Re: Ok, what is an LTR cap.

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

In a message dated 8/24/00 7:24:40 PM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

<< Original poster: "Mark Broker" <broker-at-uwplatt.edu> 
 >
 > > Actually, PIG's are STR's (smaller than resonant). Typically, coilers 
use a
 >
 > > 10kva, 14.4kv pig's. Resonant caps are 0.128uF (from memory). Obvisouly
 > HUGE! 
 > > We typically use smaller than resonant caps (STR's) on our systems. 
NST's 
 > > however (and OBIT's), can use LTR's. Could you imagine the joules for a 
pig
 >
 > > using an LTR? I see smoke, fire, wooosh!!! Well, for most of us, not 
Greg, 
 > > Bill, Hull, etc... or you Chris (yet?). 
 >
 > Actually, Terry's MMC Calc gives me .351uF.
 
 For a 240/14.4kv, 694mA, 20,749 ohm pig? Terry is .351uF correct? I though a
 matching reosnant cap size should be 0.128uF. Maybe my math is wrong here.
 Someone please clarify? 
  >>
As I found out the hard way, you can also get into a 60 hz resonant condition 
with probabaly any cap by varying the inductance in the primary used as 
ballast.  I am using .05uf with a 14.4  5 kva distribution transformer and it 
was resonant with the particular welder that I was using.  It was an 
uncontrollable condition.  Maybe with a sync rotary gap, but not with my non 
sync rotary.

Ed Sonderman