Re: Inductive Kick LTR Pig Systems

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 8/28/00 12:21:56 AM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:

> 
>  My understanding of PF correction is to bring the system to unity, 
> ultimately
>  using PFC's to create a net reactance of zero (Xl = Xc) where reactive 
power 
> =
>  real power. Assuming a pig used PFC's that actually brought the PF to very 
> near
>  1, how would we limit current? Purely resistive methods? Maybe this 
explains
>  why pigs use inductive current limiting? Not sure, just thinking here. 

Bart,

Often we don't want to limit the current during cap charging, only
during gap firing.  During charging, the Xc and Xl cancel, but the
system goes fully inductive (current limited) during gap firing, so
we don't get power arcs.  The ballast automatically provides this feature.
Those who get thumping in the inductors may add resistance to
limit the current somewhat during charging.  Yes, with this
adjustment, resistive limiting is basically the only limiting
during charging.

John Freau