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Re: power factor correction capacitors (fwd)

---------- Forwarded message ----------
Date: Sun, 01 Jul 2007 12:33:25 -0400
From: David Speck <dave@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: power factor correction capacitors (fwd)


IMHO, it's not worth it to try to build a PFC cap.  You can get metal 
can (oval or round) oil filled motor run caps for free from dead air 
conditioners, refrigerators, some furnaces, or dehumidifiers at your 
local recycling center.  Usually, the bigger the original device, the 
bigger the cap.  They are also available from eBay.  Even microwave oven 
caps work, but at only 1 uF each, you would need several in parallel.  
Motor run caps will have a definite capacitance value, like 6 uF at some 
voltage, stamped into the case. 

Do not use round black plastic encased electrolytic motor start caps -- 
they are intended for a duty cycle of only a few seconds, and get hot 
and explode if run continuously.  Start caps usually have a very wide 
range of capacitance printed on the case, like 50 - 120 uF at some 

> Hey everybody,
>      Can anybody tell me where I can get, some capacitors to use for power 
> factor correction (and how much it would cost me)?  Would it be insanely 
> difficult to build one?  Could I use motor start or run capacitors?  Thanks.