Re: Cap Start Motor

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

Original poster: DRIEBEN-at-midsouth.rr-dot-com 



----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
Date: Sunday, May 9, 2004 12:31 pm
Subject: Re: Cap Start Motor

 > BTW, I think I got my variac fixed. The coil was good (no shorts
 > betweenturns).  I hooked up 120VAC to the whole coil to
 > demagnitize it and then
 > thru its circuit breaker and I can now power up without the
 > circuit breaker
 > tripping all the time.  My theory is that the core was left
 > magnetized.Does this hold water?
 >
 > Gerry R
 >
 >
 >


Hi Gerry,

I don't see how the soft silicon steel of the core of any transformer,
with its very high permeability, will hold its own permanent magnetism.
Maybe someone else could comment on this? I have noticed that sometimes
when a circuit breaker has been tripped, if you try to immediately re-
set it and turn it back on, it will often trip again when you turn it
back on after reset. Sometimes I have to "play" with it by going thru
several "reset, power-up" cycles, even though the fault has been re-
moved or corrected. Maybe that was the case with your variac? Just a
thought.

David Rieben