Circuits Conductors

[Alwayslearningelec]

Can someone please elborate on this for me?

I have two notes on my drawings

1. All branch circuits shall have a dedicated full sized neutral conductor.

Does this mean what it says that I need a separate neutral for every circuit. I was uinder the impression that you can sometimes share a neutral for up to threee circuits.

2. Furnish and install a green insualted copper ground conductor in all power feeder conduits with a phase & neutral conductors.

So this means exactly what it says but for FEEDERS only.

Thanks for the help


And on a side note..... I really appreciate all help you guys give me with my questions. I really think a lot of you guys on here really know you SH&% about electrical business. THere are people I come across on the office side that seem to know a lot less than they portray..

 

[Dennis Alwon]

Can someone please elborate on this for me?

I have two notes on my drawings

1. All branch circuits shall have a dedicated full sized neutral conductor.

Does this mean what it says that I need a separate neutral for every circuit. I was uinder the impression that you can sometimes share a neutral for up to threee circuits.

Yep that is what it means. The NEC allows sharing the neutral however for whatever reason the engineers want a dedicated neutral. The full size is probably in reference to feeders etc where you may be allowed to have a smaller neutral, as in a service, however that is not allowed for this job.

2. Furnish and install a green insualted copper ground conductor in all power feeder conduits with a phase & neutral conductors.

So this means exactly what it says but for FEEDERS only.

Sounds like it to me.

And on a side note..... I really appreciate all help you guys give me with my questions. I really think a lot of you guys on here really know you SH&% about electrical business. THere are people I come across on the office side that seem to know a lot less than they portray.

Aw shucks it ain't nothing.:grin: You are very welcome.

BTW we all tend to show our brighter side even if it is a little dark.

 

[growler]

Can someone please elborate on this for me?

I have two notes on my drawings

1. All branch circuits shall have a dedicated full sized neutral conductor.

Does this mean what it says that I need a separate neutral for every circuit. I was uinder the impression that you can sometimes share a neutral for up to threee circuits.

2. Furnish and install a green insualted copper ground conductor in all power feeder conduits with a phase & neutral conductors.

So this means exactly what it says but for FEEDERS only.

Thanks for the help


And on a side note..... I really appreciate all help you guys give me with my questions. I really think a lot of you guys on here really know you SH&% about electrical business. THere are people I come across on the office side that seem to know a lot less than they portray..

First, you can consider these notes as part of job specifications and job specs supersede the NEC. The NEC is what you are allowed to do but the job specs are what you are being paid to do. So long as the job specs meet or exceed the NEC requirements then that's what you are bidding on unless you can talk them into changes.

It's not uncommon for a dedicated neutral to be requested. And yes they want one for each hot conductor. ( More money, that's a good thing).

Yes they do say power feeder conduits but I would question this one just to make sure. The fact that they say green would make me quesion it as many feeders wouldn't need to be green but could be marked green ( they will be large enough ). They may really want grounds pulled in all conduits and just got it worded wrong on the notes. I would check with the designers, they do want a dedicated neutral and that would be reason enough for me to question this.

You can try looking at th E drawing and see how many conductors are shown for each circuit. Some are marked that way. Little slash marks. If you see a receptacle with three little slash marks that a good indication of a ground needed.

There is nothing wrong with having questions because some drawings are not as clear and easy to understand as others. Even notes may need clarification.

 

[S'mise]

... to the letter

... to the letter

I would follow the exact wording.
Insulated egc in feeders (only) and dedicated (individual) neutrals in branch circuits.

Note; a multiwire is considered one circuit

I don't see why they would want insulated egc all the way back unless they have isolated ground recepts.

Share a neutral for up to three cks? I have never heard that

 

[charlie b]

Share a neutral for up to three cks? I have never heard that

Yes you have. You even mentioned it (MWBC) earlier in your post.

Note; a multiwire is considered one circuit

That is not what the NEC says. Take another look at the second sentence of 210.4(A).

 

[K8MHZ]

I would follow the exact wording.
Insulated egc in feeders (only) and dedicated (individual) neutrals in branch circuits.

Note; a multiwire is considered one circuit

I don't see why they would want insulated egc all the way back unless they have isolated ground recepts.

Share a neutral for up to three cks? I have never heard that

Three single phase circuits from a three phase panel, perhaps?

 

[Dennis Alwon]

Note; a multiwire is considered one circuit

That is true for some situations. art. 225.30 specifically states

for the purpose of this section, a mwbc shall be considered a single circuit.

 

[Volta]

...1. All branch circuits shall have a dedicated full sized neutral conductor.

Does this mean what it says that I need a separate neutral for every circuit. I was uinder the impression that you can sometimes share a neutral for up to threee circuits...

Yes, separate neutral for each circuit.

I would follow the exact wording...

I agree, especially if this is a competitive bid.

Share a neutral for up to three cks? I have never heard that

Ok for a wye system. Or for feeders 215.4(A)

 

[SparkyHC]

As one of those engineer's who also has notes very similar to those described here, I would like to pass on things that I have seen over the years...(I started a while ago as an electrician and still hold a license)....
Regarding ground wires, when conductors are installed in conduit you may be allowed to rely on the metal conduits as the equipment ground. I've seen the molten slag dripping from the ceiling tiles where a conduit located above had a connector with loose set screws....the cost of the fire, clean-up and misc. replacement was far in excess of the ground wire which could have been installed the first time......and as was pointed out by one the esteemed members on this site, "something you make money for installing". Yet so often I get phone calls and arguments requesting the conduit be allowed as the EGC.

Ah, next "Neutral Sharing", another pet peeve and the source of large scars that some of still carry......A project not so long ago with a multi-acre parking garage and a lot of parking stall signs. At the point when the installing contractor's were done I was called in for the "punch list" and found many of the shared neutrals were carrying between 100% to 250% of the branch circuit rated current. As in the story above the cost of repairing the poor wiring installation delayed the customer's grand opening and cost far in excess of the neutral wires that were not installed the first time around.

Now, I apologize to all of the "Artisans" of the electrical construction field who could easily have installed the above systems without ever finding any negative results and genuinely care about their work.....I am just disappointed that the I managed to find the few who did not.

p.s. When the engineer says "no" to a request like those above, first of all try to understand there may be a reason.......second thank him fo the additional revenue.

Sincerely,

HFC New Jersey PE

 

[S'mise]

duh

duh

Oh, I see. 3 phase multiwire. (I was thinking about single phase)

thanks for the clarification

 

[Volta]

... a connector with loose set screws...

Speaks for itself.

... found many of the shared neutrals were carrying between 100% to 250% of the branch circuit rated current. As in the story above the cost of repairing the poor wiring installation delayed the customer's grand opening and cost far in excess of the neutral wires that were not installed the first time around.

That problem was not caused by proper sharing of neutrals in MWBCs.

 

[growler]

That problem was not caused by proper sharing of neutrals in MWBCs.

That's true but the potential for a mistake is always there. That's why I like to see the phases marked. If multi-wire branch circuits are used and the phases color coded the will eliminate some of the risk. ( black, red, blue or brown, orange, yellow).

Even when you keep the phases marked that doesn't mean the next guy will understand what's going on but it does make a mistake easier to spot. He may still a have a black and red wire on the same phase sharing a return with double the current potential.

If each hot conductor has it's own return ( neutral) that pretty much eleminates the possibilty of that mistake. Either you hire competent people to maintain a system or you try to make the sytems as idiot proof as possible.

Or you can use the alternative method, you build as quick and cheap as possible and hire the most incompetent people you can find to maintain it and hope you have good insurance. It's the American way.

I may be getting a bit cynical.

 

[don_resqcapt19]

...
Now, I apologize to all of the "Artisans" of the electrical construction field who could easily have installed the above systems without ever finding any negative results and genuinely care about their work.....I am just disappointed that the I managed to find the few who did not.

And you really expect that those same electricians who did poor quality work before will provide you with a quality install just because you change the specs? In some cases they probably won't even follow those specs.

 

[jes25]

My boss routinely ignores specs for things like extra neutrals. Although, I admit I don't know what he may have worked out with the owners beforehand

 

[walkerj]

It seems like I am the only person I know that follows the specs

Right now and I am doing a hotel and a seperate neutral for each circuit is spec'd along with a ground for every conduit or cable.

 

[Volta]

It seems like I am the only person I know that follows the specs

Right now and I am doing a hotel and a seperate neutral for each circuit is spec'd along with a ground for every conduit or cable.

Then we'll have to meet someday .