RE: Ok.. where am I going wrong

To: tesla-at-pupman-dot-com
Subject: RE: Ok.. where am I going wrong
From: "Payne, Will E" <will.e.payne-at-lmco-dot-com> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Mon, 16 Nov 1998 11:52:33 -0700
Approved: terryf-at-verinet-dot-com


Howdy !

	My meters gave very doubtful readings, mainly reading WAAAYYY high
due to the horrible waveform in the mains circuit.  I have resorted to
calorimetry to measure my primary current, and it seemd to be pretty
accurate.  
	The resistance in my ballast bank is electric hot water elements in
a 5 gal plastic bucket.  I measure the temp before and after a 10 min run
with a candy thermometer.  Then I measure again 10 min later to
approximately account for heat lost during the run.  Turns out my bucket
heats much faster than it cools, so the correction is fairly small.  I stir
the water to prevent a very hot layer forming at the top and boiling off.
One could try to measure liquid level before and after to account for
vaporization, but I dont.
	Built an Excel spreadsheet to find the Joules and current, etc.  I
take 5 gal of water, plus 2 kg of iron is my estimated thermal mass.  I find
the results to be in good agreement with how often by 20 A main breaker
blows.  My biggest unknown is the phase angle.  This could be estimated with
a scope.

Will