On 12/7/2010 10:05 AM, Nova wrote:

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should trip
together. I know my local code requires it and I think it's specified by
the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html


Then what's keeping all of the "live neutrals" from any of the other
circuits in the panel from raising their evil heads at any time? -- The
Ground (!), right? So, IF the former circuits are well-grounded, then
it seems the "Edison's Circuit" issue will not be a problem. Of
course, that's a crucial, "IF". Correct???

Regards,
Bill