chauss
Member
- Location
- Powderly, TX
Has there been a change in the code that I don't know about yet that says you can not share a neutral in a branch circuit?
shared neutral
- Thread starter chauss
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
No, handle ties and identification of the grouping in the panel is now required.
chauss
Member
- Location
- Powderly, TX
Thanks Jumper. Didn't think there has been have a few electrician here in southeast Oklahoma that don't know how it works, they pull a separate neutral for every circuit. If there 3 circuits there are 3 neutrals. Telling managers at casino we are wiring incorrectly and dangerous.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Although there are new requirements for MWBC's they are still permitted. Whether or not they're more dangerous could be the subject of debate. Most of the the problems with them are because of human error.
buddhakii
Senior Member
- Location
- Littleton, CO
Installing MWBC's is dependent upon what you are providing power to. In a house I would have no problem running shared neutrals. But when you are powering up expensive equipment it's not a good idea.
symphony2011
New member
- Location
- Muncie IN
Shared Neutrals in a house.
Shared Neutrals in a house.
I was always taught the reason we can share neutrals in a 3 phase building is because we can balance the neutral on a 120/208 or 277/480 system.
Houses are normally single phase so you can not balance the neutral load. THus you can not share neutrals.
Shared Neutrals in a house.
I was always taught the reason we can share neutrals in a 3 phase building is because we can balance the neutral on a 120/208 or 277/480 system.
Houses are normally single phase so you can not balance the neutral load. THus you can not share neutrals.
John120/240
Senior Member
- Location
- Olathe, Kansas
Yes houses are usually 240/120 single phase. Yes you can share neutral conductor. Run 14-3
or 12-3 romex, one hot & neutral go that way, the same neutral & other hot go this way.
The neutral is required at all switch locations to facilate electronic devices such as occupancy
sensors. (this requirement is when using romex)
Typically circuits to electronic gaming machines do not utilize MWBC's so the others may be refering to a spec.
Roger
The neutral carries the unballanced neutral current so MWBC's are perfectly fine in single phase applications excluding AFCI's and some GFCI applications.
Roger
I agree with Roger. To add, if the neutral carries the unbalanced load, it can never carry more than rated breaker whether single or two-pole.
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liquidtite
Senior Member
- Location
- Ny
can some one explan the difference between a balanced load and an unbalanced load and a circumstance witch this may occur,
liquidtite
Senior Member
- Location
- Ny
on the un balanced load why does it show current going back to the source on line 2?does unbalnced loads only occur in mwb's can you describe when this mite happen thanks for your time.im hacving trouble following the diagram
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The term "unbalanced load" could fit many situations, but, in terms of loading neutrals, yes, it only refers to MWBCs. If you install a dedicated neutral for each branch circuit, the current will be equal in the neutral and phase conductors. In MWBC the neutral only carries the "unbalanced" or "unequal" load.
Yes, unballanced loads only occure in MWBC's. (excluding any wiring problems in a two wire circuit) In a two wire circuit the ungrounded and grounded (neutral in todays NEC) carry the same current.
Roger
- Location
- New Jersey
- Occupation
- Journeyman Electrician
One other thing to note. Roger's graphics are for a 1?, 120/240 volt system. The same MWBC in a 208Y/120 volt system would have a neutral current that can be equal to the phase current.
There are a few companies out there making 2pole AFCI "combination type" breakers, GE mod3 is one, and Murray is another.
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