How many receptacles on a circuit?

[5mall5nail5]

I am not sure if theres a regional rule, but how many receptacles can be on a 20A circuit (with 12/2 cable and 20A breaker)?

 

[Stuart in MN]

For residential use, the National Electric Code has no set limit on how many receptacles are on one circuit. There may be regional or state requirements.

Of course, you need to be realistic about it - no one is going to put 100 receptacles on a single circuit, and it also depends on the room and how they are going to be used.

 

[5mall5nail5]

This is what I am learning now after some research - no NEC code guiding the number of receptacles on a circuit.

This is in a garage where I want to run a 20A circuit (120v) using 12/2 and 20A receptacles. I picked up 2-gang boxes because I want to have 4 outlets at each drop given this is a workshop area. I am going to place a 2-gang box every 4 ft or so, so that I have 3 on each side of the garage for easy access. I am planning on putting the boxes about 46 - 48" up the wall so as to avoid hitting any of my workbenches/tools.

 

[sands35]

If you are going 46-48" up, why not go 49" to the bottom of the box? It will clear a sheet of plywood against the wall that way and still be under any wall cabinets.

 

[theoldwizard1]

I think code is minimum 48" from the floor, but I like the 49" recommendation.

 

[Charles (in GA)]

There are not code requirements for height of receptacles. As far as the number on a circuit, the only guidance the code gives is for non-residential, in many cases, it limits the circuits by using a formula of 180va per strap or yoke. For 120v/20 amp the circuit is capable of 2400va, divided by the 180va per strap/yoke, gives you 13 yokes or straps. This is so long as the yoke/strap has 3 or less receptacles on it. If you have four or more, the number changes to 90va per receptacle.

ARTICLE 100—DEFINITIONS

Receptacle. A receptacle is a contact device installed at the
outlet for the connection of an attachment plug. A single
receptacle is a single contact device with no other contact
device on the same yoke. A multiple receptacle is two or
more contact devices on the same yoke.

Charles

 

[5mall5nail5]

What is a strap or yoke

 

[wyliesdiesels]

I think code is minimum 48" from the floor, but I like the 49" recommendation.

Some of these things that u think are code(and are not) give me a chuckle! Thx for the laugh!

 

[zmaxmotorsports]

I think code is minimum 48" from the floor, but I like the 49" recommendation.

Ive put switches at 48" to top of box and plugs at 16" to bottem of box on most residential stuff for 30 plus years.
As far as plugs on a circuit for residential bedrooms/general purpose rooms Ive always tried to dedicate 1 circuit for the lighting and plugs of each room,kitchens and garages are a differant animal on the other hand.
If you have the room in your panel why not just use a seperate 20a circuit for each wall in garage for the tool circuits,you should never have a problem over loading it that way.
For the garage boxes you might want to try 48" to the top of plugs also to clear benches and stuff that get piled up.
Then run your lighting on a seperate 15a circuit.

 

[wkbdhvn]

When I built my last shop the best advice I got was to run to separate circuits to each 2-gang box so that the left side was one circuit and the right was another so that you could run two tools at once in one place and not trip the circuit.

 

[TheIceMan]

I have 4 boxes on each circuit (4 outlets at each box) with that size wire on each circuit. Boxes are every 6' apart.

 

[Joe G.]

When I built my last shop the best advice I got was to run to separate circuits to each 2-gang box so that the left side was one circuit and the right was another so that you could run two tools at once in one place and not trip the circuit.

I like that advice.

 

[Speedy Petey]

When I built my last shop the best advice I got was to run to separate circuits to each 2-gang box so that the left side was one circuit and the right was another so that you could run two tools at once in one place and not trip the circuit.

And if I may ask, how often do you take full advantage of this setup?

IMO it's a lot of extra work and/or expense for no real big benefit.

 

[stewed baker]

When I was doing residential wiring back in the dark ages we used 10 maximum receptacles [duplex/multiple receptacles] per circuit as a rule of thumb. Well under what was allowed/recommended per code.
The recommendation to use 2 circuits at every 2 gang box is very good.
Seems that no matter how well planned a garage and its electrical, there is a favorite spot in which to plug stuff or things show up that were not planned for.
With 2 circuits at every location there will be much less chance of tripping a breaker.
You don't neccessarily need 2 duplex receptacles in every location if you don't want.
2 circuits can be installed at a single duplex.
On the side of a duplex receptacle near the front and between the 2 receptacles, there is a metal tab that is designed to be removed by prying it back and forth. Break that tab, the one on the right, the brass colored one, the hot. DO NOT remove the white tab on the other side, the neutral.
Run 3 wire romex [12-3], connect the hots, black to the top and red to the bottom.
No extra cost, no extra work.
Any time you use 3 wire you have to use a 2 pole breaker to feed it.

 

[2ManyProjects]

When I built my last shop the best advice I got was to run to separate circuits to each 2-gang box so that the left side was one circuit and the right was another so that you could run two tools at once in one place and not trip the circuit.

And if I may ask, how often do you take full advantage of this setup?

IMO it's a lot of extra work and/or expense for no real big benefit.

You don't neccessarily need 2 duplex receptacles in every location if you don't want.
2 circuits can be installed at a single duplex.

While that certainly CAN be done, in the context of garages and workshops I prefer the approach described by "wkbdhvn", mostly for the reasons already explained in http://www.garagejournal.com/forum/showpost.php?p=3317565&postcount=14.