ECN Forum Forums General Topics of the Trade General Discussion Area One neutral or 2

Iwire & gentlemen:
Your reference to 210.4 (b) is for residential.....not comm or industrial.

IMHO, a multi-wire circuit should be on a common trip breaker, multi pole, or handle ties. This practice can prevent an incident or accident down the road.

It may not be "Code required" but it can be installed, and it may be in the job specs. If it's in the specs/design/prints, then it can be enforced by the AHJ.

John

John,
The AHJ has no business enforcing the design specs. That is between the contractor and the engineer. The inspector can only enforce the code as adopted by the local unit of government.
Don

Redsy, some good points as usual. I got the resi and industrial points of the code blurred together,again. I know, I know, it is the grounded conductor but I am so used to saying neutral, guess I need to get with the times. Thanks guys.

Hotline,


Of course it is, that was my point, there is no requirement for commercial or industrial as you know.

My customers would not like a short on one office cube circuit to take out 2 other circuits.

Now you will say do not run multiwire circuits, but I do not make the office cubes (modular office partitions) and if they are wired for common neutral that is just how it is, beyond that I prefer to use multiwire circuits.

I have never had an inspector stick his nose in job specs and will not listen to them if they do.

I have had many prints that show multiwire circuits and never have they asked for common trip.

Feel free to install common trip breakers if you like but I will not.

What accidents are you speaking of, only qualified people should be opening boxes in any environment but most certainly in commercial and industrial installations the servicing electrician should be aware of common neutral circuits.

Iwire summed it to a tee!!!
My thoughts exactly.
John

Look here:


The NEC doesn't tell you about the open neutral hazards when working on a circuit of this type, and too many have found out otherwise!

I always say that if you hear a "loud yell and then a thump" you'll probably find out that the reason was when someone was changing a ballast .... only those who are qualified persons will understand this hazard!

The rule cited above, has been in the code for many years and was designed to overcome the questions associated with common trip or handle tied circuit breakers in an offfice occupancy.

Note:

The new 2005 NEC may require "listed" instead of "approved" handle ties because in their wisdom some would allow a nail or piece of wire, and say that it is "approved"

See that definition in Article 100.

See also Article 605



[This message has been edited by Joe Tedesco (edited 06-14-2003).]

Joe
Please tell the partition manufacturers about 605.8. Have seen numerous multi wired light, switches and outlets in office partitions.
Are you saying we are not supposed to hook these up?

nesparky,
The rule does not apply to office partitions that you would be hooking up. It only applies to cord and plug connected ones.
Don

A qualified electrician will have learned one way or another about the hazards of a common grounded conductor. I always treat such conductors as live. The reason for the residential requirement is because Joe Smucketelli's brother-in-law would jump of his 12 foot ladder and break his handy neck on the TV.

[This message has been edited by Vickrey (edited 06-15-2003).]

[This message has been edited by Vickrey (edited 06-15-2003).]

Speaking of "...learning one wasy or another"

When I was first re-wiring my house (and unintentionally getting into the biz), I had switched the breakers off for the circuit in the 1900 I was replacing wire in. Went to strip the neutral for the branch circuit... strippers hit the side of the box and <<POP>> suddenly my 12ga stripper fit 10ga, and I saw purty lights!

Discovered the person who had messed around in the boxes before had piggybacked the neutrals from several circuits. (obviously)

Individual neutrals may be viewed as overkill, but I would think it makes for a safer installation.