Re: Overrating a Variac

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

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

Tesla list wrote:

> Original poster: "Jason by way of Terry Fritz <twftesla-at-qwest-dot-net>"
><jasonp-at-btinternet-dot-com>
 
> Hi all,
 
> I have a 10A variac and I have a 20A variac bruch

	brush?
	(NOT being sarky, just being sure....)

> that I picked up off a friend. Provided that it physically fits in
> the old variac, does this mean that I will be able to overrate the
> variac by more than usual??

	I wouldn't.
	Current rating of any cored magnetic component is determined
	by a number of things.  Notably, the core must be big
	enough (the mag field has to 'fit inside':  That's a non
	rigorous but apt description.  If not, the core saturates,
	overheats & becomes hot & inefficient.)

	Also, the wire needs to be apt for the current involved.

	Both of those remain unchanged here, even if the brush
	is uprated...  If the brush fits, it can't hurt.

 	best
	dwp