When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.

On 7/9/2017 6:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.



Not necessarily, but I had one main breaker rated at 100 amps that would
trip at about 70 amps. The sub breakers would never trip.

On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.

It sounds like you either have a bad main breaker, a burned up bus
connection or you are running at so close to capacity that one more
thing puts you over without exceeding the capacity of that branch
circuit.
Either buy a clamp on ammeter or pay a sparky to analyse your panel
loading. Sometimes the PoCo will do that for free and call it an
energy audit.

On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.
If you have a full panel - say even 21 breakers - all 15 amp, all
loaded to 80%, you have a 252 amp draw - no branch breakers are
overloaded, yet you are 25% overloaded on a 200 amp main breker.

Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the
main is 100 and you have a bunch of 20A breakers pulling 15A the group
would trip the main.

Note, in case you are possibly unaware of this, that you want to count
on how many amps are being accounted for by CB'ers on each side (or ones
using both sides (poles?) ).


You should do some analysis to see if you are overloading the panel.
If you added Central AC, larger water heater,dryer, electric range,
they may not be a problem individually but together, too much for the
main.

On 10/07/2017 09:31, Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

Thanks for the reply. That's no the problem. I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem. When
the four month raining season comes, some breakers would trip. I don't
know if it is due to moisture or underground short circuit. I flip those
offending breakers and everything is good, except I don't have garden
lights and others which I have yet to figure out what they are. There
are so many breakers in the box. I don't know which one is for what.

Lenny Jacobs wrote:
When it is dry season, there is no breaker problem. When the four
month raining season comes, some breakers would trip. I don't know if
it is due to moisture or underground short circuit. I flip those
offending breakers and everything is good, except I don't have garden
lights and others which I have yet to figure out what they are.

That sounds like a worthwhile project for you. There are tools to help.


There are so many breakers in the box. I don't know which one is for
what.

On 07/09/2017 09:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


One of the best things I ever did was label each circuit on my breaker
panels. As I recall, ~50 circuits took less than a couple hours. Now
get to it!


As far as popping you main breaker, you'll need a meter like this to
solve that mystery:

https://www.amazon.com/Etekcity-MSR-.../dp/B00NWGZ4XC

On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.

That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag

On Monday, July 10, 2017 at 7:29:52 AM UTC-4, Terry Coombs wrote:
On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.

That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag

See Clare's post. If you have a panel full of breakers and most are loaded
near the max, you can be at the main breaker limit. Turn on one more load,
add 5A on a circuit that is already pulling 9A, or even on a circuit
that wasn't drawing anything, and it will trip the main. Someone else
pointed out that if the load is unbalanced, you could also exceed the
max on one leg in a similar way. It;s unusual, but so is his problem.

Another question is if the problem is being caused by the addition of
a normal additional load or a dead short. A dead short can exceed both
the main breaker and the individual circuit breaker at the same time.
Normally just the individual one opens, but it's possible that he has
a fast response time main and a slower response time individual breaker.
I tend to doubt that though, those kind of shorts you'd think you'd
know and they would not be intermittently happening again.
breaker, not the individual circuit breaker.

On Monday, July 10, 2017 at 12:16:44 AM UTC-4, wrote:
On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.
If you have a full panel - say even 21 breakers - all 15 amp, all
loaded to 80%, you have a 252 amp draw - no branch breakers are
overloaded, yet you are 25% overloaded on a 200 amp main breker.

+1

I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem. When
the four month raining season comes, some breakers would trip.

Are these standard breakers or GROUND FAULT INT GFI breakers?

m

On Mon, 10 Jul 2017 07:53:45 -0700, "fake vet Colon Edmund J. Burke"
wrote:

On 7/9/2017 6:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the individual
breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual breakers
with the main breaker on and flip each breaker to see which one causes the trouble.


"Breaker...breaker. This here's da Turd...

No need to tell us, KKKoloon...we KNOW.

--
Illuc nisi Dei gratia vadam.

Tu [sic] es [sic] mulieri [sic] nequam [sic] (KKKoloon's 'Latin' LOL)

On 7/9/2017 10:20 PM, Lenny Jacobs wrote:
On 10/07/2017 09:31, Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

Thanks for the reply. That's no the problem. I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem. When
the four month raining season comes, some breakers would trip. I don't
know if it is due to moisture or underground short circuit. I flip those
offending breakers and everything is good, except I don't have garden
lights and others which I have yet to figure out what they are. There
are so many breakers in the box. I don't know which one is for what.

If moisture is causing such problems, other than as a result of a sump
pump overloading things, then you have real problems that should be
tracked down and fixed ASAP. You don't want your house burning down. If
you can't figure it out quickly, spend the $ on a good electrician.

On 10/07/2017 10:46, wrote:
On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.
If you have a full panel - say even 21 breakers - all 15 amp, all
loaded to 80%, you have a 252 amp draw - no branch breakers are
overloaded, yet you are 25% overloaded on a 200 amp main breker.


Theoretically possible but that's not the case here. Every year, when
the raining season comes and the main breaker is tripped, I can always
trace to the same sub-breakers that cause the problem and turn them
down. They are not tripped all at the same time but they are always the
same four breakers that have the problem.

I studied the breaker box and found that it's not like what I usually
saw in the US. It has a 75 A main breaker labelled Ground-First FL Main
(this is a two-story building). There are two 63 A breakers labelled
Ground FL Main and another two 63 A breakers labelled First FL main.
Looks like this is a three-tier system. It is the same 63A breaker that
is tripped during raining season.

Usually, there are only no more than 10 lights on, two full-height and a
half-height refrigerators constantly on (doesn't mean the compressors
are constantly running), and a ceiling fan, a water heater. That's it.
Seems to me there is absolutely no reason a breaker would trip with a
load like this. That's why I suspect the culprit is moisture or
underground cable getting short circuited due to rain. Now, two breakers
are turned down. During dry season, all breakers are up.

By the way, this is 220 V.

On 10/07/2017 18:03, Terry Coombs wrote:
On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.

That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag


That is what I'd expect but that's not what is happening here.

I have 10 lights on, a water heater on, three refrigerators on, a
ceiling fan on. How can these trip a 63A (220 V) breaker? It must be
short circuit of some sort. But why is a main breaker tripped, instead
of a sub breaker?

On Monday, July 10, 2017 at 12:14:36 PM UTC-4, Lenny Jacobs wrote:
On 10/07/2017 10:46, wrote:
On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.
If you have a full panel - say even 21 breakers - all 15 amp, all
loaded to 80%, you have a 252 amp draw - no branch breakers are
overloaded, yet you are 25% overloaded on a 200 amp main breker.


Theoretically possible but that's not the case here. Every year, when
the raining season comes and the main breaker is tripped, I can always
trace to the same sub-breakers that cause the problem and turn them
down. They are not tripped all at the same time but they are always the
same four breakers that have the problem.


How do you identify which one caused it? Does it immediately trip the
main again when you put the offending breaker on, ie the fault is
still there? If so, if it's not intermittent, I would think you'd
immediately further track down what the source of the fault is.



I studied the breaker box and found that it's not like what I usually
saw in the US. It has a 75 A main breaker labelled Ground-First FL Main
(this is a two-story building). There are two 63 A breakers labelled
Ground FL Main and another two 63 A breakers labelled First FL main.
Looks like this is a three-tier system. It is the same 63A breaker that
is tripped during raining season.

Do you really mean tripping or that it's something on that 63A breaker that
causes the main to trip? You said the main was tripping, not the
other breaker. Also this picture is different than what I think most
of us were envisioning, which was a typical main panel with individual
branch circuits, not a main that feeds what appears to be two subpanels,
That shouldn't really matter though.

What do you believe the total load normal load on it is, just before
it trips? What's going on at the subpanels when this happens,
those 63A breakers must feed subpanels of some kind.
Anything tripped there? As to why the 75A trips first, it makes
more sense now. Breakers have curves as to how fast they trip
versus the size of the fault. Different breakers will have different
curves and they are not exact. What you have is a 63A breaker and
a 75A both exposed to an overload. Additionally, you don't tell us
what else is on that main panel besides the two 63A breakers, but
if there are other circuits, then the 75A is seeing whatever the 63A
one is, plus those other loads. With other loads, no surprise it
trips first. Even without other loads, if you present a major over
load to both, the 75A might trip first if it's curve is slightly
different.

I think most of us were envisioning that you had a big main breaker,
eg 150A and then smaller breakers, eg 20A that feed those other
circuits.





Usually, there are only no more than 10 lights on, two full-height and a
half-height refrigerators constantly on (doesn't mean the compressors
are constantly running), and a ceiling fan, a water heater. That's it.
Seems to me there is absolutely no reason a breaker would trip with a
load like this. That's why I suspect the culprit is moisture or
underground cable getting short circuited due to rain. Now, two breakers
are turned down. During dry season, all breakers are up.

By the way, this is 220 V.

Where are you? We were assuming this is US.

On Mon, 10 Jul 2017 11:50:12 +0630, Lenny Jacobs
wrote:

On 10/07/2017 09:31, Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

Thanks for the reply. That's no the problem. I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem. When
the four month raining season comes, some breakers would trip. I don't
know if it is due to moisture or underground short circuit. I flip those
offending breakers and everything is good, except I don't have garden
lights and others which I have yet to figure out what they are. There
are so many breakers in the box. I don't know which one is for what.
Get busy and map the breakers!!!!

On 7/10/2017 8:50 AM, trader_4 wrote:
On Monday, July 10, 2017 at 7:29:52 AM UTC-4, Terry Coombs wrote:
On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.
That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag
See Clare's post. If you have a panel full of breakers and most are loaded
near the max, you can be at the main breaker limit. Turn on one more load,
add 5A on a circuit that is already pulling 9A, or even on a circuit
that wasn't drawing anything, and it will trip the main. Someone else
pointed out that if the load is unbalanced, you could also exceed the
max on one leg in a similar way. It;s unusual, but so is his problem.

Another question is if the problem is being caused by the addition of
a normal additional load or a dead short. A dead short can exceed both
the main breaker and the individual circuit breaker at the same time.
Normally just the individual one opens, but it's possible that he has
a fast response time main and a slower response time individual breaker.
I tend to doubt that though, those kind of shorts you'd think you'd
know and they would not be intermittently happening again.
breaker, not the individual circuit breaker.

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

On 7/10/2017 11:24 AM, Lenny Jacobs wrote:
On 10/07/2017 18:03, Terry Coombs wrote:
On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.

That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag


That is what I'd expect but that's not what is happening here.

I have 10 lights on, a water heater on, three refrigerators on, a
ceiling fan on. How can these trip a 63A (220 V) breaker? It must be
short circuit of some sort. But why is a main breaker tripped, instead
of a sub breaker?

Where are you ? I haven't a clue what your problem is , from your
responses above you have a totally different setup from what I have
here - 110/220 single phase from a grounded center tap transformer .

--

Snag

On Mon, 10 Jul 2017 22:44:27 +0630, Lenny Jacobs
wrote:

On 10/07/2017 10:46, wrote:
On Mon, 10 Jul 2017 07:58:16 +0630, Lenny Jacobs
wrote:

When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which one
causes the trouble.
If you have a full panel - say even 21 breakers - all 15 amp, all
loaded to 80%, you have a 252 amp draw - no branch breakers are
overloaded, yet you are 25% overloaded on a 200 amp main breker.


Theoretically possible but that's not the case here. Every year, when
the raining season comes and the main breaker is tripped, I can always
trace to the same sub-breakers that cause the problem and turn them
down. They are not tripped all at the same time but they are always the
same four breakers that have the problem.
Then replace the damned things, they are not doing their job. There
is NO WAY the main should kick before the branch circuit protection

I studied the breaker box and found that it's not like what I usually
saw in the US. It has a 75 A main breaker labelled Ground-First FL Main
(this is a two-story building). There are two 63 A breakers labelled
Ground FL Main and another two 63 A breakers labelled First FL main.
Looks like this is a three-tier system. It is the same 63A breaker that
is tripped during raining season.

Usually, there are only no more than 10 lights on, two full-height and a
half-height refrigerators constantly on (doesn't mean the compressors
are constantly running), and a ceiling fan, a water heater. That's it.
Seems to me there is absolutely no reason a breaker would trip with a
load like this. That's why I suspect the culprit is moisture or
underground cable getting short circuited due to rain. Now, two breakers
are turned down. During dry season, all breakers are up.

By the way, this is 220 V.


OK - Euro system. Different problems. No "load balance" issues. 2
"main breakers" in the building. One never trips. The other trips when
it is wet outside. You have external lighting circuits on that main.
You most likely have leakage in those 2 circuits, not enough to trip
the branch breakers, but enough to load the main heavily enough that
the rest of the loads, combined with the circuit leakage, overloads
the main. Find out what is on the circuits in question and get those
circuits checked and fixed - or permanently disconnected.

On Mon, 10 Jul 2017 22:54:12 +0630, Lenny Jacobs
wrote:

On 10/07/2017 18:03, Terry Coombs wrote:
On 7/9/2017 8:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.

That ain't supposed to happen . When an individual circuit overloads
that breaker and only that breaker is supposed to trip . Either you have
a defective main or the wrong amp rating . Or maybe you've got way too
big breakers on the individual circuits . Most mains are 100 or 200 amps
, 30 or 40 amp breakers for stoves/water heaters/dryers , 20 amp for
most outlet circuits and 15's for lighting .

--

Snag


That is what I'd expect but that's not what is happening here.

I have 10 lights on, a water heater on, three refrigerators on, a
ceiling fan on. How can these trip a 63A (220 V) breaker? It must be
short circuit of some sort. But why is a main breaker tripped, instead
of a sub breaker?

Because it is an RCD. (30ma GFCI for you Americans)
Fix your water infiltration problem on the outside circuit.

On Monday, July 10, 2017 at 1:18:30 PM UTC-4, wrote:
OK - Euro system. Different problems. No "load balance" issues. 2
"main breakers" in the building. One never trips. The other trips when
it is wet outside. You have external lighting circuits on that main.
You most likely have leakage in those 2 circuits, not enough to trip
the branch breakers, but enough to load the main heavily enough that
the rest of the loads, combined with the circuit leakage, overloads
the main. Find out what is on the circuits in question and get those
circuits checked and fixed - or permanently disconnected.

This.

But just for completeness, breakers go open for three reasons that I know of, probably more.

You turn them off. They can stand a lot of this. Some are rated to be used this way, but even nonrated ones can do a lot of cycles.

They overload slightly. They can do a lot of these cycles too, but not nearly as many before getting too sensitive or failing. I think it's a factor of 10.

They see a dead short. This is bad. They're only rated to do that twice, and sometimes once is enough. That's okay, they did the job and kept your house from burning down, but now you need a new one.

Rainy weather is probably an overload rather than a dead short. Who knows?

On Mon, 10 Jul 2017 13:20:22 -0700 (PDT), TimR
wrote:

On Monday, July 10, 2017 at 1:18:30 PM UTC-4, wrote:
OK - Euro system. Different problems. No "load balance" issues. 2
"main breakers" in the building. One never trips. The other trips when
it is wet outside. You have external lighting circuits on that main.
You most likely have leakage in those 2 circuits, not enough to trip
the branch breakers, but enough to load the main heavily enough that
the rest of the loads, combined with the circuit leakage, overloads
the main. Find out what is on the circuits in question and get those
circuits checked and fixed - or permanently disconnected.

This.

But just for completeness, breakers go open for three reasons that I know of, probably more.

You turn them off. They can stand a lot of this. Some are rated to be used this way, but even nonrated ones can do a lot of cycles.

They overload slightly. They can do a lot of these cycles too, but not nearly as many before getting too sensitive or failing. I think it's a factor of 10.

They see a dead short. This is bad. They're only rated to do that twice, and sometimes once is enough. That's okay, they did the job and kept your house from burning down, but now you need a new one.

Rainy weather is probably an overload rather than a dead short. Who knows?
Fine line between a heavy overload and a dead short.
If the main is tripping and the branch is not, you can be pretty sure
it is NOT a dead short on one of the branch circuits - - - -

On 10/07/2017 22:10, Bob F wrote:
On 7/9/2017 10:20 PM, Lenny Jacobs wrote:
On 10/07/2017 09:31, Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

Thanks for the reply. That's no the problem. I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem.
When the four month raining season comes, some breakers would trip. I
don't know if it is due to moisture or underground short circuit. I
flip those offending breakers and everything is good, except I don't
have garden lights and others which I have yet to figure out what they
are. There are so many breakers in the box. I don't know which one is
for what.

If moisture is causing such problems, other than as a result of a sump
pump overloading things, then you have real problems that should be
tracked down and fixed ASAP. You don't want your house burning down. If
you can't figure it out quickly, spend the $ on a good electrician.

I did ask an electrician about the breaker tripping problem. He said
casually that's due to moisture. No need to fix. Just live with it.
Since those breakers don't seem to control anything important (the only
thing I notice is garden lights not working), I just live with the problem.

On Tue, 11 Jul 2017 07:00:20 +0630, Lenny Jacobs
wrote:

On 10/07/2017 22:10, Bob F wrote:
On 7/9/2017 10:20 PM, Lenny Jacobs wrote:
On 10/07/2017 09:31, Ed Pawlowski wrote:
On 7/9/2017 9:28 PM, Lenny Jacobs wrote:
When a breaker is tripped, it's always the main breaker, not the
individual breaker. Shouldn't the individual breaker be tripped first?

This is troublesome because I then have to turn off all individual
breakers with the main breaker on and flip each breaker to see which
one causes the trouble.


What is the rating of the main breaker? What is the load? if the main
is 100 and you have a bunch of 20A breakers pulling 15A the group would
trip the main.

You should do some analysis to see if you are overloading the panel. If
you added Central AC, larger water heater,dryer, electric range, they
may not be a problem individually but together, too much for the main.

Thanks for the reply. That's no the problem. I can always trace the
problem to one single breaker and flip it. That solves the problem for
quite a while. When it is dry season, there is no breaker problem.
When the four month raining season comes, some breakers would trip. I
don't know if it is due to moisture or underground short circuit. I
flip those offending breakers and everything is good, except I don't
have garden lights and others which I have yet to figure out what they
are. There are so many breakers in the box. I don't know which one is
for what.

If moisture is causing such problems, other than as a result of a sump
pump overloading things, then you have real problems that should be
tracked down and fixed ASAP. You don't want your house burning down. If
you can't figure it out quickly, spend the $ on a good electrician.

I did ask an electrician about the breaker tripping problem. He said
casually that's due to moisture. No need to fix. Just live with it.
Since those breakers don't seem to control anything important (the only
thing I notice is garden lights not working), I just live with the problem.
There is a safety issue - disconnect the circuits from the breakers
and rest easy.

On 10/07/2017 23:48, wrote:


OK - Euro system. Different problems. No "load balance" issues. 2
"main breakers" in the building. One never trips. The other trips when
it is wet outside. You have external lighting circuits on that main.
You most likely have leakage in those 2 circuits, not enough to trip
the branch breakers, but enough to load the main heavily enough that
the rest of the loads, combined with the circuit leakage, overloads
the main. Find out what is on the circuits in question and get those
circuits checked and fixed - or permanently disconnected.


I flipped the offending breakers to turn them off until dry season
comes. Then, I turn them on. The only difference I notice is the garden
lights.

On 10/07/2017 23:01, trader_4 wrote:
On Monday, July 10, 2017 at 12:14:36 PM UTC-4, Lenny Jacobs wrote:

Theoretically possible but that's not the case here. Every year, when
the raining season comes and the main breaker is tripped, I can always
trace to the same sub-breakers that cause the problem and turn them
down. They are not tripped all at the same time but they are always the
same four breakers that have the problem.


How do you identify which one caused it? Does it immediately trip the
main again when you put the offending breaker on, ie the fault is
still there? If so, if it's not intermittent, I would think you'd
immediately further track down what the source of the fault is.


I flipped all sub breakers down and flipped them one by one to locate
the offending breaker. Once I found the offending breaker, I left it
down and everything would be fine. Well, except that particular circuit
that was turned off.



I studied the breaker box and found that it's not like what I usually
saw in the US. It has a 75 A main breaker labelled Ground-First FL Main
(this is a two-story building). There are two 63 A breakers labelled
Ground FL Main and another two 63 A breakers labelled First FL main.
Looks like this is a three-tier system. It is the same 63A breaker that
is tripped during raining season.

Do you really mean tripping or that it's something on that 63A breaker that
causes the main to trip? You said the main was tripping, not the
other breaker. Also this picture is different than what I think most
of us were envisioning, which was a typical main panel with individual
branch circuits, not a main that feeds what appears to be two subpanels,
That shouldn't really matter though.


Sorry for the confusion. I had not known the system was this complex
before I checked it. There are two panes. One contains a main 75A
breaker with four 63 A sub-main breakers. Before, I had been saying
"main breaker". It turned out to be a 63A sub-main breaker.

There is another panel containing about 50 breakers (actually, this
panel has two chambers, one containing 50 or so breakers, the other
empty). There are no more panels.

What do you believe the total load normal load on it is, just before
it trips? What's going on at the subpanels when this happens,
those 63A breakers must feed subpanels of some kind.
Anything tripped there? As to why the 75A trips first, it makes
more sense now. Breakers have curves as to how fast they trip
versus the size of the fault. Different breakers will have different
curves and they are not exact. What you have is a 63A breaker and
a 75A both exposed to an overload. Additionally, you don't tell us
what else is on that main panel besides the two 63A breakers, but
if there are other circuits, then the 75A is seeing whatever the 63A
one is, plus those other loads. With other loads, no surprise it
trips first. Even without other loads, if you present a major over
load to both, the 75A might trip first if it's curve is slightly
different.

I would think main breakers would have a slightly longer response time
so to give time to sub breakers to trip.


Where are you? We were assuming this is US.

Thailand.

On 11/07/2017 07:12, wrote:

There is a safety issue - disconnect the circuits from the breakers
and rest easy.

Is this the same as flipping the breaker to turn of the circuit?

On 7/10/2017 8:30 PM, Lenny Jacobs wrote:


I did ask an electrician about the breaker tripping problem. He said
casually that's due to moisture. No need to fix. Just live with it.
Since those breakers don't seem to control anything important (the only
thing I notice is garden lights not working), I just live with the problem.

You may have just pinpointed the problem. Outdoor wiring and fixtures
are exposed to the elements and there may be a bad connection someplace.
Moisture from rain or condensation may be just enough to make a short.

On Tue, 11 Jul 2017 07:48:39 +0630, Lenny Jacobs
wrote:

On 11/07/2017 07:12, wrote:

There is a safety issue - disconnect the circuits from the breakers
and rest easy.

Is this the same as flipping the breaker to turn of the circuit?

If you are really in Europe, that is an RCD and is tripping because of
a ground fault, not an overload. You have to fix the water intrusion
problem. Once you isolate the bad circuit, open the outside boxes and
figure out which one has water in it.

On 7/10/2017 9:18 PM, Lenny Jacobs wrote:
On 11/07/2017 07:12, wrote:

There is a safety issue - disconnect the circuits from the breakers
and rest easy.

Is this the same as flipping the breaker to turn of the circuit?

Removing the wire from the breaker. No more power to the line.

On 11/07/2017 03:47, wrote:
Fine line between a heavy overload and a dead short.
If the main is tripping and the branch is not, you can be pretty sure
it is NOT a dead short on one of the branch circuits - - - -

Good assumption. But in my case, when I turned off all breakers and
flipped them one by one to locate the offending breaker, I always found
one breaker (different ones on different occasions, a total of four
breakers) that, when flipped, would trip the sub-main breaker.

Also, as I stated in another post, I have a total of 10 lights, three
refrigerators, a water heater, and some small gadgets such as TV, DVD
player, etc. There is no way they would overload a 63A, 220 V breaker.

On 11/07/2017 00:55, wrote:


Because it is an RCD. (30ma GFCI for you Americans)
Fix your water infiltration problem on the outside circuit.


No. They are regular breakers. GFCI breakers have a test button. Mine don't.

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?

On Tue, 11 Jul 2017 07:48:39 +0630, Lenny Jacobs
wrote:

On 11/07/2017 07:12, wrote:

There is a safety issue - disconnect the circuits from the breakers
and rest easy.

Is this the same as flipping the breaker to turn of the circuit?
No - pull the wires so they CAN NOT be energized. There is a safety
fault on those circuits - don't take a chance on killing someone.

On Tue, 11 Jul 2017 08:08:19 +0630, Lenny Jacobs
wrote:

On 11/07/2017 03:47, wrote:
Fine line between a heavy overload and a dead short.
If the main is tripping and the branch is not, you can be pretty sure
it is NOT a dead short on one of the branch circuits - - - -

Good assumption. But in my case, when I turned off all breakers and
flipped them one by one to locate the offending breaker, I always found
one breaker (different ones on different occasions, a total of four
breakers) that, when flipped, would trip the sub-main breaker.

Also, as I stated in another post, I have a total of 10 lights, three
refrigerators, a water heater, and some small gadgets such as TV, DVD
player, etc. There is no way they would overload a 63A, 220 V breaker.
What is the rating of the branch circuit breakers?

On Tue, 11 Jul 2017 08:09:58 +0630, Lenny Jacobs
wrote:

On 11/07/2017 00:55, wrote:


Because it is an RCD. (30ma GFCI for you Americans)
Fix your water infiltration problem on the outside circuit.


No. They are regular breakers. GFCI breakers have a test button. Mine don't.

Are you sure your main is not an RCD? Is there a reset button? (The
RCDs I have seen don't have a test button) You say 63a and that
immediately says this is not the US because we do not have 63a
breakers here. I thought most countries with 220v used RCDs.

New Zealand
http://gfretwell.com/ftp/New%20Zeala...i/Breakers.jpg

On Monday, July 10, 2017 at 9:38:25 PM UTC-4, Lenny Jacobs wrote:
On 11/07/2017 03:47, wrote:
Fine line between a heavy overload and a dead short.
If the main is tripping and the branch is not, you can be pretty sure
it is NOT a dead short on one of the branch circuits - - - -

Good assumption. But in my case, when I turned off all breakers and
flipped them one by one to locate the offending breaker, I always found
one breaker (different ones on different occasions, a total of four
breakers) that, when flipped, would trip the sub-main breaker.

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.



Also, as I stated in another post, I have a total of 10 lights, three
refrigerators, a water heater, and some small gadgets such as TV, DVD
player, etc. There is no way they would overload a 63A, 220 V breaker.