Circuit breaker keeps tripping

[E. Robinson]

:)

[E. Robinson]

Heh heh ... I'm a (retired) EE.

So that's funny.

BTW, if you know anything about electrical engineers, they typically don't learn anything practical (in school) about home wiring.

It's all about poles and zeros and Kirchoff's law and fourier transforms and delta/Y transformers and Spice simulations and diffusion doping and Maxwell's equations and Coulomb's law and Faraday's Law and Ohm's law, and c=dv/dt and phase diagrams and polar plots, and cascade versus cascode configurations and emitters and gates, etc.

Nothing whatsoever about typical mains wiring.

[Unquestionably Confused]

Perhaps, but then paintedcow knows a great deal about nothing and even when someone attempts to cure his ignorance, he doubles down and says something even more stupid.

Do let us know the final outcome on this. With the additional details you've provided, it seems almost certain to be a circuit breaker that's simply given up the ghost. That said, I think there's usually a reason other than "its time has come" for breakers to give up. Wondering if you've normally got enough of a load on that 15A circuit to heat it up and that that may have caused the failure.

[Stormin Mormon]

I did meet a person like that. The electric light in his cellar wasn't working right. I got to show him how to shut the breaker, and replace a light switch.

[Stormin Mormon]

Truly profound. I mean, like, I can totally relate.

As a couple other folks have mentioned, it's good to have some basic understanding, and then come here for the details. For example, when I asked about adding hot or cold water to my floor model residential humidifier, I got told a lot of things, none of which answered my question. Sigh. Guess I can't win on that one.

You did get some really good answers, including to just pull the breaker out and replace it, they often aren't that expensive. Also swap two black wires, and see if the problem follows the wire or the breaker.

[trader_4]

Ohm's Law and all the rest of the basics don't apply to how to debug what amounts to a fancy switch? Good grief.

[bob_villain]

Isn't *that* what he's saying, and why he is asking questions? Jezus!

[TimR]

Ingenious. Simple and workable.

If the breaker is bad, there can still be something else wrong too. Sometimes breakers wear out, sometimes they go bad for a reason.

[Ralph Mowery]

I can understand that. Just because one knows the theory about things does not mean he will have trouble shooting abilities even on something simple. I doubt the EE degree even mentions home wireing or simple breakers for the house. I went to a 2 year technical college for electronics engineering and did not get into the simple things. Lots of time on theory and none on how to repair things that did not work.

I went to work in a large plant and delt with things as large as 480 volt 3 phaase at 500 amps. Almost nothing in the plant ran on 120 volts except in some offices, so did not get much about the simple things you would find around the house.

[Scott Lurndal]

For advice on the many thousands of things a homeowner is qualified to repair without danger.

Electrical work isn't one of them.

[E. Robinson]

It's fixed.

[E. Robinson]

The best answer was to shut the mains off, and then test the circuit breaker. That is a great test, and it showed the problem.

[E. Robinson]

The tricks that I was asking about, most people here didn't even know themselves.

I'm not blaming anyone for not knowing the tricks, but, just by way of example some folks would have me pull the breaker, to test its operation, but, a SIMPLER way to test it is to just shut the mains first.

Then see if the breaker still trips. That checks, for example, for mechanical problems.

That's the kind of *practical* pragmatic advice I was looking for. Ohms law is just fine and dandy (duh, there was a short), but the question was how best to *find* that short given all the wires are in the walls.

Anyway, it's solved now, thanks to the combined advice here.

[E. Robinson]

Thank you for understanding.

To know the electrical equations that are involved in making a motor spin doesn't mean I know jack shit in practical terms about fixing electrical motors.

Since *all* the wiring was hidden, and since there was obviously a dead short *somewhere*, I was asking for hints on how to find that.

Sure, Ohms law is telling me that the current shoots up when the short causes near-zero impedance, but, heck, that doesn't tell me practically how to test for the short.

BTW, the trick of shutting off the mains and then testing the circuit seems to be a great time saver for testing the breaker itself.

They do *not* teach you that stuff in college.

[E. Robinson]

I'm sure every school is different, but you are correct. Not once do they mention the wiring of the home. So, if you didn't already know that it's 110VAC 60Hz, you're not gonna learn that at school with an EE degree.

Neither do they really cover power transmission.

The sort of hint at it when they cover transformers and when they cover the skin effect and AC impedance, but, not once in the entire college education of a typical EE does he see a circuit breaker.

Yup. I mean, they cover transformers, in all their configurations, and phase shift, and they cover single phase, two phase, three phase power, etc., but not once do they show you a typical power transformer that is on your telephone pole, although they do theoretically cover load balancing.

That's another thing they NEVER cover in electrical engineering! They never tell you that it's roughly 400 volts on the distribution lines and tens of thousands of volts on the transmission lines and they never cover how the ground differs from the neutral in a typical home system.

In fact, as I said, not once in 4 years did they cover anything related to a typical home system. Of course, as someone noted, Ohms law still holds sway, but that simply tells me I have a short.

But FINDING the short was where I needed your help.

[TimR]

Great!

And thanks for getting back to the group.

One common scenario here: the OP writes in with a problem, the group discu sses back and forth, the OP disappears, the thread dies, the thread is resu rrected 10 years later, the argument continues.

Just a comment: the sooner you are sure what is wrong, the more you find i t impossible to see contrary evidence. Troubleshooting is best with an ope n mind. And don't forget there can be a bad breaker AND a short.

I looked up breaker longevity some time ago and don't remember the exact nu mbers, but they were in this neighborhood. A breaker can be turned on and off something like 30,000 times before it wears out. It can trip on mild o verload maybe 1-3000 times. But a dead short drawing full available curren t will kill it in 1 to 2 times.

[Stormin Mormon]

Ah, so you had a loose neutral, then? Or was it some other problem?

[E. Robinson]

That is the kind of a.h.r advice I was looking for!

It worked perfectly!

In fact, your approach worked so perfectly, that it, um, uh, er.... it SOLVED the problem! Huh? What?

The problem is gone? Just like that?

Well, not exactly (it couldn't have solved the problem), but this is what happened!

1. The "bad" breaker was in the off position.
2. Unfortunately, I didn't think to test it today (last tested 2 days ago).
3. I went outside and turned the mains off.
4. I went to the breaker panel, and turned the "bad" breaker on.
5. It stayed in the on position!
6. I flipped it back and forth a few times.
7. It stayed in the on position!
8. I left it in the on position.
9. I went outside, and flipped the mains back on.
10. I had expected the "bad" circuit to trip.
11. Huh? It was still in the on position.
12. I flipped it back and forth a few times.
13. It worked perfectly fine.
14. I went upstairs, and turned each affected light on (one by one).
15. They *all* worked (one multi-bulb light had 1 of 5 bulbs burnt out).
16. Maybe that one bulb caused the circuit to blow? Naaah.

I removed the one bad bulb, but, other than that, nothing (that I know of) has changed between now and two days ago (other than the rain stopped, which has been constant here in California the past few weeks).

I don't understand, but, somehow, that ingenious trick showed not only that the circuit breaker was good, but, that the circuit, somehow, is (at least now) also good.

Makes no sense, I agree. But that's the data. I will let you know if it trips again.

[E. Robinson]

Here's the somewhat hard to fathom explanation I gave in another post.

That is the kind of a.h.r advice I was looking for!

It worked perfectly!

In fact, your approach worked so perfectly, that it, um, uh, er.... it SOLVED the problem!

Well, not exactly (it couldn't have solved the problem), but this is what happened!

1. The "bad" breaker was in the off position.
2. Unfortunately, I didn't think to test it today (last tested 2 days ago).
3. I went outside and turned the mains off.
4. I went to the breaker panel, and turned the "bad" breaker on.
5. It stayed in the on position!
6. I flipped it back and forth a few times.
7. It stayed in the on position!
8. I left it in the on position.
9. I went outside, and flipped the mains back on.
10. I had expected the "bad" circuit to trip.
11. Huh? It was still in the on position.
12. I flipped it back and forth a few times.
13. It worked perfectly fine.
14. I went upstairs, and turned each affected light on (one by one).
15. They *all* worked (one multi-bulb light had 1 of 5 bulbs burnt out).
16. Maybe that one bulb caused the circuit to blow? Naaah.

I removed the one bad bulb, but, other than that, nothing (that I know of) has changed between now and two days ago (other than the rain stopped, which has been constant here in California the past few weeks).

I don't understand, but, somehow, that ingenious trick showed not only that the circuit breaker was good, but, that the circuit, somehow, is (at least now) also good.

Makes no sense, I agree. But that's the data. I will let you know if it trips again.

[DerbyDad03]

exact numbers, but they were in this neighborhood.

...on average.

...on average.

...on average.

You forgot: A breaker could be bad right out of the box or still work after more than 50,000 on-off cycles.