Re: GE 42L series capacitors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jon Rosenstiel by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jonr-at-pacbell-dot-net>

I am using 0.22uF at 2000V 42L series caps on my 5kVA 14400V pig powered
coil. I first tried 20 caps/string, but they got warm quickly and a couple
of them blew out the end connections. I then went to 30 caps/string and have
had no problems since. (I think in my case my arc welder ballast produces a
pretty large "inductive kick", so the caps see a lot higher voltage than the
14400V xfmr rating would indicate).

I also use "Terry's" 0.056uF Panasonic caps on the same coil. To get the
Panasonics to survive I had to use 15caps/string. I had originally tried
10caps/string, but after just a couple of minutes they overheated and blew
out the sides of the caps!

(Actually I am now using both types of caps, 5 strings of Panasonics in
parallel with one string of the 42L's).

In my original failed strings the Panasonic caps seemed to get hot all over
but the GE caps just got hot on the ends. (I suspect the 42L's don't have
that great of an end connection).

I'd recommend that you build just one string and test it with your setup if
you can. Might save a lot of grief and time down the road.

As they say, "your mileage may vary"!

Jon Rosenstiel





> Original poster: "Matt Whitman by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<teslacoiler-at-hotmail-dot-com>
>
> Hi all. There has been some talk about the questionable reliability of the
GE
> 42L series caps.

<snip>