each fluorescent light ballast
manufactured (``manufactured'', for purposes of this sentence, means
built) between July 1, 1978 and July 1, 1998 that do not contain PCBs
shall be marked by the manufacturer at the time of manufacture with the
statement, ``No PCBs''. The mark shall be of similar durability and
readability as other marking that indicate electrical information, part
numbers, or the manufacturer's name. For purposes of this paragraph
marking requirement only is applicable to items built domestically or
abroad after June 30, 1978.



Pete C.