On Friday, July 24, 2015 at 6:18:05 PM UTC-4, trader_4 wrote:
....snip...

If the breaker trips when you push the test button, it's working.

....snip...

This is something I like to toss out every couple of years just for fun and to
be a PITA. ;-)

The statement above is not entirely correct. In reality, it should read:

"If the breaker trips when you push the test button, it worked."

As soon as we reset the breaker, we have no idea of it's working or not. If
we test it again 2 seconds later, then we know that it *was* working, but we
still don't know if it *is* working after we reset it. The only thing we know
for sure is that it worked when we pressed the button. That in no way ensures
that it will work when we actually need it to.

Why do they suggest that we test our GFCI's once a month? Is it to make sure
that they will trip when a hazard exists? Not really. The best we are able to
determine is that the GFCI would *not* have tripped if a hazard existed. If it
doesn't trip when the test button is pressed, odds are it wouldn't have tripped
if a hazard occurred. However, the fact that it does trip when the button is
pressed does not guarantee that it won't fail between that test and the hazard.

If they never failed while just sitting there, why would we even need to test
them? We test them to see if they have already failed, not to see if they will
work when we need them to.