Electrical troubleshooting question

[BgBmBoo]

The problem will be fixed soon but I am curious as to the root cause. I have been experiencing a situation where I lose power to a circuit but the breaker doesn't trip. I have isolated the circuit. Manually tripping the breaker will restore power. Manually tripping the main breaker will also restore power so it makes me think the individual circuit breaker isn't tripping and not indicating tripped. When this happens the circuit is nowhere near overloaded. What causes a breaker to do this? Faulty breaker?

The breaker in question is located in an old FPE panel. Yeah I know... I've been pulling wire all winter in preparation to replace and consolidate two panels in my home into one nice new Eaton CH. Should happen in the next month so the issue will be resolved soon, I'm just curious as to how this happens.

Thanks in advance for any information.

 

[kaffine]

What is on the circuit and how are you determining loss of power?

 

[dogdog]

try swaping another known good circuit breaker over and see if the symptom is with the breaker / wiring?

 

[wyliesdiesels]

Well your first problem is the FPE. All bets are off.

Is the breaker a GFCI?

As others have said, how do you know youre losing power? How do you know the circuit isnt overloaded?

If resetting the main breaker but not the branch breaker fixes it, sounds like its not the branch breaker.

 

[BgBmBoo]

What is on the circuit and how are you determining loss of power?

The circuit is one of the original house light/outlet circuits and so far that's I'll I've found on this circuit.

try swaping another known good circuit breaker over and see if the symptom is with the breaker / wiring?

That's a good idea!

Well your first problem is the FPE. All bets are off.

Is the breaker a GFCI?

As others have said, how do you know youre losing power? How do you know the circuit isnt overloaded?

Nope, not a GFCI. Oddly enough, this problem only happens at night (that I have observed) and I happen to be putting the kiddo to bed. The baby monitor light will flicker and the floor fan shuts off (plugged into same outlet). I made the assumption the circuit wasn't overloaded because other than the monitor, fan and one light (60w bulb) there is nothing else turned on anywhere in the house at the time this happens.

If resetting the main breaker but not the branch breaker fixes it, sounds like its not the branch breaker.

This is mainly why I asked. My first thought was bad breaker but once I learned that resetting the main would restore power I started to question that. The fact that it is FPE also made me think it was a breaker problem. That panel has been a thorn in my mind since we moved into this house. I'm pretty excited to finally be getting rid of it soon.

 

[CJ7VFR]

I agree with swapping out the breaker that is giving you trouble with one of the same amp size that is not.

Then you will see if the supposed bad one will have the same issues with some other circuit in the house.

And good luck with the new panel install! Take lots of pictures and post them for us!!

Jim

 

[Phantomd]

Could be a bad socket where the fan and baby monitor are plugged in?

 

[BgBmBoo]

I agree with swapping out the breaker that is giving you trouble with one of the same amp size that is not.

Then you will see if the supposed bad one will have the same issues with some other circuit in the house.

And good luck with the new panel install! Take lots of pictures and post them for us!!

Jim

Thanks! I helped an electrician friend remodel his house a few years ago so I called in a favor and he will help me replace the panel. I've been trying to get as much of the prep work done to make the transition as easy as possible.

Could be a bad socket where the fan and baby monitor are plugged in?

Definitely haven't ruled out that possibility although it probably isn't that particular socket. As we go through each room painting and whatnot I have been replacing all the outlets/switches with commercial grade coopers so it shouldn't be that socket. The only thing remaining upstairs that I haven't touched are a few ceiling lights. It is definitely possible though that there is a hidden outlet or something upstream from that outlet. Found (and eliminated) more than a few of those....

I think one of my main questions was it is possible for a breaker to internally trip or fail and not physically trip the switch? I don't know enough about breaker construction to know if that is even a possibility.

I appreciate the ideas guys, I'll try switching around a couple breakers and see what happens.

 

[Phantomd]

I've absolutely seen a breaker fail in the manner you are describing, I would look there first.

 

[wyliesdiesels]

Yeah especially with FPE breakers.

All bets are off!!