Re: Getting more input power

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

Original poster: "Harold Weiss" <hweiss-at-new.rr-dot-com> 

Hi Ian,

It's 50A 120V per leg.  Preferably a Wye or a star connected system. It
should have a 5 wire output. (phase A,B,C, neut,gnd)  I ran into this
problem on Frankenstien this fall.  Using a 30A 240V 4wire outlet, I would
get 208V.  As my controller has two 120V legs with a common neutral. (main
variac on one, phase controller and control voltage on the other.)  I would
see 120V on each leg only the legs are out of phase.  My 6" uses a
hysterisis type sync motor.  It was murder to try to get the rotory to sync.
And it wouldn't do it on cue!  The phase controller helped but not enough.
The main failure I had was getting into the stage lighting system and
messing things up. Luckily no damage there.  My system would best be run on
a 240V single phase line.  I would like to build a phase comparator that
would show where the peak on the AC line is in comparason to the points on
the SRSG. That way I could sync up before I turned on the HV to the coil.
Still working on that circuit.

David E Weiss

 > Original poster: "Ian McLean" <ianmm-at-optusnet-dot-com.au>
 >
 > Hi all,
 >
 > I have been talking to my electrician about getting a 50A feed into my
 > workshop.
 > He has informed me that this is usually done with a 3-phase connection.  I
 > should have pressed him for some more questions, but forgot, so I'll ask
the
 > knowledgeable people on this list.
 >
 > My knowledge of 3-phase power is sketchy, whilst I do understand the
basics.
 >
 > If the outlet is rated at 50A 3-ph, then how much power is available per
 > phase (to neutral) ?
 >
 > If it is 1/3 of 50A that is OK, I could split the power - use one phase
for
 > the HV supply, and another for the RSG - but this raises a major issue.
The
 > RSG will be out of phase with the HV supply by 120 or 240 degrees
depending
 > on which two phases I use.  Is there any way of adjusting this with some
 > sort of phase angle adjustment.  The JF phase adjuster can only manage
about
 > 90 degrees or so I believe.
 >
 > I wonder how my NST's would cope if I connected them between phases ?
This
 > way they would be getting 415VAC, not 240VAC - and I wonder if the
 > insulation in the tranformers could cope with the higher voltage.  Anyone
 > tried this ?  My guess is .. no way .. we would be upping a 15kV
tranformer
 > to nearly 30kV, and we all know this is about the dialectric strength of
 > air, and the first real problem point for insulation breakdown and corona.
 >
 > Rgs
 > Ian
 >
 >
 >