On 10/07/2017 23:41, Terry Coombs wrote:

I noticed up above that the OP says he's got a 220V system ... And a
different layout of main/sub panel breakers than I'm accustomed to . Yes
, I did see Clare's post , and he makes sense . Lot of other info in the
OP's responses , and I haven't a clue what his problem is .

--

Snag

Sorry that I did not explain it clearly. To me, no matter what system it
is, it should always be the sub-breakers that trip first, not the main
breaker. I don't know why one would design a system in which the main
breaker would trip first. It seems to me that design defeats the purpose
of individual breakers. When a sub-breaker is overloaded and the whole
house loses power? That just doesn't make sense to me.

In my case, when a sub-main breaker is tripped (and I'm sure it is not
due to overload. Three refrigerators, a ceiling fan, 10 lights, a water
heater cannot overload a 63A breaker), I can always trace to one single
offending sub-breaker. So, my question is why a sub-main breaker trips
first, not the sub-breaker? The sub-main breaker has a faster response
time than the sub-breaker?