ECN Forum Forums General Topics of the Trade General Discussion Area Neutrals in Panel Upgrade w/Junction Box

For running the separate conduits?

Non in metal conduit or boxes, you won't

300.20 Induced Currents in Metal Enclosures or Metal Raceways.
(A) Conductors Grouped Together.
Where conductors carrying alternating current ar installed in metal enclosures or metal raceways, they shall be arranged so as to avoid heating the surrounding metal by induction. To accomplish this, all phase conductors, and where used, the grounded conductor and all equipment grounding conductors shall be grouped together

[This message has been edited by electure (edited 08-02-2006).]

Dnk, I would question the accessibility of a sub panel in an attic. You might also see some problems with ambient temperatures down here.

I don't know what he's got gfretwell.

He may have an old victorian style with them big attics, or a little cape cod with no access.

Just thought I'd through it out there....

My parent's attic has a 50 or 60 degree slope each side, so it's 30' tall roughly. Gets over 150 degrees in the summer, but there is great access (pull-down ladder from 1927, no hinges- all one big unit that puls out and down). It's really nice to work up there, you can get 4'+ height right next to the edge of the attic.

I really resent that post. ;-)

I'd like to resurrect this discussion because I have several installations where I am probably out of compliance. Many times when upgrading to a larger panel I reuse the abandoned box as a junction box, gutting the interior but leaving the neutral bar, then covering the old panel with a sheet of tin. Sometimes I have set a separate ground bar & pulled all the bares off the neutral bar. I then typically run a #8 ground and a #6 neutral to the new panel in an oversized raceway, along with the circuit conductors. For residential I have used # 12's-the distance usually is 10-15 feet and the load diversity in homes is so great that I have never experienced any problems. I understand the derating part of the code, but also fall back on Table B 310-11.
In another area of this thread the remote J box to collect exist circuits was discussed. I have several commercial jobs where I pulled 12-# 10's, 1#8 Gr. & 1#6 N into 12.12.6 boxes above restaurant kitchen ceilings. I fab'ed. a neutral bar by splitting a length of 1-1/4 pvc lengthwise, bolting a gr. bar to this, then bolting the assembly to my junction box. (this also can serve as a quick, inexpensive isolated ground bar)Sometimes I have landed the hots on a barrier terminal strip, other times I make them up with Scotchloks. All the branch appliance circuits are fed into this box(# 12 MC)As I recall, the inspector guy looked at my work and smiled, gave me the OK. What I'm getting from the discussion is that I should run 2 pipes to cut the number of current carrying conductors down. Your comments are appreciated. And thanks for the information on the supplemental X-10 hardware.

As soon as you run 2+ pipes, you need to keep track of your neutrals...the neutral for a circuit must be in the same pipe as the hot. So, in your case, you'd have 2 neutral bars, and 2 neutral wires, one in each conduit. But, you could use smaller HR wires on your hots. You'd have to decide which option makes more economic sense. My feeling is that if it's a long conduit run, I'd rather have oversized conductors if it means I only have to run and pull through one conduit, but with today's copper prices, maybe 2 smaller pipes makes more $$$ sense. Perhaps somebody here that has all the pricing in a estimating program could give us rough numbers?

As for your neutral bar, that's fine in a pinch, but you should really use a listed, factory built neutral bar if you do this a lot. If I opened up your Jbox and saw that, I might doubt other aspects of your installation.

FWIW, I've used the DIN rail terminal blocks(on the hots) for setups like this, they are quick to assemble, and there is no crimping, etc.

"What about putting a sub-panel in the attic?"

If the attic is not a goood location, than there may be another location, but the sub panel may be a better way to go.

I put one in an attic once... But it was a rare situation.

It had the headroom and workspace and access.... And it rarely ever breaks 80F here.... There were also two AC units in there too, doubt they ever get used.....

As far as getting neutrals mixed up, band them together with thier conductors with tape, or number them with thier circuit numbers. Number books are cheap.... Tape is real cheap!

Almost Fried, I have done simular things with using an old panel as a junction box and leaving the nuetral bar and grounds, but only under 2' ands in a large nipple so it fell under the 2' rule for derating. You might be able to go a further distance in a gutter... But not 2 conduits. (Magic number is 9 or it is a waste of copper to up-size IMO) And I don't think I would ever MAKE a neutral bar.