Mike Rapoport wrote:
: OK this makes sense. I had not considered that the breakers might not trip
: because of the resistance of the wire feeding the bus during the overload.
: I suppose that there is also the tolerances of the breakers to be
: considered. Thanks!

Hi Mike. These breakers that we have have a fairly complex trip curve.
Potter & Brumfield make the majority of breakers, looking at their web site
will probably turn up a document on how the breakers actually work.

In general, a breaker MUST carry about 110% rated without tripping. At 140%
rated current the trip time us usually measured in hours. 200% rated gets
you into minutes before the breaker trips. 500% rated it should trip in
milliseconds.
--
Aaron C.