Trouble Shooting Receptacle

[ptonsparky]

I guess I'l ask the question with the obvious answer. The two breakers are same phase, yes? From what I read above, they would have to be. But I gotta ask. I'm not looking for an answer of "Well, they must be same phase". I"m looking for an answer of "I looked in the panel, and YES, they are same phase".

Maybe I need more coffee. I thought I knew the answer to the problem but now I’m not sure I have the correct question for the answer.:blink:

 

[Adamjamma]

Well, if they take two breakers to shut down, are the breakers side by side? that should tell you something. The labels? Do they give you an idea on where to look? I am betting that it is a case of a switch and a light in a box as well... and the lighting and the outlet in question are both on same phase and require both breakers to cut off... Be kinda interesting to figure out..lol.

Not sure but wouldnt resistance tests help pinpoint the crossed area?

 

[ptonsparky]

Well, if they take two breakers to shut down, are the breakers side by side? that should tell you something. The labels? Do they give you an idea on where to look? I am betting that it is a case of a switch and a light in a box as well... and the lighting and the outlet in question are both on same phase and require both breakers to cut off... Be kinda interesting to figure out..lol.

Not sure but wouldnt resistance tests help pinpoint the crossed area?

Resistance tests? Only if you can look at a spiders web and determine where to put the probes and even then that’s cheating because you can see the whole thing.

 

[Sparky1981]

I guess I'l ask the question with the obvious answer. The two breakers are same phase, yes? From what I read above, they would have to be. But I gotta ask. I'm not looking for an answer of "Well, they must be same phase". I"m looking for an answer of "I looked in the panel, and YES, they are same phase".

Yes they are both on the B phase leg.

 

[Sparky1981]

I am going to have my brother pull all the boxes that are tied into these two circuits and see if he can find a splice in one of these boxes tying these two circuits together. Hopefully its that easy.

 

[growler]

There is no way to know exactly where it is but you can get some information by shutting off the breakers one at a time and determining what is on that circuit.

With either breaker on, there will be 120 volts from one breaker terminal to the other. Both breakers will have to be off to see what the circuit powers.

Marky the Sparky you are right. Bit of a brain freeze we are not used to cold weather in this part of the country.

Odds are that the hots are the only conductors that are connected. He could remove the neutral to one of the cables and see if this separates the circuits.


This would let him know the the circuits do power lights in different sections of the house. The most common place for someone to combine circuits is in a switch junction box. They do it by mistake thinking all the feeds can go under one wire nut when changing out switches.

 

[LarryFine]

It could also be a simple case where someone accidentally ran two home runs when the house was built.

 

[Adamjamma]

Resistance tests? Only if you can look at a spiders web and determine where to put the probes and even then that’s cheating because you can see the whole thing.

Well, if I knew which two breakers are required to be turned off for the outlet to not have power, I would then pull those two breakers... by connecting from one wire to the other wire with my meter and checking resistance against the normal resistance of the wire, I would have an idea of the distance the two wires are connected as one circuit... then by checking using a trailing wire or extension cord to do resistance tests from the outlet in question, I can start determining where the actual cross wire is... all because I have my onsite guide and my dewalt guide to give me the resistance characteristics of the wire, and hopefully the wire is an identical wire...lol..
of course, training here in London makes that sort of stuff kind of a required training for ring circuits and finding where such circuits are broken or misfired.... but... pretty sure any of you trained electricians could do it faster and better than a mere trainee

 

[K8MHZ]

The first thing I would look for is a receptacle that used to be switched, but no longer is. Old switched and non switched circuits may have got tied together during a receptacle swap or something of the sort.

For lots of people, if they connect like colors to like and it works, they did good. That could happen anywhere and tie the two circuits together.

 

[Fmkehoe]

I’ve seen outlets with the tab between the screws clipped and run as two separate circuits.

 

[JPinVA]

If you can identify the neutral associated with each circuit in the panel, you might gain insight by disconnecting the neutral for each circuit and see how that affects power at the outlets. Might give some insight on which outlets to pull for a looksee.

 

[K8MHZ]

If you can identify the neutral associated with each circuit in the panel, you might gain insight by disconnecting the neutral for each circuit and see how that affects power at the outlets. Might give some insight on which outlets to pull for a looksee.

:thumbsup:

 

[MAC702]

I’ve seen outlets with the tab between the screws clipped and run as two separate circuits.

Most commonly this will be done as a MWBC to share the neutral and use a common cable with two hots. But then, they are also supposed to be from opposite buses so would make a dead short when the tab isn't clipped.

But yes, one could certainly clip the tab between the silver screws and run two independent circuits on two independent cables from the same bus. Code does [now] require this to be handle-tied as on the same yoke, though, so not likely to be seen again.

When from the same bus, it will usually be on the same circuit, as part of a switched "half-hot."

 

[JFletcher]

The first thing I would look for is a receptacle that used to be switched, but no longer is. Old switched and non switched circuits may have got tied together during a receptacle swap or something of the sort.

Excellent point. I'd forgotten about that. if someone has gone from switched to unswitched, it's usually done one of two ways... First being just tying together the switched leg and the permanent hot in the switch box... if they have come from two different breakers, this is likely the only interconnection point between the two circuits.

the second way is replacing all the receptacles with ones without a broken tab, and capping off the switch leg in the switch box.

Both of these possibilities will be found in a two gang or larger switch box, which is another reason why it is a good starting point to find crossed up/double/backfed ungrounded conductors.

 

[Barbqranch]

If it is from replacing a switched outlet with an unswitched duplex outlet, there should be a switch somewhere that now doesn't do anything. Homeowner may know where.

 

[K8MHZ]

If it is from replacing a switched outlet with an unswitched duplex outlet, there should be a switch somewhere that now doesn't do anything. Homeowner may know where.

:thumbsup::thumbsup:

If not, make sure you look behind curtains and shelves!

 

[LarryFine]

It would be funny if a seldom-used switch was the inter-connection.

 

[kwired]

I use 20 amp in kitchens and garages because I have seen a few 15 amp outlets melt..usually when running a blender or a big toaster or a big drill on an extension cord, but...
Of course, that was the old style outlets and not the new tr or decora style outlets. Someone told me they have never seen a 15 amp outlet melt that was properly torqued and another told me he saw one handle 28 amps so he did not think I needed to worry about it.
But, If we can just put 15 amp outlets on 20 amp circuits and not worry about it, why can we not put fifty amp outlets or 45 amp even on 60 amp circuits? I mean, the outlet should hold up just fine, but yet we yell about it. Yet 15 amp on 20 amp circuits, even on 20 amp dedicated circuits, is ok. Perhaps we just need the manufacturers to stop making the 15 amp and make them all 20?

Big difference is between "standard grade" and "specification grade" Those cheap $1 or less (maybe only $.50 for non tamper resistant) and a $2 or $3 receptacle is quality of the contact surfaces where the cord cap mates up with. The cheap ones are lesser quality and don't hold with as great of contact pressure over time as the more expensive ones. I've never seen a cheap grade 20 amp receptacle, but though they are spec grade they also usually are at least 10-20% higher cost than 15 amp spec grade.

The easiest way to remedy this is to determinate breaker 3.

Cap and label the conductor: "Warning, fed from breaker 1".

Label breaker 3: "Spare"

Most of the time 1 and 3 have 240 volts between them.

It could also be a simple case where someone accidentally ran two home runs when the house was built.

or accidentally put a cable between two outlets that were intended to be on separate circuits, or similar type of thing.

 

[romex jockey]

eventually, one will find an OCPD off w/120V

~RJ~