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Gentlemen, I am working on a coil that seems to be very close to what David has. It is based on a 10 kva pole transformer. I have built a current limiting ballast and have ganged varics so I can control current to around 40 amps an voltage up to 280. I am in the thinking phase for a SRSG and the tank capacitor. I have 3 capacitors like the ones in this discussion. They are way too high capacitance at 14 microfa. But I have questions about them for education on my part. They are rated at 7.2 kv but there is also a rating of 95 kv "bil". Can anyone tell me what the "bil" means? Also if I understand the post recently the two capacitors that David has in series is, .25 microfa. each for a total of .125 microf. That would be 125 nanof. Teddy On May 14, 2018 8:53 AM, "David Rieben" <drieben@xxxxxxx> wrote: > Oops, I fogot. the porimary voltage is from a 14.4 kV pig. > > ----- Original Message ----- From: "Andrew Cobaugh" < > andrew.cobaugh@xxxxxxxxx> > To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> > Sent: Sunday, May 13, 2018 8:50 PM > Subject: Re: [TCML] GE Protective Capacitors - Part # 9L18DCL101 or > 18L0009WH > > > David, >> >> How were you series'ing these for use in your system? Floating the case of >> one of them, or did you happen upon the dual bushing version? >> >> Also, what is the primary voltage on your system? >> >> >> On Sun, May 13, 2018 at 5:33 PM, David Rieben <drieben@xxxxxxx> wrote: >> >> Hi all, >>> >>> I was just wanting to pass on to the rest of the TCML big SG coilers the >>> amazing suitability that I have found of some certain GE Dielektrol >>> protective capacitors to be for coiling. These have been showing up on >>> eBay >>> fairly frequently as of late and are rated at 0.25 uFd @ 13,800 V(AC). >>> >>> https://www.ebay.com/itm/GE-Capacitor-with-Dielektrol-9L18DCL101-13-8KV/ >>> 171955634804?_trkparms=aid%3D777001%26algo%3DDISCO.FEED% >>> 26ao%3D1%26asc%3D50963%26meid%3Dfcbee251c09a4671967201c022e0 >>> 0f6c%26pid%3D100651%26rk%3D1%26rkt%3D1%26%26itm%3D171955634804&_trksid= >>> p2481888.c100651.m4497&_trkparms=pageci%3A4e91f1f4- >>> 56ef-11e8-bfd1-74dbd1800d55%7Cparentrq%3A5b4518781630a9c10cbe75cafff4 >>> bdba%7Ciid%3A1 >>> >>> https://www.ebay.com/itm/GE-General-Electric-Capacitor- >>> with-Dielektrol-Fluid-18L0009WH-13-800V/273049284524?_trkparms=aid% >>> 3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D50963%26meid% >>> 3D90ee9bc9263f44fe9a830e47dd8b0680%26pid%3D100675%26rk%3D1% >>> 26rkt%3D15%26sd%3D382430499481%26itm%3D273049284524&_trksid= >>> p2481888.c100675.m4236&_trkparms=pageci%3A4e91f1f4- >>> 56ef-11e8-bfd1-74dbd1800d55%7Cparentrq%3A5b4518781630a9c10cbe75cafff4 >>> bdba%7Ciid%3A1 >>> >>> This appears to be the best current 'deals' on these units at this time. >>> The original units (now discontinued from production) were PN - >>> 9L18DCL101 >>> and the updated ones are PN - 18L0009WH. Due to a GREAT eBay "deal" on >>> three of these last year, I decided to try a pair of these (the original >>> 9L18DCL101 units) in series (for 0.125 uFd @ 27,600 VAC - but measured C >>> is >>> just over 0.13 uFd) as the main primary circuit capacitor for my ARSG >>> driven, big pole pig coil. Once the primary coil was properly retuned for >>> the larger C than my original measured 0.113 uFd Maxwell pulse cap unit, >>> these worked quite beautifully in my coil! There appears to be no >>> discernable heating above ambient temperature of thier guts, although the >>> outer casing that is in closest proximity to the primary coil will get a >>> bit warm after an extended run, obviously due to magnetic heating of the >>> ferromagnetic outer casing, not losses of the internal dielectric >>> system. I >>> say this due to the fact that the discernab >>> le warmth of the outer casing completely disappears within a couple of >>> minutes following shutdown. From previous experience, I have found that >>> internal dielectric heating due to excessive dissipational losses that is >>> felt on the outer casing of the capacitor unit takes a considerable >>> amount >>> of time to fade after shutdown. Depending upon the internal thermal mass >>> of >>> the capcitor, this cool down can literally take hours! Even though they >>> are >>> 'used', I figure that I am actually running them at a pretty 'low stress' >>> level, pushing only an absolute maximum of 16.8 kVAC RMS (about 60% of >>> their combined 100% duty cycle nameplate rating and usually notably less >>> than this). >>> >>> It appears that these caps were designed to be used in combination with a >>> distribution surge arrestor to protect the windings of LARGE motors (that >>> run on a nominal input line voltage up to 13,800 volts!) from sharp line >>> voltage peaks. From what I have been able to determine online, they are >>> constructed with a PP based "Hazy Film" dielectric system and extended >>> end >>> foil connections and like most of their medium voltage PFC cousins, they >>> have internal discharge resistors to safely bleed off any residual HV >>> charge from the capacitor to the 'safe to handle' range within <10 >>> minutes >>> after the circuit is de-energized. This is a nice feauture in my opinion, >>> as it 'defangs the snake' of hidden residual charge that can creep back >>> up >>> to 'bite you' even after the terminals are shorted out with a hot-stick, >>> due to dielectric memory, yet their resistance level is still high enough >>> that their extra load across the cap's terminal is totally >>> inconsequential >>> to the coil's performance within >>> the milliseconds time frame of the charge/discharge cycling in a Tesla >>> coil primary circuit. >>> >>> All in all, these units appear to be constructed quite robustly, too, >>> both >>> from a mechanical as well as an electrical standpoint. So, if you happen >>> to >>> have spotted these particular caps and are apprehensive about taking the >>> leap, I can personally attest from a coiling standpoint that "the water >>> is >>> fine". ;^) >>> >>> David >>> _______________________________________________ >>> Tesla mailing list >>> Tesla@xxxxxxxxxxxxxxxxxx >>> https://www.pupman.com/mailman/listinfo/tesla >>> >>> >> >> >> -- >> andy >> _______________________________________________ >> Tesla mailing list >> Tesla@xxxxxxxxxxxxxxxxxx >> https://www.pupman.com/mailman/listinfo/tesla >> > > _______________________________________________ > Tesla mailing list > Tesla@xxxxxxxxxxxxxxxxxx > https://www.pupman.com/mailman/listinfo/tesla > _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxxxxxx https://www.pupman.com/mailman/listinfo/tesla