RE: MMC or Maxwell? Which is better (Condensor Products)?

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

In thirty-something year's experience of dealing with electronic
faults, I have observed that somewhere in the vicinity of 80%+ of all
faults are due to poor or failed connections of one kind or another,
be they soldered, crimped, contact, wrapped etc. Types of failures
include improperly tightened screws/nuts, dry joints, joints not even
soldered in the first place (not showing up initially because good
practice had been followed by ensuring a sound mechanical fixing
prior to soldering), corrosion between pressure points, poor quality
soldering (quite common a few years ago), solder cracked around the
periphery of wires subject to thermal stresses (often as a result of
poor tinning and/or not enought solder in the first place), and
others I can't think of on the spur of the moment. Pressure-contacts
under oil sounds like a no-brainer to me.

Malcolm

On 29 Feb 2004, at 11:53, Tesla list wrote:

 > Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>
 >
 > Hi,
 >
 > Chips caps were not solidly strapped together.  The ends of the packs
 > were just pressed together I think with a spring.  The press contact
 > in oil seemed to be where it all went bad.  I hear they replaced many
 > under warranty and even said there was a problem, but I don't know if
 > they ever confirmed what it exactly was.  Not to blame CP, they did
 > everything they could to make it right...  With an NST system and much
 > lower peak and RMS currents, I think they would have done just fine.
 > It is very possible they were not aware of the peak and RMS currents
 > needed in pig systems when they made the caps and thus made them too
 > weak...
 >
 > Cheers,
 >
 >          Terry
 >
 >
 > At 10:29 PM 2/28/2004, you wrote:
 > >Hi Terry, what do you mean by "casually" connected together? I
 > >understand that they (at least mine) were made of 6 series caps. Oh
 > >and Ed if you read this, make sure that you roll the cap every month
 > >(before using it) or so to prevent "drying" of the dielectric due to
 > >an air bubble.
 > >
 > >No need to get rid of those commercial caps, just use them as
 > >designed. And when they go, build a MMC!
 > >
 > >Regards,
 > >
 > >David Trimmell
 > >
 > >-----Original Message-----
 > >From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > >Sent: Saturday, February 28, 2004 8:39 PM
 > >To: tesla-at-pupman-dot-com
 > >Subject: RE: MMC or Maxwell? Which is better?
 > >
 > >Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>
 > >
 > >Hi,
 > >
 > >I saw one of Chips blown caps that I "think" was involved in all
 > >this. The caps had several sections that were connected together
 > >"casually" so RMS
 > >
 > >current and peak currents were the problems.  In a mild NST system,
 > >they
 > >
 > >may very well do just fine.  Chip blew his with a pig system and a
 > >gap with a ton of points and a 10,000 RPM motor....  I would think
 > >and NST system
 > >
 > >would have a hard time blowing one.
 > >
 > >Cheers,
 > >
 > >          Terry
 > >
 > >
 > >At 07:34 PM 2/28/2004, you wrote:
 > > >Ed, that sounds just like one of the CP caps. I bought the 15KV one
 > > >because I could only afford the $160 for it at the time. My
 > > >experience has been good. But I would be interested to know if
 > > >others had failures while running in a sensible Neon system? I
 > > >would say use it! Like I said, the Geek MMC caps are great, but no
 > > >need to feel you shouldn't
 > >use
 > > >your existing Condenser Products cap that was also designed to be
 > > >used in sensible static gaps coil.
 > > >
 > > >Regards,
 > > >
 > > >David Trimmell
 > > >
 > > >-----Original Message-----
 > > >From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > > >Sent: Saturday, February 28, 2004 5:26 PM
 > > >To: tesla-at-pupman-dot-com
 > > >Subject: Re: MMC or Maxwell? Which is better?
 > > >
 > > >Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 > > >
 > > >"Ed, all, IF you are talking about the CP caps, then I have one, a
 > > >.02uF-at-15KV, that has had many hours of use*. Condenser Products
 > > >never intended (designed) this series of caps for >120 PPS (static
 > > >gap). Failures were mostly on Pig coils >120PPS. Please correct me
 > > >if I am wrong. MMC's are great, but the CP caps got a bad rap in my
 > > >opinion. I talked to one of their engineers about this, and he was
 > > >sure that on NEON systems with STATIC gaps the caps should do very
 > > >well... Unfortunately they only mentioned the 120PPS thing that was
 > > >not followed...
 > > >
 > > >David Trimmell"
 > > >
 > > >         I just went looking for the ones I have but there's been
 > > >         too
 > > >much stuff
 > > >piled into my attic since the last time I saw them.  I thought that
 > >they
 > > >were 0.025, 20 kV, but guess memory is short these days.  My only
 > > >interest was in using them with NST's (no interest in bigger and
 > > >better things) and have always used both a fixed gap and a safety
 > > >gap.
 > > >
 > > >         Sounds as if you feel these are OK under such
 > > >         circumstances?
 > > >
 > > >Ed
 >
 >
 >