high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
JonIverson, Sun Oct 20 2019, 12:56PMMy project involves a small high voltage transformer with a 6x6x6 inch PVC junction box as housing. The transformer will be under mineral oil, so the housing will be completely filled with the oil. Four connections will be needed through the box, two for transformer primary side and two high voltage output. Output will be up to 5" sparks between two rods (much set up like an old spark coil). I had planned on using solid 18-20 gauge wire for all connections (with insulated high voltage rated wire for the HV outputs). What's the best way to seal the wire feedthrough areas (all 18-20 ga solid wire fed through) so that there are no leaks down the road? Thank you.
Re: high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
Sulaiman, Sun Oct 20 2019, 01:30PM
Wires through holes often fail due to frequent bending,
I'd use 4mm binding posts
and araldite (epoxy resin) them in place.
Also, oil can often creep along the wire inside the insulation.
You could use a little ingenuity plus automotive spark plugs for the eht feed-through connectors if you are concerned about flashovers.
Sulaiman, Sun Oct 20 2019, 01:30PM
Wires through holes often fail due to frequent bending,
I'd use 4mm binding posts
and araldite (epoxy resin) them in place.
Also, oil can often creep along the wire inside the insulation.
You could use a little ingenuity plus automotive spark plugs for the eht feed-through connectors if you are concerned about flashovers.
Re: high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
Patrick, Sun Oct 20 2019, 06:38PM
this is best:
Patrick, Sun Oct 20 2019, 06:38PM
this is best:
Re: high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
JonIverson, Sun Oct 20 2019, 06:44PM
Patrick, it's interesting you posted that and on the same site where I just uploaded mine:
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What you've shown is most likely how I will proceed. You can see in the photos that that is basically how I did it the last time except I used solid wire feedthrough and not screws. This time I'm going to use screws.
I was thinking of the spark plug idea mentioned above because there is a lot of leakage which was the reason for so much silicone, but maybe I'll just do like I did before except use the screws.
JonIverson, Sun Oct 20 2019, 06:44PM
Patrick, it's interesting you posted that and on the same site where I just uploaded mine:
*
What you've shown is most likely how I will proceed. You can see in the photos that that is basically how I did it the last time except I used solid wire feedthrough and not screws. This time I'm going to use screws.
I was thinking of the spark plug idea mentioned above because there is a lot of leakage which was the reason for so much silicone, but maybe I'll just do like I did before except use the screws.
Re: high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
Patrick, Mon Oct 21 2019, 08:19AM
you can look here, i used plumbing parts for some sealing pass-throughs.
Patrick, Mon Oct 21 2019, 08:19AM
you can look here, i used plumbing parts for some sealing pass-throughs.
Re: high voltage wire feedthrough sealing suggestions for PVC box filled with mineral oil?
JonIverson, Mon Oct 21 2019, 03:07PM
That's very interesting, Patrick, and looks like you did that project some time ago. It prompted me to check out a HV probe I also built around the same time that uses a string of resistors inside a long oil filled PVC pipe. I used it with a DVM to check up to 100 KV supplies. I had forgotten about it, but looking at it today, it has never leaked. I have had it sitting horizontally on the shelf all these years. The high voltage probe output side was just had a piece of coathanger wire epoxied in place and 40 KV TV wire for the low side, also epoxied in place. It you hadn't of shared yours, I would never have thought about mine so thanks.
JonIverson, Mon Oct 21 2019, 03:07PM
That's very interesting, Patrick, and looks like you did that project some time ago. It prompted me to check out a HV probe I also built around the same time that uses a string of resistors inside a long oil filled PVC pipe. I used it with a DVM to check up to 100 KV supplies. I had forgotten about it, but looking at it today, it has never leaked. I have had it sitting horizontally on the shelf all these years. The high voltage probe output side was just had a piece of coathanger wire epoxied in place and 40 KV TV wire for the low side, also epoxied in place. It you hadn't of shared yours, I would never have thought about mine so thanks.
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