12 nm-b 20Amp Overkill in this situation

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  #1  
Old 12-13-10, 12:39 PM
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12 nm-b 20Amp Overkill in this situation

I Recently bought a home with a friend, he lives on the top floor and me on the bottom. The wiring in the house was functional, but scary, no grounds(it's an old house)and junction boxes galore. House has seperate service panels and completely seperate wiring for each floor.

My friend upstairs wants to ground the wiring out by connecting ground to neutral(he tried to explain it, but didn't do a very good job, im guessing a jumper from ground to neutral?), this idea scares me quite frankly. His dad did electrical work in the Navy for years, he said while this will work its not ideal and shouldnt be relied on. I convinced him that we can do a room by room re-wire and ground at the service panel because when we rewire we would be using nm-b with a ground.

My question is if I use 12/2 (12/3 in some instances) and install 20Amp breakers on all the breakers will this be overkill? I know that you can do some things with 14/2 and 15Amp breakers but I think it would give me peace of mind if I went with 12/2. The 20Amp breakers shouldn't be an issue because neither of us draws that much power.

So other than being more expensive, will doing everything with 12/2 be extreme overkill?

Thanks in advance for your opinions and advice.
 
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Old 12-13-10, 12:48 PM
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A 20 amp circuit will give you 1/3 more capacity for only slightly more cost. Many prefer 20 amp receptacle circuits as they are more versatile. Ligthing is typically good on a 15 amp circuit. Twenty amp circuits are required for the kitchen countertop, laundry, bathroom receptacles.

You friends idea of jumpering the neutral and ground together can have deadly consequences and is absolutely forbidden to be done. You could put current on any metallic portion of the system that is not designed to carry it.
 
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Old 12-13-10, 12:51 PM
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Originally Posted by InNeedofHeat View Post
My friend upstairs wants to ground the wiring out by connecting ground to neutral(he tried to explain it, but didn't do a very good job, im guessing a jumper from ground to neutral?), this idea scares me quite frankly.
This is called a bootleg ground, and it actually makes the circuit less safe than leaving the ground unconnected. The bootleg ground provides a path for someone to be shocked through the exposed metal cover of an appliance or tool plugged into that receptacle. Convince your friend not to do such a foolish thing.

I convinced him that we can do a room by room re-wire and ground at the service panel because when we rewire we would be using nm-b with a ground.
Complete rewire is certainly the best option. You can also leave the existing ungrounded circuits and add GFCI protection to make them safer, then install new grounded circuits where they are the most beneficial (kitchen, bath, laundry, entertainment) perhaps leaving some of the old circuits where they are not used frequently (table lamps, night light, etc).

My question is if I use 12/2 (12/3 in some instances) and install 20Amp breakers on all the breakers will this be overkill?
It's okay to do all #12 20A. Many people choose to install lighting with #14 15A circuits because the thinner wire is easier to work with in crowded multiple switch boxes, although it is not a requirement to do so.
 
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Old 12-13-10, 01:01 PM
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At this point I kind of want to do a complete re-wire. It will let me sleep more soundly knowing someone wont get electrocuted or my house wont catch on fire. I figure ill just go room by room and install the correct wiring, i'm pretty good with sheetrock so im not overly concerned about patching.

Also, this will allow me to start from scratch and split up any circuits in areas. For example, my kitchen only has one 20A circuit which powers two counter top outlets and a single two bulb overhead light. If im correct, i think the code requires two kitchen 20A outlets(GFI protected). I'm having a new service panel installed so i should have plenty of room to spread the circuits out.

Thanks guys.
 
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Old 12-13-10, 01:12 PM
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Originally Posted by InNeedofHeat View Post
If im correct, i think the code requires two kitchen 20A outlets(GFI protected).
The code does require two 20A small-appliance branch circuits serving kitchen, pantry and dining room receptacles. There are a few other requirements when doing a complete rewire specifically with the kitchen, bath, laundry and receptacle spacing in all other rooms. You will also need AFCI protection in most areas. I would recommend picking up a book about home wiring to make sure you don't miss details in such a big project. Wiring Simplified is a good, cheap option.
 
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Old 12-13-10, 01:17 PM
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Got one about two days ago and I'm about half way through it, it's nice, lays out all the wiring requirements for each room and shows you multiple ways of getting the same job accomplished. As far as AFCI is concerned, im planning on installing them in most areas, i figure while im doing it I should just do it right, after all it's just more money, and id rather spend more $$ up front than risk burning down the house haha.
 
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Old 12-13-10, 06:45 PM
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20a is not overkill. my whole house is wired with 12-2g and i have only tripped the outside breakers. also, since you are getting a panel upgrade, i would like to reccommend a Square D qo panel. i like Siemens, too. just stay away from GE, they are terrible. My house has one. i guess i think that because i grew up around qo's.
 
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Old 12-13-10, 07:49 PM
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My house is wired with 15 amp circuits and we rarely trip circuits. In fact, most homes that was wired by an electrical contractor will have only the code required 20 amp circuits wired in #12. Everything else will be #14/15amp circuits. The trick is to plan your circuits so they don't get overloaded. I would rather add more lightly loaded 15 amp circuits then install #12 wire (20 amp circuits) do to the fact it is much easier to work with and it is easy to keep wire counts down.

You did not mention how your place is wired. Is it in flex conduit? If this is the case your could pull in new THHN wires (with a ground wire) and save you an lot of grief.
 
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Old 12-14-10, 05:00 AM
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I wish it was run through conduit, gonna have to do a lot of snaking and cut n' patch work, but i'm pretty good with drywall so this isn't really a concern. In fact, it will allow me to re-wire things in the sequence i want and also give me more room to work with.

The thing im looking forward to the most is the larger box. Currently i have a 10 breaker pushmatic box, the new one will have 20 breakers, allowing me me much more space to break things up.
 
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Old 12-14-10, 07:33 AM
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Originally Posted by InNeedofHeat View Post
Currently i have a 10 breaker pushmatic box, the new one will have 20 breakers, allowing me me much more space to break things up.
Presuming it hasn't been installed yet, I'd highly recommend a panel with more slots - especially if you're planning a full rewire. For only a few extra dollars you can probably get a bit larger panel and never have to worry about it. Just the kitchen can easily chew up 4-8 circuits!
 
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Old 12-14-10, 09:48 AM
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Originally Posted by InNeedofHeat View Post
the new one will have 20 breakers, allowing me me much more space to break things up.
I agree with Zorfdt. Go with at least a 30 space / 40 circuit panel, or I prefer a 40 space / 40 circuit panel. It's very easy to go bigger now, not so much later.
 
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Old 12-14-10, 11:49 AM
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Originally Posted by Justin Smith View Post
20a is not overkill. my whole house is wired with 12-2g and i have only tripped the outside breakers. also, since you are getting a panel upgrade, i would like to reccommend a Square D qo panel. i like Siemens, too. just stay away from GE, they are terrible. My house has one. i guess i think that because i grew up around qo's.
My house has a GE main panel that appears to date from when the house was built in 1995. No problems with it at all.

If the top floor and main floor each have their own panel, I'd match them to allow for the same breakers to be used for both. I wouldn't get too caught up in brands beyond that.
 
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Old 12-14-10, 06:59 PM
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I prefer 20 amp circuts in case you plug in a heater or something. I use 12 awg even on 15a circuts. also, i have 20a hubbell backwire receptacles in my house, because i have alot of 20 amp extension cords.
 
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Old 12-14-10, 07:33 PM
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Originally Posted by caddymac View Post
My house has a GE main panel that appears to date from when the house was built in 1995. No problems with it at all.

If the top floor and main floor each have their own panel, I'd match them to allow for the same breakers to be used for both. I wouldn't get too caught up in brands beyond that.
Oddly enough GE is the only panels I don't like/recommend. That is except for GE bolt in panel boards.
 
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Old 12-14-10, 08:21 PM
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I am not big on any of the GE distribution boards (or washers and dryers for that matter). The trims, covers and doors don't fit quite right.
 
  #16  
Old 12-15-10, 05:29 AM
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Thanks guys, I think i'm going to go with a larger panel. Not sure of the brand yet, the electrician is coming over in a few days to check it out. Just an aside, how much should i expect to pay for this? The electricians a friend of a friend, but still, its good to have a ballpark so i know im not getting taken.

Just a service panel upgrade, no amp upgrade. Mains are seperate, so i guess it's a sub panel, but it contains all the breakers for the house.
 
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Old 12-15-10, 11:02 AM
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There are just too many variables with labor costs and site conditions to give any sort of price estimate.
 
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