Re: control panel measurments

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

At 04:05 PM 2/27/2004 -0700, you wrote:
>Original poster: "Luke" <Bluu-at-cox-dot-net>
>I recently saw a device in C Crane catalog.
>It was called the Kill A Watt.  It is something you plug into the wall and 
>then plug something into it.
>The literature stated it could measure the volts, amps, watts and 
>frequency.  It also said it could measure the power factor and VA of what 
>ever was pluged into it.
>
>This raises a couple questions.
>First what technically is the difference between VA and watts?  I thought 
>it was the same thing.

Nope.. VA = rms volts * rms amps which may be larger than watts, which is 
the average of the instantaneous product of voltage and current. VA is also 
called "apparent power" and watts is "true power" or "active power"

>Or does one have to do with power factor?

Yep... Watts = pf * VA

>Is power the apparent power (not taking the power factor into 
>consideration and VA the real power or vice versa?
>Or is there something else I am missing on this?
>
>
>The next question is can I build a control panel that will give me these 
>values for my TC?
>What I would like to see on my panel is measurements of the primary side 
>of my NST bank.
>The values would be volts, amps, true power, apparent power and the power 
>factor.
>If it is a huge undertaking

Wire a Kill-A-Watt into your control panel... They're about $30 or so.