Re: higher current ammeter sources

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

Original poster: FIFTYGUY-at-aol-dot-com 

In a message dated 5/10/04 9:07:44 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:

 >  > I was wondering if there was a source of higher current
 >   > range AC ammeters (like 50 to 100 amps) that didn't require
 >   > an external current transformer for metering?

 >      While transfromers are elegant and efficient, shunts
 >      also work on AC and can be easier to fab.

     Dontcha mean "also work on DC"?
     At my work, our larger (50 HP+) DC motor SCR drives use current shunts in
the armature circuit for current feedback. We also use them for metering and
control by armature current levels. Since these motors take a few hundred
amps, shunts can be pretty handy. Usually marked as to their V drop per A
throughput.
     I would say easy to fab, as they are just calibrated low-value resistors.
Simply a strip of metal on a heavy-duty terminal block. Come to think of it,
they would probably function like fuse links (although I've never seen one
"blow", despite what failed in drive or motor).

-Phil LaBudde