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Title: Question about HV Capacitor mounting Post by: KC8OPP on March 16, 2005, 07:02:54 PM I have a couple of Sangamo oil filled caps that I am using for a new linear amp project. They are 4mfd @ 5K wvdc. They are about 4 inches square and 12 inches to the top of the terminals. The caps are pulls out of an old FM BC rig and appear to work fine on the bench when I tested the supply. These caps were mounted with there terminals up.
Now in this new life it would be easier for me to mount they laying down or even up-side down. Anyone ever done this with oil filled caps? Should I have any concerns about their innerds shifting and letting out the smoke. What say the learned masses? Roger KC8OPP Title: Question about HV Capacitor mounting Post by: WD8BIL on March 16, 2005, 08:59:04 PM Well Roger... I've seen oilies mounted on their sides in many a rig and applications. The Viking 1 and 2 have one for the plate supply mounted lying down. don't think that's too much a problem.
I ain't even gonna take a stab at the upside down bit though. Never seen it. just my 2 cent Title: Question about HV Capacitor mounting Post by: KL7OF on March 16, 2005, 09:37:34 PM Turn it upside down on your bench for a few days......If the stuff stays inside on the bench it should stay inside in the rig. I cut some oilers open when I was a kid .....and the oily layered stuff inside won't care what position it is in............
Title: Question about HV Capacitor mounting Post by: K6IC on March 17, 2005, 01:55:18 AM The T-368 runs its two oil caps with the terminals down -- through a chassis. Think that this is "upsidedown" in Tom's terminology. Think that most BC rigs run oil caps with terminals up. I have never seen orientation of large oil caps speced.
GL Vic KF6RIP Title: Question about HV Capacitor mounting Post by: KA7IUS on March 17, 2005, 06:14:28 AM Hello Everyone,
I have mounted caps (up side down) before. What I do, is lay a heavy bead of silicon caulking around the high voltage termanals 1st. Hopefully they won't leak. The silicon also provides some HV protection with the chassis. TONY Title: Question about HV Capacitor mounting Post by: W3BYM on March 17, 2005, 07:32:57 AM HI Roger...My 813 rig runs one 30uf @ 5KV. It has been laying on its side for a couple years now. BTW I mounted it with a couple very large radiator screw clamps from that "other" hobby.
73 Tom Title: Question about HV Capacitor mounting Post by: KC8OPP on March 18, 2005, 06:19:42 AM Thanks for the input guys. I was concerned because these caps have spent years with the terminals up.
The plan now is to make a mounting shelf with openings for the terminals pointing down. This way all of the HV wiring will be very close. Tom, good idea with the radiator clamps, but think that I will use the factory hold-downs that came with the caps. Back to drilling and blasting! 73's Roger KC8OPP Title: Question about HV Capacitor mounting Post by: k4kyv on March 18, 2005, 07:56:09 PM I don't think it matters which way HV oil caps are mounted. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
The only problem with mounting them terminals down is oil (PCB) leakage. From my experience, oil caps are almost indestructible, but they do tend to develop leaks around the terminals as they age. Occasionally they short out. I had one to go in my Gates BC1-T and it almost burnt out the 10 hy 100 ma LV filter choke that filters the DC to one of the driver boards. |