RE: INRUSH SURGE SUPRESION

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>


I've found that inrush current surge suppression was necessary with both
my 15A and 20A Variacs.  They tend to trip the mains breaker when turned
on, but only if they are a short distance from the breaker box.  If they
are distant, the resistance in the wiring is enough of a cushion to
prevent tripping.  I see that Digikey now stocks Ametherm NTC thermistor
surge suppressors, rated up to 50A (catalog page 1328).

Regards, Gary Lau
MA, USA

> Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
>
> I was wondering how important initial inrush suppresion is with a
> large variac? That is a large power resistor, shorted by contacts on
> a contactor shortly after power-up. I'm designing /building my
> controller for mu big TC. The variac is 3 , 30A/520V staco's in
parallel.
>