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Re: Halloween night, CP cap {con,de}struction

Tesla List wrote:
> 
> Original Poster: Ed Phillips <evp-at-pacbell-dot-net>
> 
> "Chip,
> 
> Sorry to hear about the death of your two caps! As you know, Condenser
> Products had apparently issued a recall for the batch of caps built as
> part of the last Tesla Builders group buy, apparently because of a
> manufacturing (or design?) defect. Do you happen to know which vintage
> yours were? CP applied some type of derating scheme to their caps, and
> claimed that the 20 KVDC ones should be good for use with a 14.4 kV pig
> source. However, if these were _actually_ 20 KVDC caps, this was
> probably not sufficient for the stress they'd actually see! I agree with
> John that they should actually rated for considerably higher voltage -
> more like 50 kV or above.
> 
> Good luck on the home-builts!
> 
> -- Bert "
> 
>         I bought a couple of those capacitors, and never got any details
on any
> recall.  Can anyone help?
> 
> Ed

Ed,

The only info I could dig up was an old posting to the List in October,
1996 from Don Froula. CP supposedly got back to Scotty Myers who was
going to contact the original purchasers. 

-- Bert --


Message Repeated:
================
>From froula-at-cig.mot-dot-comWed Oct 30 21:33:52 1996
Date: Wed, 30 Oct 1996 10:07:56 -0600
From: Don Froula <froula-at-cig.mot-dot-com>
To: tesla-at-pupman-dot-com
Subject: CP cap explosion analysis


I received a call from Condenser Products concerning the capacitor from
the group buy that had exploded in service.  They confirmed that it was
a manufacturing defect and will replace my unit as soon as a new one can
be built (about 6 weeks).

As can be seen from the photographs that I published on the WWW, there
are four rolled sections within the cap.  According to CP, one of the
sections had shorted internally, causing the casing to burst.  Two of
the other sections had what the engineer called "high IR", which he
interpreted to mean unacceptably high leakage.  The implication seemed
to be that there was a problem with either the construction or
dielectric material which caused this condition. The fourth section was
OK.

He said that he would contact Scott Myers, who coordinated the original
purchase, to discuss the situation with the remaining units.

Regards,

Don Froula