On Tue, 11 Jul 2017 18:51:13 -0700 (PDT), DerbyDad03
wrote:

On Tuesday, July 11, 2017 at 11:35:25 AM UTC-4, wrote:
On Tue, 11 Jul 2017 03:56:18 -0700 (PDT), DerbyDad03
wrote:

On Tuesday, July 11, 2017 at 2:09:00 AM UTC-4, wrote:
On Tue, 11 Jul 2017 10:50:24 +0630, Lenny Jacobs
wrote:

On 11/07/2017 09:38, DerbyDad03 wrote:

In an earlier post you said that the only difference you see when the
offending breaker is off are the garden lights. Now you say that it
it is "different ones on different occasions, a total of four breakers".

Does that mean that you have 4 breakers for the garden lights and that
any (and only) one of them might be the offending one at any given time?
10 lights on 4 different circuits and the problems move from circuit to
circuit?

If so, then that means that only 1 of the 4 circuits is getting wet at
a time, which is really strange. It also means that all 4 circuits have
some type of moisture issue, which is also kind of strange - unless the
fixtures are crappy and/or the person who did the original wiring screwed
up all 4 circuits.

Since garden lights are not working, one of the four must be responsible
for them. I have no clue what the other three breakers are for.

Since you seem to have isolated it to moisture problems in your garden
lights, I would see if you can see where the water is getting in and
seal them up.

I no longer think that's the case. Now he says that only 1 of the 4 possible
breakers that needs to be left off is for the garden lights. He doesn't
know what the other 3 are for. That tells me that when any 1 of the other 3
breakers are left off, something(s) isn't working, but he has no idea what.

Seems to me that he might as well just leave those other 3 breakers off all of
the time since they apparently have no impact on his life. *Then* he can fix
the garden lights and never have a problem again.

Did he really say that he has over 50 breakers and no real clue what
any of them (other than the garden light one) do? Holy crap.



He also says it happens when it rains.
One thing I learned as an inspector is when a guy makes a mistake
installing stuff, he does it a lot. With 50 circuits, there is a real
good chance 4 of them feed wet location loads.
I have a typical US service and I have at least half dozen circuits
with an outdoor load.


I agree except that it's pretty strange that he says that it can be any
1 of 4 circuits that cause the main to trip, yet he only sees one that
makes a difference - the one for the lights. Whatever "load" is getting
wet on the other 3 is not known to him. The only thing I can think of
is receptacles that he doesn't use and perhaps has not located. Testing
them would be pretty easy once he locates them.

It's also strange that - if I understand his explanation correctly - it's
always only *1* of the 4 at any given time. With 4 possible circuits that
can - and apparently do - get wet and cause the problem, why would it always
be just a random 1 of them that causes the problem at any given time? Is the
rain in Thailand selective?
My "suspicion" is any one , or possibly combination of 2, would cause
the problem. Still don't know exactly what amperage the branch
breakers are, but he has a 63 amp "sub-main" that trips. If he has 7.5
amp breakers (equivalent to 15 amp 120 volt) and he has 25 running an
average of 1/4 capacity, that is 46.875 amps. Say the other 4 are at 6
amps each, the main may trip,(70 amps) while shutting any 1 off may
keep it from tripping at 64. The "short" resistance in the 4 may not
be exactly the same - one may draw heavier than the other on a given
day (it IS a "random" fault) - so shutting all 4 off, then turning the
others on, it may be different combinations that work from day to day.