Need some advice about wiring basement

[BIOSMonkey]

I am finishing my basement and need some tips on how to do a few things for rough in. I am in Gwinnett County, GA if that matters.

Specifically:

1) I definitely will have some sort of drop ceiling, probably acoustic tile but there is a small possibility it may be sheet rock. The ceiling will drop about a foot or so from the bottom of the joists. a) I assume that any electrical runs to lighting in the ceiling (cans, etc) will require armored cable since the wire is unsupported/unprotected from the joist to the tile? b) I also assume that this means I will need to terminate the NMB cable into a metal junction box, and run the armored cable from there to the fixtures? c) for rough-in there will be no actual fixtures...so how do I terminate the armored cable? Or do I not run any armored cable at all until fixtures are there?

2) What is used to rough-in wall lights (for example the bathroom), a standard circular fixture box like they used for the ceiling?

3) Will the inspector examine only what I have done? ie if he/she sees something that is sloppy but was done by the home builder, could I be required to fix it? That would seem rather unfair since THEY were supposed to get it inspected to get the CO...

[v]

Wow. How high is your basement? That is unusual, to have enough room in a basement to drop a foot and still have decent ceiling height.

Reply to NG only - this e.mail address goes to a kill file.

[J.A. Michel]

9' basement walls are common in new construction.

[Colbyt]

Save yourself at lot of worry. Formalize your intentions and try to meet with the inspector at his office before you start work. Explain what you plan to do and ask if that is correct for your area. I have never found any inspector unwilling to work with a homeowner who cares enough to want to do it right.

Why do you want to drop the ceiling?

Now to try and answer a few of your questions. These answers are based on this locale. Each area has their own little quirks even though they all use the same code.

1. There can be no junction boxes concealed above a drywall ceiling. All junction boxes must be accessible. I don't know about armored for the one foot drop. I do know that nm can not run across a metal grid for a dropped ceiling. In a normal situation without the drop NM is run to each can light.

1. yes or possibly a switch box it depends on the fixture. For some fixtures you just have the wire there for the rough in and make the final connection inside the fixture.

2. Normally yes

Colbyt

[BIOSMonkey]

Because I have to. Duct work, gas lines, water lines etc run all across under the joists.

I had thought about this because I knew junction boxes could not be enclosed. I guess the only way to do this correctly (ie dropped drywall) is to run armored cable everywhere? I don't know how I could do that logistically, and it would require significant rework.

[gfretwell]

U would use MC cable instead of AC but your idea is sound. Mount a metal box where the light will go and run a short MC whip to the light. A box over a suspended ceiling is still accessible.

Yoiu install the box on the rough, install whip when you install the light on the trim.

Yes

He should only be looking at what you put on the permit.

[tim]

BIOSMonkey wrote in news: [e-mail]:

Most drop-in fixtures (cans, flourescents, etc.) have a builtin box or box-like connectors so that the junction is made inside the fixture (i.e. armored to first can - wired to first can and armored to second can. Armored to second can wired to second can and armored to third can.) You would just run NMB to each light locations and leave an extra two or three feet of wire in a loop there. Then when installing the fixture, cut the loop, make the connections inside the fixture, finish the install, and go to the next. If you are not sure about wanting a light at a specific location, leave a loop anyway. Too many DYIers worry about 'wasting' wire and wind up not leaving enough to make a proper connection. In the total cost of the project, NMB is cheap.

[BIOSMonkey]

More questions:

1) In order to add enough circuits in my breaker box, I may have to double up some of the breakers. We had a new heat pump system installed and the HVAC guys stole a lot of space!

I really only have one breaker space left, and 2 more circuits to run (1 20A for bathroom and 2 15A for bedrooms), BUT some of the other breakers are single and could potentially be converted to two small breakers. What are the rules regarding this? I am wondering why some are single and some are double...why not just make all of them double to leave space?

2) Does the bathroom circuit have to be dedicated to the GFCI outlet ONLY or can it also feed the vanity lights?

3) Can NM cable be run diagonally under the joists, or must it follow the inside of the joist or through holes? (remember I will be doing a drop ceiling)

[PipeDown]

When you buy a box, its listed max capaciy usually is with double breakers.

In most later model boxes, a double breaker will be fed by one phase of the

240V. In some older boxes the double breaker might actually be fed by both phases (as if they were seperate breakers). This differentiation really only becomes important if you are using 3 conductor romex and trying to use one neutral for two hot branches. In that case, the two branches should be fed by different phases in the breaker box. If all your branch circuits are wired on 12-2 romex, you probably don't have to worry about which phase you are connecting to.

Run 20A to the bedroom unless the wire is 14# If you have 12# wire give it all the juice it deserves. In many areas, AFCI breakers are required for bedrooms. These usually only come in full slot size (no doubles). AFCI are not available in receptacles like GFCI and must be in the box. Check your city to know if it is required. I like GFCI in the bedroom also.

If you trip the breaker, you'll be fishing around in the dark looking for the reset. Not sure of the code on that one. Can wire the light to the bedroom lighting ckt. If the fixture has a plug, it should be GFCI also.

If the joists are in an inaccessable area not likely to be touched or stepped on, it would be OK. If the cieling is suspended in such a way that one could not put a nail through a cable it should be OK. Concieling the wire is a better practice. Check with your city, they might want you to use armored cable in that situation.

The little "Code Check Electrical" book is a very concise resource containing all the answers you seek and can be purchased at most big box hardware stores.

[Mark]

if you use the tiles instead of the sheet rock to drop the ceiling then you will be able to access the junction boxes as well as the ducts and pipes and all the other things that may need service up there.....

Mark

[Chip C]

Your box will indicate somewhere what its max circuit capacity is; this will probably permit some but not all of the breakers to be doubles. For example, if the box has 50 slots it may permit 60 circuits, so 10 of the breakers can be doubles. Be aware that you may need to add extra neutral (and less probably, extra ground) bus bars; unless the panel says so explicitly, don't try to put more than one neutral wire under one neutral bus screw. I *think* you can usually double up the ground wires but I'm not certain. On this topic code says to do only what your panel's manufacturer says is ok.

I've heard the answer to that and I forget it, partly because Canadian and US codes are different on that question. Search other postings in this NG and you'll find it.

In general NM should be along the faces of joists and through holes, never across the undersides of them. At your ceiling-mounted light fixtures (octagonal boxes or recessed pot lights) you staple the NM to the nearest joist and then it can run to the box; there should be no need for armored cable unless your local code requires it (as I'm told Chicago, NYC and some others do).

You *might* get away with stapling the NM to boards that are fastened across the undersides of the joists; this is permitted in certain circumstances where you're sure there will never be drywall on the joists. I think it's the inspector's call.

I'm wondering how you'd do a dropped drywall ceiling. I guess you'd have to build a whole framework of joists at the height you wanted it. Of course you can never have any electrical junction box hidden insde a drywall ceiling; there are metal access panels you can build into the ceiling if you have to. If you plan to avoid junction boxes by making your connections in the pot lights, ie feeding one pot light from another, be aware that the little boxes on pot lights may be used as junction boxes only if they're marked as such. Some are, some aren't. I think it's a matter of how big they are.

Chip C Toronto

[hallerb]

use a suspended cieling for easy access for repairs.

can never understand anyone drywalling a basement cieling, even running a phone cable becomes a huge hassle

[Oscar_Lives]

Use a wireless phone.

[Tony Hwang]

Hi, Drywall may cost less and can give little extra ceiling height. My basement was poured to have standard 8 feet height when house was built. Basement was finished 100% by builder as well. Tony

[Bud--]

Long answer from another current thread: UL, as I understand it, in their standard for panels limits the number of 'poles' that can be installed in a panel. (a 220V breaker is 2 poles, a 12V breaker is 1 pole, a 120V tandem breaker is 2 poles.) The maximum number of poles in a 100A 120/240V panel is 20. (In a 200A panel 40.) If a panel has positions for 16 full sized poles it could have 4 more poles and stay under the 20 limit. These can be installed as 4 120V tandem breakers. To prevent more than 4 tandem breakers from being installed, a tandem breaker has a hook to install it on the panel rail instead of the normal SquareD U shaped clips. Only 4 positions on the rail can have a slot to accept the hook. These breakers are called class CTL (circuit limiting). (A 100A panel may be designed so fewer than 20 total poles can be installed.) Previous to the class CTL panels tandem breakers had the normal U shaped clip and could be installed in any position (or all the positions). Last I heard these non-CTL breakers were still available. As indicated in the quoted post, a panel on its label should have a list of breakers that can be installed in that panel. A class CTL panel will not have non-CTL breakers on the list and it is a code violation to install a breaker that is not on the list.

From aother current thread: NEC 2002: 408.21 allows only one neutral per lug. "Explicitly" is right.

Appears no. (NEC 210.23A)

bud--