[Amps] Hi pot test - normal leakage current of vacuum cap

[Dan Hearn]

OM: I have a commercial Hipot tester which can be varied from 0 to 9kv. I
tested several vac variables I have and here are the leakage results.
1. 1000pf @ 5kv. 1ua at 5kv, 5ua @ 7.5kv.
2. 1000pf @ 3kv. 1/2 ua at 3kv, 4ua @ 4.5 kv.
3. 1000pf @ 3kv, 1/2 ua at 3kv, 6ua @ 5.5 kv.
4. 300pf   @ 15kv 3 ua at 3kv and current flickers. 25ua @ 4.5kv,  bad
unit.
All are Jenning units. I see increasing leakage current a bit above the
rated voltage on good caps. I would never increase the voltage until it arcs
because
I am concerned that an arc will damage the smooth surface. The increasing
leakage current, I believe, will separate a bad cap from a good one.

73, Dan, N5AR

On Sat, Oct 8, 2011 at 6:05 AM, LB3HC <rezycle.bin at gmail.com> wrote:

> Hi experts! I have hipot tested a 1000pF UR4LL vacuum capacitor today.
> It did clunk a couple of times at approx 4 kV and then it settled
> down. The it clunked a couple times at 8 kV and settled down. Now it
> handles 14 KV without any internal arc overs. However... it draws
> approx 50 uA leakage current @ 14KV. Is that normal or do I have a bad
> vacuum (gassy cap) here?
>
> 73
> LB3HC
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-- 
Dan Hearn
N5AR