Wiring half a house...

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Old 09-13-07, 07:47 AM
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Wiring half a house...

I have a 200 Amp breaker in an 1100 sq ft house. I need to wire:

1. four outlets in a upstairs bedroom
2. four outlets and four recessed lights in the living room below that bedroom
3. an exterior light and outlet (front door comes into living room)
4. in the basement below the living room, I need four outlets and 3 recessed lights in the finished section and a light and gfi in the unfinished section
5. in a room next to the living room, I need a ceiling fan/light and five outlets

Since breaker space is not really an issue, I was planning on putting:

1. everything in the basement on one circuit
2. everthing in the living room and the exterior light and outlet on one circuit
3. everthing in the room next to the living room on one circuit

2 questions

1. is there a better way to set this up?
2. I think I need a separate circuit for the four bedroom outlets because the other circuits each have five outlets and lights and eight outlets total is recommended for one circuit. I probably could go off of one of three circtuits listed above (probably the 5 outlet, fan/light), but is it better to just wire a separate circuit or would that be a waste?

Any suggestions regarding the three proposed circuits are welcomed along with what to do with the four outlets. Everything above is proposed 15 amp.

Thanks,

Jack
 
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Old 09-13-07, 08:03 AM
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Assuming the US, the bedroom needs to be AFCI. This means an AFCI breaker.

I think you need more circuits, and I think you should go with 20 amp circuits. 20 amp circuits only cost a little more, but provide one third more power per circuit.

I would put the lights downstairs (and the fan) on a separate circuit. Perhaps make that circuit 15 amp if you want.

Consider carefully what you will do in the living room and/or the finished basement. I recommend a dedicated circuit if you plan on using a computer. I recommend a dedicated circuit if you plan on a home theater setup.

I certainly recommend that you keep the outside receptacle and the unfinished basement receptacle(s) on separate circuits if you plan on high demand devices, such as power tools or the like.

Are you sure you are planning enough receptacles. Codes require them at certain separation, but more (ie closer together) is often better.
 
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Old 09-13-07, 08:38 AM
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I like your suggestions

It's a city row home, so the rooms are only 12'x12'. Basically I have one outlet on each wall, within 6' of each doorway or stairway and then in 6' increments. I would imagine that the front exterior outlet will be rarely used if ever, and the unfinished basement is only 5'8", so that outlet will also be used sparingly.


I think I will wire the the living room lights, other room ceiling fan/light, and exterior light together on a 15 amp circuit. The basement lights (finished and unfinished) on a 15 amp circuit.

I plan on using the finished basement as a bedroom so it should have an AFCI breaker as well. I'd imagine there will be a computer in each of the bedrooms in question as well as the theater system you spoke of. So, in regard to dedicated circuits...can I use a 20 amp circuit for the outlets in each room since the lights will be on separate 15 amp circuits? Or are you recommending a 20 amp circuit dedicated to the theater system, and two 20 amp circuits dedicated to where each computer will be set up?

Thanks again for your help.
 
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Old 09-13-07, 09:20 AM
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Consider your actual furniture placement or potential furniture placement when deciding where to place receptacles. For example, if a book case is going to be placed, you probably don't want it to block the only receptacle on the wall.

Modern computers use little power. But the peripherals are another story. Laser printer, in particular, are power hungry. Add to it routers, external card readers, USB hubs and yo very quickly can approach maxing out a circuit. You don't want someone to trip the breaker on you because the plugged in and turned on the vacuum cleaner while you were editing your (unsaved) masterpiece. Think about the total load on the circuit, and don;t ask for trouble. A bedroom on it;s own circuit is likely okay. But be wary of window air conditioners and space heaters...

Another factor is interference. Using a vacuum cleaner (or anything with a motor) sometimes causes interference on the circuit. You don't want that interference to mess with your television picture.


I hope your basement has the required two means of egress to have a bedroom. If not, don't use it as a bedroom or call it one.
 
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Old 09-13-07, 09:50 AM
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Agreed

I'm working on the window size right now...I believe some brick is going to have to be cut away to fit a big enough window. Right now the rough opening is 34"x34.5". I'm checking with a baltimore inspector to find the exact actual opening I need. Thanks for your help on the wiring layout/usage.
 
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Old 09-13-07, 11:09 AM
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I would definitely suggest keeping all of the lights seperate from the outlets. When you plug in motorized devices, such as a vaccuum cleaner, drill, air conditioner, ect. you get a voltage drop that causes an annoying dimming effect on the lights. Also the lighting loads are pretty much constant, so if circuited, wired, and operating correctly they shouldn't trip. Outlets are more likely to trip a breaker. When this happens, you won't be left standing in the dark if the breaker trips. The ouside light would be OK on an outlet circuit, and may required to be GFCI protected anyways (depending on if the light requires such).

I don't know if you've started any of the wiring yet, but I'd suggest going with 20 amps as well. Like racraft said, the slight offset in cost is worth the extra ampacity. Obviously 20 amps requires #12 copper wire, so if you've already wired with #14, the point is moot. I know that 15 amp circuits, along with putting lights on the same circuits are common residential construction practices. This minimizes cost, thus maximizing profit for the contractor. This practice is legal and is not unsafe, but it is not ideal for the homeowner. It's up to you to weigh cost VS quality.

To expand upon what racraft was saying about planning your # of outlets, the NEC (national electrical code) requires an outlet for evey 6' of wall space. This means no more than 6' from the end of a wall space and 12' between outlets. Wall space is any lenght of wall that measures 2' or more. The linear footage is measured around corners and excludes doorways, fire places, and like openings....

As for the number of outlets on a circuit, there's no set #. You just want to make sure that any continuous loads (loads being used for 3 hours or more at a time) does not exceed 80% of the circuit rating. For example, say you're planning out a 20 amp lighting circuit (lights are usually continuous loads except maybe closet lights or something of the like). You take the highest wattage the light's rated for, divide by the voltage (120 volts) and you get your current load. The total combined lighting load should be no more than 16 amps (80% of 20 amps). For general purpose outlets, unless specified for a device or appliance (fridge, microwave, stove, garbage disopsal, ect...) you don't have a specified load. I prefer to have 1 circuit per room for general use. Again, that's up to you to decide cost VS efficiency. If it helps any, according to atricle 210.14 (I), the NEC figures each general purpose outlet at a minimum load of 1.5 amps.

Keep in mind that electronic loads can be sensitive. That is why racraft suggests you plan dedicated circuits for your computer and entertainment center. You can put them on a general purpose circuit, but some loads may interfere with the electronics.

This might be overkill, but I have another tip for the lighting in the inhabited rooms. If you're installing all new electric, I'd use all fan rated boxes, run the lighting power feed to the switch boxes, run a 3-conductor w/ground to the lighting boxes, and use at least a double gang box for the light swithes. I say this so that you have the capability of installing a cieling fan in any of these rooms in the future. Even if you don't plan on installing ceiling fans now, it'll save you a lot of time and some cost in the future by planning ahead. The 3-wire will allow you seperate switching for the light and fan, or can be used to devide the lighting onto 2 switches in the future. I say to run the feed into the switch box, so that you can put in an outlet in the spare space of the double gang box if you're only using one switch. The outlet can later be removed to install an extra switch if needed.

One more good idea for you... If you're going to have the walls opened up anyways, and assuming you have access between the panel and an unfinished attic, I'd run an 1 1/2" PVC pipe as a chase. This will allow you to run additional circuits up to the 2nd floor with ease in the future. Just make sure to patch penetrations through floors and both ends of the pipe with fire putty or fire caulk.

In general this is how I'd circuit it:
1. interior lighting (assuming the total load is less than 80% of the breaker rating)
2. exterior light + outlet, unfinished basement outlet
3. living room outlets
4. bedroom outlets
5. finished basement outlets

If you put the entertainment center and computer on dedicated circuits, I might consider combining a couple the general purpose circuits. Combining the ouside outlet with the unfinished basement outlet isn't a big deal unless you plan on plugging in heavy loads into both at the same time. A tripped breaker from time-to-time is no big deal anyways. You just don't want to create a situation where you're tripping a breaker all the time.

I wish I could give you more advice on the AFCI protection. I know of the NEC requirement to have them, but my state's code (Wisconsin) over rules that one. Since we have no requirements to use them, I have no experience with them. I'm not sure how sensitive they are but I imagine that they can be a nuisance. I'd think that plugging in any appliance that's already turned on, such as a vaccuum cleaner, could cause it to trip. I would think putting in a bulb into a light that's swithed on would do the same. That is another reason to keep the lighting seperate from the outlets in my mind. I don't know if they make AFCI outlets that protect other outlets downline (like GFCI's do), but if they do I'd suggest going that route as opposed to an AFCI breaker. That way if it trips, you don't have to go all the way to the panel to reset it. In fact, I'd check to see if your area even requires AFCI protection.

Hope all this helps. I know my post was lenghty, so I hope it wasn't too confusing. Good luck!
 
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Old 09-13-07, 01:49 PM
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You should pick up some books that take you through the whole process. Wiring simplified is essential. I keep it in my electric bag for reference and to give me confidence when I'm just about ready to grab the main lugs in my load panel (kidding). I also like a book called "Wiring a House" that's part of the By Pros for Pros series.

I really like separating lighting from receptacles. It is one of those little things in "WaH" where he talks about doing things "Above Code". Another benefit is 14 gauge is so much easier to work with when you have multiple cables coming into a light box. And as said earlier, no voltage drop when appliances kick on.

I also like running 20 gauge so I can put those fat daddy receptacles in afterward and say, "you know what? you can run an air compressor non-stop in here and it won't trip."
 
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Old 09-13-07, 02:32 PM
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Originally Posted by brewcityc View Post

I don't know if you've started any of the wiring yet, but I'd suggest going with 20 amps as well. Like racraft said, the slight offset in cost is worth the extra ampacity.



As for the number of outlets on a circuit, there's no set #. You just want to make sure that any continuous loads (loads being used for 3 hours or more at a time) does not exceed 80% of the circuit rating...


Using 20 amp circuits IMO is a waste of money for residential,
all your gaining is 600 more watts per circuit, I would rather run two 15 amp circuits than one 20 amp circuit, but its all a design issue.

IMO the only thing required to be rated at a continuous load in residential would be a electric water heater or fixed electric heat, so don't be worried if you decide to use the maximum rating of a breaker...
 
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Old 09-13-07, 02:58 PM
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Originally Posted by Chris75 View Post
Using 20 amp circuits IMO is a waste of money for residential,
all your gaining is 600 more watts per circuit, I would rather run two 15 amp circuits than one 20 amp circuit, but its all a design issue.

IMO the only thing required to be rated at a continuous load in residential would be a electric water heater or fixed electric heat, so don't be worried if you decide to use the maximum rating of a breaker...


This would leave no room for expansion in most cases.

15 amp circuits can easily be overloaded fast. You plug in normal sized window A/C, and you probably maxed out that circuit already.
 
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Old 09-13-07, 03:58 PM
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Originally Posted by HotinOKC View Post
This would leave no room for expansion in most cases.
sure it would... so you would rather have one 20 amp circuit vs two 15 amp circuits? that makes no sense...

Originally Posted by HotinOKC View Post
15 amp circuits can easily be overloaded fast. You plug in normal sized window A/C, and you probably maxed out that circuit already.
This is why it is a DESIGN issue... like I said you would only be gaining 600 watts on a 20 amp circuit, I personally could not justify the cost of copper and labor for such little gain...
 
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Old 09-13-07, 04:14 PM
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I would rather have all 20 amp circuits for receptacles and 15for lighting, maybe even 20 for lighting. My current home is all 20 amp anyways, but that's just my opinion.

Plus, if you overload a 15 amp circuit, you then have to abondon that cable and pull all new 12gage for the 20amp costing more money then if you originally had all 20.

Having two 15's instead of a 20 takes up twice the space in the panel box too.
 
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Old 09-13-07, 05:29 PM
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Do the bedroom on 1 ckt. This way you only need 1 AFCI breaker.
 
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Old 09-13-07, 05:43 PM
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"Plus, if you overload a 15 amp circuit, you then have to abondon that cable and pull all new 12gage for the 20amp costing more money then if you originally had all 20."

Why abandon? Chances are one device/appliance put it over the edge. Just add.

Back to a design issue. Plan before you wire.
Chances are You know where the heavy draws will be.
Plan accordingly.

Your better off with a 20A light ckt. Bulbs draw more than unused receps.

I too feel that all 20A ckts "just because" is foolish.
And in no way do I feel that 14 is "easier to work with".

With the boxes sized correctly, and a neat and orderly install, They are both very easy to work with.
 
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Old 09-14-07, 04:03 PM
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[QUOTE=HotinOKC;1229237]I would rather have all 20 amp circuits for receptacles

.

QUOTE]

Can I ask why you really feel this is better? are you saying you think a bedroom or living room really requires a 20 amp circuit? Are you planning on putting a fridge in there or something?

Like I said before you are only getting 600 watts more, do you really think this makes all the difference? I'm not saying your wrong in your opinion, just curious how you got to think this way...
You like the word overload but I just can't imagine what your using to cause it to trip...
 
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Old 09-14-07, 04:12 PM
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I want to install 3 tanning beds and a whirlpool in my rooms!

I'm the type that always likes more power. I may never need it, but I like knowing it's there.
 
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Old 09-14-07, 04:15 PM
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Chris,

I am sitting in a bedroom of my house. I use it as an office. I have a dedicated 15 amp circuit for my computer system. It is NOT enough. Occasionally I trip the breaker when my laser printer kicks on. My UPS protects the computer from shutting down, but it sure is a pain to have to go to the basement ans reset the breaker. I sure wish that I had an extra 5 amps.
 
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Old 09-14-07, 04:45 PM
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Racraft,

If you need more power, We can help you with how to run a new dedicated 20A ckt for your equipment,Perhaps two.

With guidance, it realy is not too hard, or scary.

Just ask.
 
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Old 09-14-07, 04:58 PM
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Wow, I never thought of that! Maybe I should enlarge the circuit.

Actually, I solved the problem by moving some of the computer items over to the other circuit serving the room. But alas, that circuit serves several other rooms and is ungrounded, so I could only move the devices that had two prong cords.
 
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Old 09-14-07, 05:19 PM
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Originally Posted by racraft View Post
Wow, I never thought of that! Maybe I should enlarge the circuit.

do you want the copper wire enlarger ??

i have that gimzo lol anyway it pretty easy to run new 20 amp circuit because the computer load it get very tricky i know i did manged to trip the 20 amp circuits because i have 2 computers here 2 montiors , 15 inch TV , multiuseage printer / scanner plus a pretty powerfull flourscent/ metal halide lighting in here

Merci , Marc
 
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Old 09-14-07, 05:47 PM
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Originally Posted by HotinOKC View Post
I want to install 3 tanning beds and a whirlpool in my rooms!

I'm the type that always likes more power. I may never need it, but I like knowing it's there.
Thats cool and I liked you answer...
 
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Old 09-15-07, 11:10 PM
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OK bnymbill is probably scratching his head right now, if he hasn't just given up on this site. There are more than one way to skin a cat. It's all a matter of opinion. Apparently wire size is one that we experts can't agree on. Like I said before, it's a matter of cost VS quality. Maybe 20 amp circuits are overkill. Then again, maybe not. One could say running 2 15amp circuits as opposed to one 20 amp circuit is overkill. Now, instead of having a 2-wire homerun to the panel, you have at least a 3-wire homerun plus another breaker and one less breaker space available. The point is, however you want to do it, plan ahead. This also means take the future into account. Racraft's example of his bedroom turned into an office is a perfect example. Also window AC's and space heaters will draw a lot of current. You can do the minimum to get by, but it may cause problems in the future. If you go above and beyond your anticipated needs, it'll cost a little more now, but will save you time and money in the future if your needs change.
 
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