[Amps] Test versus working voltage for oil filled capacitor

[Alan Ibbetson]

My original post had a misleading typo: my capacitors weigh 10Kg not 
10lb each. Sorry. They sound very similar to the CDE ones from Henry 
that Jim describes.

I have tested each unit for temperature rise when carrying 3A ripple 
current at 50Hz, using a carefully fused variac on UK mains. I clamped a 
temperature probe to the case for hands-free measurement. The bottom 
line is I can't see any temperature rise in one hour - confirmed by hand 
after removing the mains connection. I don't doubt these things are not 
purpose made for HT PSU applications but as far as ripple current goes 
they seem fine.

I do not yet have the means to charge the caps to 3KV in finite time for 
hi-potting so I will need to scratch build a PSU using a junk box 
transformer I have.

Thanks to everyone for your help.

73, Alan G3XAQ

On 15/04/2015 14:38, Jim Thomson wrote:
> ##  They will run fine at 3 kv no load.   Dunno about 2A ripple current though.
> They are light.  Mine were from henry radio, made by CDE.   8 x 4 x 12  and weighed
> 30 lbs each, rated at 42 uf @ 4500 V.     Mount them vertically.
> Also insulate them from any metal chassis, and metal sidewalls....and also from
> the 2nd oil cap.     IE:   Treat them  like hv electrolytics.  If you see oil stating to leak
> around the insulators, stop using them.  Your caps are no doubt pulse type rated caps,
> and they usually have high ESR.  On any pulse rated oil cap, don’t runt them at any more than
> 60% of their stamped rating.
>
> Jim  VE7RF