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Re: [TCML] Looking for info on GE 30F series capacitors

Hi Andrew,

These capacitors date back to the 1980's. The good news is that they contain no PCB's. They use polypropylene film-kraft-foil construction. This predates newer "hazy film" polypropylene-foil dielectric systems. They are suitable for low duty cycle pulse forming networks and DC filtering applications. They will get warm in any RF application due to the lossy kraft paper layer. They have relatively long, high-inductance insulators instead of the flat low-inductance "dog bowl" insulators used in true high-current energy discharge caps.

These caps are NOT built to handle the high peak currents involved in coin shrinking. I only know about their internal construction since I autopsied one after it failed - in coin-shrinking use. The first capacitors I used for shrinking were some surplus 54uF 15kVDC GE units (GE 30F1600). I acquired these in 1997. I also contacted GE engineering and they couldn't provide me with ANY specs or information on them even back then! Finding any specs on them today is likely an exercise in futility.

I began trying to use three of them in parallel to shrink coins. Unfortunately, the caps began failing (losing capacitance) after 30 shots. One then catastrophically failed in less than 50 shots. The metal case ruptured, disgorging a gallon or so of nasty blackish fluid and foil fragments onto the indoor-outdoor carpeting. The impregnant is a solvent - it immediately ate the backing off the carpet and soaked the concrete below.

An autopsy indicated that the capacitor was designed with a hairpin loop in one of the capacitor buses. Each time the capacitor was discharged, magnetic forces flexed the loop, quickly ripping the bus from the capacitor rolls at the solder joints, causing internal arcing, and eventual an internal explosion.

I would not use these for any high current (kA-level) discharges, but YMMV. Otherwise they are dated, but pretty good pulse or DC filter caps.

Good luck and best wishes,

Bert Hickman
Stoneridge Engineering LLC
+1 630-964-2699
World's source for "Captured Lightning" Lichtenberg Figure sculptures,
magnetically "shrunken" coins, and scarce/out of print technical books

Andrew Cobaugh wrote:
Please excuse the off-topic-ness of the post, but I'm hoping someone on
this list can help me out.

I am looking for information, hopefully datasheets, on some high voltage
capacitors that are long since discontinued. I have looked online and
cannot find any references to them. They are series 30F. These are the
catalog numbers and nameplate specs.

30F1427 3.3uF 10000VDC
30F1427 5uF 10000VDC
30F1431 13uF 10000VDC
30F1404  46uF 5000VDC

I contacted GE and the person that responded claimed they had no record of

They're large, rectangular, oil filled with dual ceramic bushings. I have a
bunch of these, and was hoping to use them to make a small can crusher or
exploding wire rig.

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