[ARC5] AC Motor Start Caps as Filters

[Roy Morgan]

Ken,

Your numbers make sense, but I would check with someone knowledgeable at the manufacturer before counting on my memory from years ago.  

Roy Morgan
K1LKY Western Mass

> On Mar 23, 2020, at 10:31 PM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:
> 
> On 23 Mar 2020 at 22:20, Roy Morgan wrote:
> 
>> 
>> I remember a report quite some time ago now from a fellow who spoke in person with an 
>> engineer at a manufacturer and asked about the dc rating of such capacitors. The engineer 
>> laughed and said the practical dc rating would be something like four times the peak of the rms 
>> ac rating.
> 
> OK. Then, if I have my figures correct, the peak AC rating for 125V RMS would be 1.414 X 
> 125 = about 176 V which X 4 = 707 VDC. So, 1200 MFD at 700 VDC.
> 
> Sounds like a darned good filter cap to me!!! :-)
> 
> Ken W7EKB