Contractor Talk - Professional Construction and Remodeling Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #1 ·
We were just sitting here and two circuits blew. One new segregated 20 amp circuit and an unrelated plug circuit that is original to the house.

They are both using used breakers, but I can't imagine they would go out at the exact same time. Only a portable a/c unit and some standby mode stereo gear on the 20 amp. The other circuit only had a phone and a modem on it at the time.

It is an old house, but these two circuits are newer.

Any thoughts. I am stuck using my phone, so it is a pain to make coherent post.
 

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #4 ·
What's a segregated circuit? One where the black and white wire can't be in the same romex?
Hey, I ain't no electrician. I mean that it is on it's own breaker and only goes to one wall in the mancave. The a/c is plugged into a 50 foot extension cord, but it has ran that way with my H/T gear on for a month or so with no problem.

We are hearing what may be a critter in the inner kitchen wall, so maybe he ate two unrelated wires?

I realize it is impossible to diagnose it from a post, but I am not sure where to start. Two new breakers? Physically trace the wires and look for breaks? I'm not too keen on crawling under there with a noisy critter but I will. I'll bring a big stick and a bright light.
 

·
Super Moderator
Joined
·
11,937 Posts
By "blew" do you mean both breakers tripped? Or did these two circuits just stop working at the same time?

If the latter, my guess is that these two circuits are on a shared neutral and it failed. BE CAREFUL with this. You could easily have 240 volts at your fingertips. These 2 circuits could also be on a shared neutral and the circuits were not put on opposite phases and the neutral simply burned up due to overload. If whoever put the circuits in backstabbed the devices without pigtails, one of the springs could have finally loosened up.

There are lots of things this could be, but those are my first guesses without being there. Be careful and good luck.
 

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #8 ·
By "blew" do you mean both breakers tripped? Or did these two circuits just stop working at the same time?

If the latter, my guess is that these two circuits are on a shared neutral and it failed. BE CAREFUL with this. You could easily have 240 volts at your fingertips. These 2 circuits could also be on a shared neutral and the circuits were not put on opposite phases and the neutral simply burned up due to overload. If whoever put the circuits in backstabbed the devices without pigtails, one of the springs could have finally loosened up.

There are lots of things this could be, but those are my first guesses without being there. Be careful and good luck.
They both just stopped working at the same time. The shared neutral may be a good place to start. I have a text in to my electrician, so hopefully he can take a look tomorrow. Sheesh, just when I finally thought I would have some jingle in my pocket for a change.

Heck, I didn't want to go to work tomorrow anyway.
 

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #9 ·

·
Registered
Joined
·
7,076 Posts
... Will it show anything I'd the circuits aren't working.[?]....
It could show open neutral. It might seem like nothing's there, but you could have hot and ground both connected, and still have danger. If you haven't done it already, I'd turn both breakers OFF until/unless they're needed back on for diagnosis.
 

·
Registered
Joined
·
1,214 Posts
that lil cube tester will show if you have an open neutral or hot......from there start opening boxes up and looking for the loose or failed connections.

from there it could be burnt or corroded fingers on the breaker or bar, I see it often
 

·
Super Moderator
Joined
·
11,937 Posts
Maybe a shared lug in the panel that came loose?
More likely an improperly shared neutral that finally burned through, especially with an AC unit sucking power.

Just like 480 Sparky, I tend to stay out of the electrical section because there is so much that can go wrong and I don't want that on my conscience by giving out electrical advice on the internet without an up close personal troubleshooting session IN PERSON.

For proven members though, I'll help out when I can feel comfortable.
 

·
Registered
Joined
·
242 Posts
What I meant was on the same lug on the buss bar. Im not an electrician but in my area there are always shared lugs on the neutral/ground buss's. I have seen the screw loosen on a couple occasions. Or so my electrician:whistling tells me.
 

·
Super Moderator
Joined
·
11,937 Posts
What I meant was on the same lug on the buss bar. Im not an electrician but in my area there are always shared lugs on the neutral/ground buss's. I have seen the screw loosen on a couple occasions. Or so my electrician:whistling tells me.
Yes they do, but the service would have been sporadic in most cases. "Touch and go" if you will.
 

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #19 ·
More likely an improperly shared neutral that finally burned through, especially with an AC unit sucking power.

Just like 480 Sparky, I tend to stay out of the electrical section because there is so much that can go wrong and I don't want that on my conscience by giving out electrical advice on the internet without an up close personal troubleshooting session IN PERSON.

For proven members though, I'll help out when I can feel comfortable.
I definetly appreciate the advice and help. Don't worry though. When it gets into the breaker box, I leave that to the experts. Tomorrow my electrician will get it back up and running.

Then I'll see about getting more than a 60 amp service in there at the same time.
 

·
Registered
Joined
·
12,380 Posts
Discussion Starter · #20 ·
Well it looks like it is a bad connection coming from the power pole.

He came in, flipped the breakers and it worked. He'll resplice and clean up the mess next weekend. Till then we will just keep a light load on those circuits.
 
1 - 20 of 24 Posts
Top