Re: Non ballasting a pig?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 10/14/02 5:16:47 PM Pacific Daylight Time, tesla-at-pupman-dot-com
writes:


>
> Hello list,
>    I've been following some posts where ppl are talking about what it 
> takes to ballast a pig and was wondering this...
>
> I recently installed a new breaker box(200amp) in my house in which I 
> reserved a 100amp 240v breaker for my shop.  Is it possible that this 
> would be enough to power my 7.5kva pig without ballasts?  If I still need 
> to, would one 3000w heater element be enough even though it's lossy?  I'm 
> not fortunate enough to have a stick welder, just a wire welder and the 
> water heater element is handy;)
>
> Thanks,
> Gregg Adams



Gregg,

Your 7.5 kva transformer will draw as much current as your wiring and breakers
will allow with no ballast.  Talking way too much current here.  Distribution
transformers must have some ballast in the primary.  We normally use inductive
ballast as it is most efficient.  The inductive ballast will restrict the
current without reducing the input voltage to the transformer (other than
normal reisitive losses in the wire of the ballast).  If you use resistive
ballast only, it will limit the current but will also cause a voltage drop
across the ballast resistor and reduce the primary input voltage to the
transformer.

Ed Sonderman