Neutral and hot jumpers for duplex outlets

[mwm1752]

I don't claim it to be non practical to not pigtail beyond the "shared" portion of the neutral conductor - there is just some room in definitions to interpret a MWBC to be the "entire" circuit not just the portion that is sharing the neutral. FYI I do not generally pigtail the neutrals myself in the non shared neutral portions of MWBC's.

I agree the definitions need tweeking which is the reason for my post --
My agreement with iwire is based on theory ---- prior to the simontaneously disconnecting means, it would certainly support no load path on any portion of the grounded conductor, in a compliant 2 wire circuit, that is turned off, past the last j box in which the multi conductor wiring was present. The SDM protects individuals when opening the GC path that serves both of the MWBC conductors, which can only be possible when they exist in the same j box.

 

[jaylectricity]

The backwired connections I am looking at/using are screwed clamp connections. I saw the post about the receptacles with the hot having two clamped connections and two stab connections. But I've never seen one.

Really? Because that's what you get from Leviton and Pass&Seymour.



Or were you adding "clamp" yourself and picturing something else?

 

[iceworm]

Really? Because that's what you get from Leviton and Pass&Seymour.

View attachment 10887

Yes, really. No - it may be what you get. I don't

... Or were you adding "clamp" yourself and picturing something else?

Interesting concept, but no, I'd leave something like that to a real electrician.

And no, I'm picturing what I posted in the link. Possibly that would be apparent if you looked at the link.

ice

 

[GoldDigger]

Yes, really. No - it may be what you get. ...
...
And no, I'm picturing what I posted in the link. Possibly that would be apparent if you looked at the link.

ice

When I follow that link (even in Full Site rather than mobile version) I do not see enough detail to be sure one way or the other.

 

[iceworm]

When I follow that link (even in Full Site rather than mobile version) I do not see enough detail to be sure one way or the other.

No, there is not a picture of the back side at the link. But there should be enough detail to see they are not the same as the jaylectricity picture.

I feels like I'm being asked to find a picture to prove I'm not as dumb as some house electricians are. Either direction, that's degrading. I really don't want to go there.

ice

 

[GoldDigger]

No, there is not a picture of the back side at the link. But there should be enough detail to see they are not the same as the jaylectricity picture.

I feels like I'm being asked to find a picture to prove I'm not as dumb as some house electricians are. Either direction, that's degrading. I really don't want to go there.

ice

I would never (well hardly ever) disrespect you. But you were the one who suggested looking at that link.

 

[iceworm]

. But you were the one who suggested looking at that link.

Yes. I did. In an equally respectful manor I will suggest I don't have any further help. I'm at a loss when honest-to-god-real-live-not-in-captivity-not-as-seen-on-TV, electricians are not familiar with commercial grade, back and side wired receptacles. Not you, of course. I know you do.

ice

 

[jaylectricity]

No, there is not a picture of the back side at the link. But there should be enough detail to see they are not the same as the jaylectricity picture.

I feels like I'm being asked to find a picture to prove I'm not as dumb as some house electricians are. Either direction, that's degrading. I really don't want to go there.

ice

Perhaps I was unclear as to what you "had never seen before."

 

[iceworm]

Perhaps I was unclear as to what you "had never seen before."

Well, as I said in post 5

The backwired connections I am looking at/using are screwed clamp connections. I saw the post about the receptacles with the hot having two clamped connections and two stab connections. I've never seen one. ...

As I said:
I don't wire houses - I'd be too slow, too inefficient compared to someone that does it for a living. I'd starve to death before I finished the first one. I'm sure there is plenty of stuff, in common use, I haven't seen.

Ice

 

[brother]

I don't claim it to be non practical to not pigtail beyond the "shared" portion of the neutral conductor - there is just some room in definitions to interpret a MWBC to be the "entire" circuit not just the portion that is sharing the neutral. FYI I do not generally pigtail the neutrals myself in the non shared neutral portions of MWBC's.

I agree with this statement, especially since my area has adopted the 2014 NEC. As most know, there were alot of old circuits that shared neutrals, even emergency circuits. If you tried to extend, even just a 'hot and neutral' for one emergency circuit for a receptacle, most inspectors would not accept the arguement of that 'portion' of the circuit is not part of a multiwire branch circuit because it dont meet all the definition of it. For the sake of code language and the original intent of the code to prevent common disconnects on emergency circuits, this would not be allowed.

Also, in hospitals there are alot of old existing circuits there too that have shared neutrals both normal and emergency. If you tried to extend even the normal power for patient rooms just for one receptacle, this would not be accepted. I just dont see how one can accept just 'part' of the circuit being multiwire and not the entire circuit at least from the intent of the code.

 

[don_resqcapt19]

... I just dont see how one can accept just 'part' of the circuit being multiwire and not the entire circuit at least from the intent of the code.

The intent of the code is exactly why you can say that the two wire part of the circuit is not a MWBC.
The intent of the code is to prevent "open neutral" problems on a circuit where a single neutral is used with more than one ungrounded conductor when you remove a device. Once you are down to a single ungrounded conductor and a neutral, there is no longer an "open neutral" problem if you removed the device and the neutral is disconnected.

 

[GoldDigger]

And if you want to put a disconnect on the two- wire branch from the MWBC, it does not have to interrupt the third wire, which is not there.

 

[brother]

The intent of the code is exactly why you can say that the two wire part of the circuit is not a MWBC.
The intent of the code is to prevent "open neutral" problems on a circuit where a single neutral is used with more than one ungrounded conductor when you remove a device. Once you are down to a single ungrounded conductor and a neutral, there is no longer an "open neutral" problem if you removed the device and the neutral is disconnected.

I understand your point Don, however I think you missed mine. I was referring to the other part of the code that forbade the sharing of neutrals in emergency circuits and in hospital care areas. Do you really think an inspector would allow one to extend an existing circuit that came from a multiwire branch circuit for either of the 2 examples I gave?

 

[iwire]

I agree with this statement, especially since my area has adopted the 2014 NEC. As most know, there were alot of old circuits that shared neutrals, even emergency circuits. If you tried to extend, even just a 'hot and neutral' for one emergency circuit for a receptacle, most inspectors would not accept the arguement of that 'portion' of the circuit is not part of a multiwire branch circuit because it dont meet all the definition of it. For the sake of code language and the original intent of the code to prevent common disconnects on emergency circuits, this would not be allowed.

Also, in hospitals there are alot of old existing circuits there too that have shared neutrals both normal and emergency. If you tried to extend even the normal power for patient rooms just for one receptacle, this would not be accepted. I just dont see how one can accept just 'part' of the circuit being multiwire and not the entire circuit at least from the intent of the code.

You are bringing in an entirety different issue.

The part you are extending from IS a two wire circuit that happens to be supplied from a MWBC. That being the case you can't extend it.

 

[iwire]

I understand your point Don, however I think you missed mine. I was referring to the other part of the code that forbade the sharing of neutrals in emergency circuits and in hospital care areas. Do you really think an inspector would allow one to extend an existing circuit that came from a multiwire branch circuit for either of the 2 examples I gave?

I am not Don but no, you could not extend from a MWBC, that is not even in question.

 

[don_resqcapt19]

I understand your point Don, however I think you missed mine. I was referring to the other part of the code that forbade the sharing of neutrals in emergency circuits and in hospital care areas. Do you really think an inspector would allow one to extend an existing circuit that came from a multiwire branch circuit for either of the 2 examples I gave?

I thought we were talking about the code intent for 300.13(B).

That is totally different from the intent of the code sections that you are talking about. In general the intent of those sections is to get away from the common disconnect requirement for MWBCs...not because there is any problem with the use of MWBCs.

 

[brother]

I thought we were talking about the code intent for 300.13(B).

That is totally different from the intent of the code sections that you are talking about. In general the intent of those sections is to get away from the common disconnect requirement for MWBCs...not because there is any problem with the use of MWBCs.

The highlighted red is what I am addressing in your post. I am well aware of the common disconnect issue. I stated that in my original post #30, go read it again. What I am getting at is the 'definition' issue from the NEC which is where this thread lead to from the op question of a required pigtail or not of 300.13(B), which would lead you to the intent for those articles as well. I will try to connect the dots here.

Since that part of the circuit is no longer an MWBC (or is both an MWBC and a single branch circuit?) the rule should not apply there.

I would agree there is very little real danger of the loose neutral having voltage at this point, I would have to disagree and say this is still part of the MWBC.
post #8

While I agree with you both, note that the branch circuit extends fully to the wiring path to end of line, and yet the final OCPD defines the branch circuit as multiwire.

Branch Circuit. The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.

post #14 iwire's response to mwm1752

Once the MWBC splits out it no longer fits the defintion you posted.

post #16

There is nothing to argue about.

Once you are down to a 12/2 cable for instance there is only one ungrounded conductor making it outside the definition of a MWBC.

This is one of the reasons for my comment. If we accept this interpretation, then it would have to apply to 2014 NEC 700.19 and 517.18(A) as well which states

517.18(A) ....Branch circuits serviing patient bed locations shall not be part of a multiwire branch circuit
700.19 Multiwire Branch Circuits. The branch circuit serving emergency lighting and power circuits shall not be part of a multiwire branch circuit.

The definition of a MWBC was not modified by those articles, so the original definition still stands. So in the examples I gave concerning a hospital and emergency power in any location, you would have to accept that the end of the line, (ie the outlet) is still part of the mwbc and the rules surrounding mwbc applies.

And also

post #34

The part you are extending from IS a two wire circuit that happens to be supplied from a MWBC. That being the case you can't extend it.

If everyone notice from the section 2014 NEC 700.19 and 517.18(A) the word 'supplied' is not there. It says 'part of'. If one cannot extend that 2 wire portion of the circuit because it is 'part of' the circuit, which according to some is not a mwbc because of the 2 wire, then the same rule applies to other areas as well. All end of line outlets would still be part of the mwbc even with the break away to just 2 wire, not because of a danger of opening the grounding conductor because in theory there is none, but because of the application of the definition of a mwbc.

 

[kwired]

The word intent has come up a lot in recent posts. When it comes to NEC intent it is either assumed or you have to go back to when a particular section was last changed or introduced and read the ROP's and from there you may be able to get an intent from the CMP as to why they worded it as it is.