James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
If you connect the black and the red together, you are creating a parallel wiring. I don't believe it's allowed on anything smaller than 1/0
Balanced neutral?
- Thread starter ritelec
- Start date
- Status
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If they're interconnected again downstream, true.
ptonsparky
Tom
- Occupation
- EC - retired
i agree. Only if.
Most likely they are going to different loads along the way, so no parallel.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Jerramundi
Senior Member
- Location
- Chicago
- Occupation
- Licensed Residential Electrician
This is some twilight zone stuff for me. When did I become the guy crossing his arms across his chest, pouting, and stubbornly proclaiming "existing is existing." Haha. When did all you older sparkies get so progressive?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Jerramundi
Senior Member
- Location
- Chicago
- Occupation
- Licensed Residential Electrician
Responding to your fix...
I near absolutely agree. This is a potentially dangerous circumstance that should be corrected.
However, I'm not aware of anything in the NEC or Local Requirements that explicitly require he change this as part of a panel upgrade (i.e. merit inspection failure if not completed). *Pouts* "Existing is existing."
We're entering murky water here because it follows by the same logic that, anything after the OCPD, at least in terms of branch circuits, would then fall under the purview of a panel upgrade. Meaning we would be liable for not checking the entirety of not just one existing branch circuit, but all existing branch circuits, during a panel upgrade.
The only way I can see a panel upgrade explicitly meriting failure here are:
(1) If qualified as an MWBC (see next two, italicized paragraphs), the OCPD's would have to be correct as part of a panel upgrade per 240, which would trigger simultaneous disconnect requirements, thus requiring him to install the breakers on opposite phases by utilizing an OCPD w/ the proper disconnect requirements.
However, as @electrofelon pointed out, an MWBC by definition requires a voltage the two legs.
I'm not sure this would qualify as an MWBC...
Perhaps a dumb question, but what would you measure between two points of the same phase?
My initial reaction is 0 volts. But then I envision it as essentially cutting a single phase hot leg and measuring between the two points, which would certainly measure a voltage, I think.... There's also the idea of voltage / time and that you might still get a trickling of a reading.
If NOT qualified as an MWBC, the only thing explicitly required of him is sizing the breakers properly per 240, as part of a panel upgrade.
Could this pose a problem w/ the neutral? Absolutely, yes. Should it be corrected? Absolutely, yes.
But the load of a circuit is very specifically calculated, not represented by the figure on the breaker handle (as I'm sure you know), so there's no proof that it will overload the neutral, barring a quantitative analysis of the two circuits.
This would have to be separately addressed. Could the municipality levy something separate against the owner? I believe so, yes.
But fail a panel upgrade, explicitly substantiated by the NEC (other than simultaneous breaker disconnects),?? I'm not so sure... and again, murky water.
Other than all of the above, there's the blanket authority of the AHJ, where if the inspector notices something that he/she considers to be a high degree of danger, the have certain blanket powers they can utilize.
I near absolutely agree. This is a potentially dangerous circumstance that should be corrected.
However, I'm not aware of anything in the NEC or Local Requirements that explicitly require he change this as part of a panel upgrade (i.e. merit inspection failure if not completed). *Pouts* "Existing is existing."
We're entering murky water here because it follows by the same logic that, anything after the OCPD, at least in terms of branch circuits, would then fall under the purview of a panel upgrade. Meaning we would be liable for not checking the entirety of not just one existing branch circuit, but all existing branch circuits, during a panel upgrade.
The only way I can see a panel upgrade explicitly meriting failure here are:
(1) If qualified as an MWBC (see next two, italicized paragraphs), the OCPD's would have to be correct as part of a panel upgrade per 240, which would trigger simultaneous disconnect requirements, thus requiring him to install the breakers on opposite phases by utilizing an OCPD w/ the proper disconnect requirements.
However, as @electrofelon pointed out, an MWBC by definition requires a voltage the two legs.
I'm not sure this would qualify as an MWBC...
Perhaps a dumb question, but what would you measure between two points of the same phase?
My initial reaction is 0 volts. But then I envision it as essentially cutting a single phase hot leg and measuring between the two points, which would certainly measure a voltage, I think.... There's also the idea of voltage / time and that you might still get a trickling of a reading.
If NOT qualified as an MWBC, the only thing explicitly required of him is sizing the breakers properly per 240, as part of a panel upgrade.
Could this pose a problem w/ the neutral? Absolutely, yes. Should it be corrected? Absolutely, yes.
But the load of a circuit is very specifically calculated, not represented by the figure on the breaker handle (as I'm sure you know), so there's no proof that it will overload the neutral, barring a quantitative analysis of the two circuits.
This would have to be separately addressed. Could the municipality levy something separate against the owner? I believe so, yes.
But fail a panel upgrade, explicitly substantiated by the NEC (other than simultaneous breaker disconnects),?? I'm not so sure... and again, murky water.
Other than all of the above, there's the blanket authority of the AHJ, where if the inspector notices something that he/she considers to be a high degree of danger, the have certain blanket powers they can utilize.
Jerramundi
Senior Member
- Location
- Chicago
- Occupation
- Licensed Residential Electrician
Would this qualify as an MWBC? Or have I just had entirely too much coffee??
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Which "this"?
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
My head hurts.
-Hal
-Hal
DH Electric Co
Electrons, Chess, Bacon & Broads.
- Location
- Addison, IL
- Occupation
- Electrician
How would connecting it properly cause an issue?
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
How far are you expected to explore existing wireing?
Found one recently that during replacing a panel that I just happened to have opportunity during the replacement customer wanted a receptacle changed out (wrong color, didn't match the other ones in room). Existing panel was 20A breaker, 12awg wire in panel, at receptacle found 14 Awg wire in and out. Not sure when or where someone stabbed in a 14 on the 20A circuit. Would never had known if wasn't asked to also change that one receptacle. Now normally would replace like for like as long as no evidence in panel of issues. This instance triggered a whole lot of questions at least on this installation of how many other issues are there?
Changed that breaker to a 15A. But how far reaching does our liability reach when doing a "simple" panel change out? Cant be responsible for other previous hack jobs done that isn't within the purview of job you're hired for and not readily apparent, can we?
I just recently had a situation where, did a panel upgrade. And passed the inspection ( after haggling with inspector on a couple items).
powered everything back up, only to find a couple breakers would trip. Found out that someone had tied two circuits together after ocpd. Home was built in the 60’s ( one can only imagine what was behind those walls). Put my amp meter on the circuits and found no issues with overload. Told homeowners, they had no worries about potential hazards. ( did what they hired me for) collected my $$ and enjoyed the rest of my evening.
was I wrong in doing so??
Problem was corrected by replacing arc fault breakers with regular breakers. No more tripping
powered everything back up, only to find a couple breakers would trip. Found out that someone had tied two circuits together after ocpd. Home was built in the 60’s ( one can only imagine what was behind those walls). Put my amp meter on the circuits and found no issues with overload. Told homeowners, they had no worries about potential hazards. ( did what they hired me for) collected my $$ and enjoyed the rest of my evening.
was I wrong in doing so??
Problem was corrected by replacing arc fault breakers with regular breakers. No more tripping
Last edited:
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Why did you install afci's in the first place. They are not required on a panel change.
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
There are scenarios of mis-wiring. I laid out one I have encountered numerous times when I worked at a shop that had an 8-man rough-in crew.
Somebody would run a 3-wire home run to the second floor, let's say Master Bedroom on black, Master Bathroom on red. Somebody else would feed the Master toilet closet from the bathroom next to it, on a different circuit.
That Master Bathroom would be double fed.
Breaker out the panel and turn it all on. And if that rogue circuit is on black, it will have a 240v dead short. So, what to do? The guys in that hack shop would try up to 2 things :
1) swap the positions of the red and black in the panel. That would put the red on the same leg as the rogue circuit. No tripping now
2) if for some reason #1 didn't work (maybe a different problem) pigtail black and red to one breaker.
Now fast forward 30 years and do a panel change.
You connect all those circuits to what is correct.
#2 scenario is easier to see potential problem upfront because you'd have to take apart the pigtail to unland eveeything.
But suppose you have scenario #1 - you will now have the same 240v dead short that they had when the house was brand new.
What would be your fix?
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
I'm assuming the neutrals tied.
Why AFCI's? Now my understanding is that for simple panel upgrade/replacement replace like for like, no AFCI's unless extending circuit more than 6 ft.
The homeowner wanted to install them. The father was getting in their ear and saying that is what they should have. ( you tube electrician ). I explained that wasn’t required for a panel change but he insisted. So you know, customer is always right. And since he was paying
Yes sir
So, as not to start getting any type of bashing which many internet people do, I DON'T' condone wiring two circuits on the same phase using one neutral.
My concern becomes somehow, someway, the neutral is lost and I hit those two circuits with 240v.
Right or wrong, the thoughts that enter my mind are:
leave well enough alone
no good deed goes un punished.
I have done little no big deal fixes in the past and have wound up working for free for the day or paying to fix something, So I re think things now.
Also, true or false, I had heard years ago that a 14awg wire size is a 100 amp fuse. It doesn't justify doubling the circuit on it but it's a thought.
I've also examined some doubled up neutrals and they were "white" in color with no signs of brittleness.
(although I have seen where the conductor was a bit more brown and dryer, which also could have been from a loose connection as the discoloration was more around the terminal and as it wasn't as brown the entire length of exposed conductor in the panel)
Again I don't condone wiring which overloads the neutral, it just gets me thinking.
Thank you for the thoughts and advice.
My concern becomes somehow, someway, the neutral is lost and I hit those two circuits with 240v.
Right or wrong, the thoughts that enter my mind are:
leave well enough alone
no good deed goes un punished.
I have done little no big deal fixes in the past and have wound up working for free for the day or paying to fix something, So I re think things now.
Also, true or false, I had heard years ago that a 14awg wire size is a 100 amp fuse. It doesn't justify doubling the circuit on it but it's a thought.
I've also examined some doubled up neutrals and they were "white" in color with no signs of brittleness.
(although I have seen where the conductor was a bit more brown and dryer, which also could have been from a loose connection as the discoloration was more around the terminal and as it wasn't as brown the entire length of exposed conductor in the panel)
Again I don't condone wiring which overloads the neutral, it just gets me thinking.
Thank you for the thoughts and advice.
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