[ARC5] Electrolytics- How Much is Too Much

[Kenneth G. Gordon]

On 30 Jan 2013 at 5:59, David Stinson wrote:

> High Voltage electrolytics- how much current leakage
> at rated voltage is "too much?"

There have recently been published some details on allowable leakage in 
NEW electrolytics. I'll try to dig that out and publish it here soon. It varies with 
capacitance and voltage rating.

However, the permissable leakage for OLD electrolytics was different, 
higher, since those weren't as good as modern ones.

The apples and oranges thing...
 
> Say- I have an original can capacitor, 
> rated 40-40-40 at 450 volts.  
> After sitting with all three tied together and at
> 400 volts, total leakage was about 1.5. mA.

So to my way of thinking, that is too much. Think of it this way: P=EI: in this 
case, that is 0.6 watts of leakage, and the heat resulting from it.

Since the can is sealed up, that heat just sits there. After a while, the can 
should feel noticeably warm. I don't believe electrolytic caps should feel 
warm at all....but maybe that is just my own prejudices.

> only in what level of leakage is, in your opinion,
> acceptable in order to maintain a stock part in a set.

If that were my unit, I would replace it. Tom, at www.hayseedhamfest.com 
has FP can-type electrolytics of new manufacture, if you want to retain stock 
appearance. Otherwise, I would disconnect it, and install axial-leaded new 
ones under the deck....if there is room.

I believe the acceptable leakage would be that which would preclude the 
capacitor from getting warm enough to feel it.

Ken W7EKB