20 amp or 15 amp for common household receptacle use?

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LittleTree

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Hello all. Doing a complete remodel on an old historic home in Portland, OR and have garnered much info from this website in the past just by reading the forums. Well, the time has come to post my first thread. I am re-wiring all the electrical (as the homeowner of course) in this home and have gotten to the point of receptacles. I was going to run each room (take kitchen/baths/laundry out of the equation...understand the rules on those) separately on 20 amp circuits. That would mean 6, 20 amp circuits, 1 for each room. I spoke with an electrician friend and he said that was overkill and that I could run say 2 rooms each on one 20 amp circuit bringing me down to 3 or 4, 20 amp circuits. My question is, would it be acceptable or even better to run 15 amp circuits in each room instead? (back to 6 circuits but at 15 amps). It's seems to be a lot easier to work with and stuff 14-2 into a box than 12-2. All of this is just for common use of course. On top of that I will dedicate 20 amp circuits to computer/printer/TV/entertainment etc... centers. Would appreciate any info on this matter.
 

PatrickH

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So I would study up on the national electric code for branch circuits prior to pulling cable. The number of circuits required is not dependent upon the number of rooms you have. Basically you have to be able to reach an outlet within six feet anywhere along the wall line. Bigger rooms require more outlets. Breakers are limited to 80% loading of their capacity.
 

LittleTree

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So I would study up on the national electric code for branch circuits prior to pulling cable. The number of circuits required is not dependent upon the number of rooms you have. Basically you have to be able to reach an outlet within six feet anywhere along the wall line. Bigger rooms require more outlets. Breakers are limited to 80% loading of their capacity.
Thank you for the response. I have the code book and understand the spacing and the formula for the amount of circuits required per square footage. I don't think that's the issue I'm having. These are all "minimum" requirements. And actually, as I understand it, in residential homes you are allowed to use the full capacity of the circuit, which I am not doing. Commercial you are required to use the "safe load". I've calculated for the 80% safe capacity for all of my circuits.

Unfortunately the code book is not an instruction manual and I'm just wondering what an experienced electrician might do if he were wiring his own home for common use receptacles. Whether they would use 12 wag or 14 for common use. Does that make any sense or am I talking in circles? I know in spec houses a lot of builders follow the "minimum" rule and will stack 4 rooms on one 15 amp circuit. As this is my own home I'd rather have more than the minimum. Saying that, I know that bigger is not always better with electricity (learned directly from this site). Anyone? And thanks again in advance for any help.
 

PatrickH

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So use 180 volt amps per outlet. 10 outlets for a 15 amp circuit or 13 for a 20 amp circuit. This is slightly less than 80%. I don't imagine you have 13 outlets in each room do you? I use 12/2 for 20 amp circuits an 14/2 for 15 amp, so long as cable run is not too long for voltage drop. It's easier to wire outlets with 14/2 then 12/2, and you can put more conductors within the outlet box. Good luck!
 

Jadnashua

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It really depends on what your use patterns are. If you have, say an extensive stereo or movie system, you may want more than one circuit in a room. If you like to have a refreshments frig in your man cave, or have a bunch of computers (laser printers are much better than they used to be, but still have some pretty hefty momentary loads when the heater elements turn on). There is no one solution fits all. Personally, I like it when it's easy to turn off one room. I also like it if there are dedicated lights, that those might be separate from the receptacles, but that is probably overkill.
 

LittleTree

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So use 180 volt amps per outlet. 10 outlets for a 15 amp circuit or 13 for a 20 amp circuit. This is slightly less than 80%. I don't imagine you have 13 outlets in each room do you? I use 12/2 for 20 amp circuits an 14/2 for 15 amp, so long as cable run is not too long for voltage drop. It's easier to wire outlets with 14/2 then 12/2, and you can put more conductors within the outlet box. Good luck!
Great! That's what I was looking for. Thanks much.
 

LittleTree

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It really depends on what your use patterns are. If you have, say an extensive stereo or movie system, you may want more than one circuit in a room. If you like to have a refreshments frig in your man cave, or have a bunch of computers (laser printers are much better than they used to be, but still have some pretty hefty momentary loads when the heater elements turn on). There is no one solution fits all. Personally, I like it when it's easy to turn off one room. I also like it if there are dedicated lights, that those might be separate from the receptacles, but that is probably overkill.
Thank's for the reply. I did wire the lights separately from the receptacles but ganged a few rooms together to meet (or under) the 80% load of the circuit. I'm going to wire the tv/computer/stereo items to be dedicated so I don't run into tripping problems. And with the info PatrickH passed on I will wire 10 outlets per 15 amp circuit. I seriously enjoy the problem solving associated with electrical and plumbing work. Thanks.
 

Speedy Petey

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There is NO "80% rule" for household general use circuits. The 180va DOES NOT apply to residential general use circuits. This means there is no limit to the number of receptacles you can put on a circuit.
YES, common sense does apply and keeping to the limits shown is a good rule of thumb, but it is not code required.
 

LittleTree

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There is NO "80% rule" for household general use circuits. The 180va DOES NOT apply to residential general use circuits. This means there is no limit to the number of receptacles you can put on a circuit.
YES, common sense does apply and keeping to the limits shown is a good rule of thumb, but it is not code required.
That's what I thought. If you read my second post above I had stated that. However, in keeping with common sense, I am applying the "80% rule" to my project to avoid any nuisance tripping. Thanks for clearing that up.
 

DonL

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I would not use #14, just because "it is easier to work with" than #12, If #12 should be used, It needs to be used.

I like a easy job, but do not always get one.

You only get 1 Bullet. lol


Good Luck on your project.
 
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