I have a collegue who is doing a rewire on an old house (1928) The receptacles are all having new runs made to replace the old K&T with 12/2 romex. He wants to run a circuit from the new panel (a beautifully done 200amp center) into a juntion box in the ceiling above the den and then run individual runs out of the box to each outlet (4 total) in a radial fashion. I personally have never seen this, as I am used to the daisy chain method. I was wondering how you all felt about this? While I can't see anything inherently wrong with this, I wonder,is it allowable by the code. I have not seen it directly prohibited, but I may have just missed it. Opinions?

[This message has been edited by IanR (edited 03-05-2007).]

[This message has been edited by IanR (edited 03-05-2007).]

Nothing wrong with it, as long as that ceiling junction box is accessible after finish (blank cover?).

It may be the case that it is easier to fish wires from the walls into the ceiling space than to drill the studs and fish wire along the walls from box to box.

That is what he tells me. The old plaster walls are in good shape and they do not want to cut them up to run the new wires.

[This message has been edited by IanR (edited 03-05-2007).]

Thanks for the quick reply.

That's how the older brick homes are wired wher I live. The home runs are all to the ceiling boxes, from there the receps are fed. Of course there are not a lot of receps.

I've used both methods and actually prefer the "radial" that you mention, granted there is adequate access and work space in an accessible attic space where the junction is located. I even put a box above each room or area and then "spider" out from there when appropriate.

You'd be surprised how much easier finish is when you have only one cable coming into each outlet box. I personally find that the time savings in finish make-up out weighs the time it takes to screw in a box and install a few romex connectors.

Just make sure that box is big enough. You are talking about 11 conductors if I read this right. Add a couple more if this has a switch leg. You also have 5 whites under that big "cludge" nut. Electrically this is fine but mechanically it can be a chore to get this all back in there.

I also prefer this method. As the other person stated just be sure the box is big enough to handle the fill calculation. I find it much easier to run the cables and fish them thru the old plaster walls. I do not do much residential work but as long as the box is assessable (forgive my lousy keyboard skills) and big enough you will find this is a very simple way of doing this. Ive even done it on a new house. Once the boss saw what I did he liked it. Very neat and professional. et us know how this turned out.
Steve

Next time I am up that way I will try to take some shots of the finished work and post them here.
Thanks for all of the replies.

[This message has been edited by IanR (edited 03-05-2007).]

Keep in mind if the attic above could ever be finished these junction boxes will be a problem. I have dealt with this before and it can be a pain to get them outa the way.
Ob

The same can be done by going box to box through the attic - fish down both ends from above.

"Keep in mind if the attic above could ever be finished these junction boxes will be a problem."

Luckily, that is unlikely. I am told, it is more of a crawl space than an attic.

Here's a similar principle which was once used to centralize lighting/switch wiring in some British homes:
https://www.electrical-contractor.net/ubb/Forum5/HTML/001312.html

That is a very interesting looking box. Very orderly yet, kind of intimidating to look at

quote"You also have 5 whites under that big "cludge" nut. Electrically this is fine but mechanically it can be a chore to get this all back in there."

Agreed. The big groupings can be split up by bridging a single conductor between two sets of wire nut splices. That one conductor will be no different than the home run conductor. That will make folding the two sets back in the box less taxing than the single bunch, and for my two cents worth, a safer splice than a bunch all stuffed into a big blue wirenut.

The old Austrian/German version was: have a big junction box in the wall, usually where the feed enters the room and one in a direct line from the ceiling light fixture, parallel to the joists/beams. If you're lucky those two can be combined. Then distribute additional boxes to achieve runs to every receptacle and switch with no more than one 90 degree conduit bend. For example if you have 3 receptacles on one wall, put a box above the center one, run the feed straight down and to the left and right. Once painted or papered over the blank covers are still accessible (though you could argue if the paper job is done too well) but not too obtrusive.
Of course, using cable instead of conduit allows having more bends, but still, that method makes it REAL easy to figure out the layout servicing that install. Like you have the aforementioned 3 receptacle boxes, ech with the feed entering from the top. Above the center receptacle you have a junction box with two conduits from the left, one from below and one to the right - easy to guess the top left is the feed and the other three feed the receptacles.

Radial or daisy-chain? I never quite thought of it in those terms.

Both are completely acceptable to me.

"Radial" seems to be the preference for running pipe, and where junction boxes are very accessible.

"Daisy chain" is most often found where Romex, MC, or some other sort of cable is used.

The method chosen seems to be determined more by the overall construction style, than any 'merit' to the various methods. For example, in those places that require pipe, a receptacle is far more likely to be tied into the one a floor above it, than to another one on the same wall. This is because it's a lot easier to drill one hole in a top plate, than a hole in every stud.

IanR,
One handy trick I have found works well for cutting in old-work boxes is to cut the plaster with a 2" grinding wheel chucked up in a drill motor or other rotary tool. The lath and plaster does not seem to break up as badly. This works pretty well with tile and brick also. You would want to have a vaccuum running to catch the dust.

Or else use a variable speed jigsaw to cut a receptacle into the baseboard using slow speed so as not to shake the wall (orienting the box horizontally instead of vertically). A dark brown receptacle and cover blends with the wood.

"Radial".

I've always called that method "Umbrella".

Some guys whose house blog I'm reading complained recently they would like to have baseboard receptacles in their new addition but code doesn't allow it because they would be below some minimum heigth... don't know where in the U.S. they're located.

I've seen arguments here about circuit arrangements. The British IEE Wiring Regs. define certain standard circuit arrangements, including radial circuits.

Some seem to take the listed arrangements as absolute and insist that a radial circuit has to start at the panel, run to each outlet in turn, ending at the last one.

Others claim that there is nothing wrong with a "tree" arrangement to a radial circuit in which you can branch off at any point which is convenient.

I'm firmly in the latter category.

Tex, that must be a local rule. Location of receptacles is not really addressed that specifically. Pretty much anything within 18" of the wall on the floor up to 5½ feet on the wall will fulfill 210.52(A). I suppose a local AHJ can change that any way they want.

ADA boilerplate:
http://www.access-board.gov/adaag/html/adaag.htm

4.2.5* Forward Reach. If the clear floor space only allows forward approach to an object, the maximum high forward reach allowed shall be 48 in (1220 mm) (see Fig. 5(a)). The minimum low forward reach is 15 in (380 mm). If the high forward reach is over an obstruction, reach and clearances shall be as shown in Fig. 5(b). Appendix Note

This is the phrasing that limits switch box heights and forces receptacles up from the floor.

Hence the California Title 24 specifications that boxes be set at 46” AFF ( switches ) and 18” AFF ( receptacles ).

GFCI receptacles within bathrooms are typically set at 42” or 44” AFF... Back splashes and sinks being slightly higher in commercial.

Title 24 does not address the height of boxes.