Re: Phase Correction Caps

To: tesla-at-pupman-dot-com
Subject: Re: Phase Correction Caps
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
Date: Sat, 14 Sep 1996 19:03:22 -0700

Tesla List wrote:
> 
> >From rwall-at-ix-dot-netcom-dot-comSat Sep 14 15:43:36 1996
> Date: Sat, 14 Sep 1996 14:36:13 -0700
> From: Richard Wayne Wall <rwall-at-ix-dot-netcom-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Phase Correction Caps
> 
> 9/14/96
> 
> What is the voltage and capacitance of those power pole phase
> correction caps?  Could they be used as a filter cap after high voltage
> DC rectification?
> 
> RWW
The voltage depends on the voltage of the lines their connected to. The
capacitance is measured in KVARS (Kilovolt-amperes). If you know the
voltage and the KVAR rating, the capacitance can be easily computed:

  Let K = rating in KVAR
      V = Line Voltage in Kilovolts
      F = Frequency (Hz)
 Then C = (1000*K)/(6.28*F*(V^2))  in MicroFarads

Example: 
 A 10 KVAR cap, designed for 14.4 KV 60 Hz service would have a
capacitance of about 0.13 uF. If the cap was specified for 50 Hz
service, it would have a capacitance of 0.15 uF.

Although most are not well suited for Tesla work because of their
construction and lossy dielectric (typically paper or mylar), they are
excellent for DC, low frequency filters, or for Power Factor Correction
(obviously!). There are some manufacturers who are now beginning to use
more efficient dielectrics (polypropylene!), but these are quite new and
will not be the type you'd typically run into on the surplus market.
Even these still suffer from interconnection/termination construction
that is not ideal for high current, low inductance Tesla work. 

Safe coilin' to ya!

-- Bert --