Outlets Per Breaker

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rmatc4

Member
Is there a code limit on the number of outlets allowed per breaker? I know that the load planned on the breakers should not exceed the breaker capacity, but if you are in a planning phase not knowing exactly what the end user will do, what is a good rule of thumb?
 

physis

Senior Member
Re: Outlets Per Breaker

for commercial it's 180 va each.

For residential 220 defines a minimum for general purpose loads but doesn't really describe how it should be applied across the receptacles.
 

james wuebker

Senior Member
Location
Iowa
Re: Outlets Per Breaker

physis is correct. In Commercial and Industrial you can put 10 on a 15 amp breaker and 13 on a 20 amp breaker. Residential has no limits on the number you put in however, NEC does require a min. number of branch circuits(220-4(a), and the receptacle and lighting loads must be evenly distributed among the required circuits (220-4(d). Also check with your local building/electrical code. Some local areas have a max. number of receptacles allowed.
Bye now,
Jim
 

benaround

Senior Member
Location
Arizona
Re: Outlets Per Breaker

Where in NEC does it limit how many recpts. on a circuit? Not the 180va used in computing load calcs.? Or the 1va per sq./ft. tbl.230.3(A).

frank
 

physis

Senior Member
Re: Outlets Per Breaker

It's 220.3(B)(9).

Edit: I think 220.4 enforces the calculated load doesn't exceed the branch circuit rating.

If that doesn't do it, it's somewhere in 210 or 220.

[ May 03, 2005, 10:24 PM: Message edited by: physis ]
 

bigjohn67

Senior Member
Re: Outlets Per Breaker

There is nothing in the code that says a specific number of outlets to a circuit. However, per load

20 amp x 120 v= 2400w
You can load a circuit up to 80%= 1920w
180w per yoke = 11 devices. we stretch it to 15 openings

But there is no where in the code does it state a specific # of outlets per circuit.
 

physis

Senior Member
Re: Outlets Per Breaker

I found it. It's 210.11 that enforces the calculated load be fed by branch circuits rated for it.

It doesn't say how many receptacles in English. It says it in math though.

CMP 2 wrote both articles 210 and 220. That's why it's difficult.
 

physis

Senior Member
Re: Outlets Per Breaker

I don't condone the writing style of CMP 2. I didn't do it. :D

But 220.13 has no effect on the application of 210.11

Edit: 220.13 is for load calculation and 210.11 is for providing branch circuits.

Edit again: I didn't put that right.

220.13 does impact the application of 210.11 in that the branchs circuits have to be rated for the loads calculated.

[ May 03, 2005, 11:06 PM: Message edited by: physis ]
 

dillon3c

Senior Member
Re: Outlets Per Breaker

210.23-permissible loads- 2005NEC
In no case shall the load exceed the branch circuit rating*.

210.23(a)Cord-and-plug-connected equipment not fasten in place.

Quote:The rating of any -"ONE"-cord and plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch circuit rating.

So we are rating the dwelling MULTIBLE receptacle circuit, at just at 80% percent? Granted, we don't know what going to be plugged into any one receptacle on the circuit,but it doesn't say whole circuit with devices, must be rated not to exceed at 80%percent either..-again 210.23-you can max the circuit out with receptacle devices,for (dwelling units).

show me where it can't be done.

[ May 03, 2005, 11:22 PM: Message edited by: dillon3c ]
 

benaround

Senior Member
Location
Arizona
Re: Outlets Per Breaker

physis,

Branch circuits,art.210.11, provides the circuits to the loads computed in 22o.3 more so 220.3(b)(9), which is the 180va per duplex recpt. you use to figure load calcs.
I asked to explain 220.13, because it states that if you use the 180va computation you are allowed to add it to the lighting load and then use demand factors! The first 10000va at 100% over that only 50%, so now I can put 20 duplex on a 15a and 26 on a 20a c.b. Physis, I'm only doing this because you hear it all the time "You can only put ?# of recpts. on a circuit". It's not code,It's misunderstood.

frank
 

physis

Senior Member
Re: Outlets Per Breaker

It's funny you mention that Dillon.

In no case shall the load exceed the branch circuit rating
Iv'e found that or something closely related to that sentance just plain strewn about article 210 during some of my expeditions.

I wonder if CMP 2 is trying to make a point?

In my opinion it's truely helarious how, instead of being concise, CMP 2 chose to be, well, sloppy about it.
 

physis

Senior Member
Re: Outlets Per Breaker

Frank is right about what?

I just don't know which point you're refering to.

Edit: There's a new post I haven't seen yet from Frank. Give me a chance to read it.

I've been having technical problems with the site for a while now. Sorry.

[ May 03, 2005, 11:55 PM: Message edited by: physis ]
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Re: Outlets Per Breaker

If anyone has the 2005 NEC Handbook, on page 106 in exhibit 220.4 it states that the maximum number of permitted outlets on a 15 amp circuit is 10 and the maximum on a 20 amp circuit is 13. An outlet is defined in this exhibit as a single, duplex or triplex receptacle on one yoke.
 

dillon3c

Senior Member
Re: Outlets Per Breaker

infinity,
Its not reflected in the '05 handbook CD,let me dig the hardbook out..
 

physis

Senior Member
Re: Outlets Per Breaker

Ok, I think I see the point.

We're talking about two different things here.

220.13 is allowing a demand factor to be applied for service load calculation.

But it doesn't change the "required" load that has to be provided for by the branch circuit.

It's a good a point. And I'm not familiar with 220.13. I think I've got it right but if you disagree I'll look at it some more with you guys.

[ May 04, 2005, 12:04 AM: Message edited by: physis ]
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: Outlets Per Breaker

Infinity,

Please note the text in the '05 Handbook, immediately before Exhibit 220.4 states:
In Exhibit 220.4, the maximum number of outlets permitted on 15- and 20-ampere branch circuits is 10 and 13 outlets, respectively. This restriction does not apply to outlets connected to general lighting or small-appliance branch circuits in dwelling units.
The bold - italics is my emphasis.
 

physis

Senior Member
Re: Outlets Per Breaker

Evening Al, Where are you at in our great nation? I don't see you out this late much.

[ May 04, 2005, 12:09 AM: Message edited by: physis ]
 

dillon3c

Senior Member
Re: Outlets Per Breaker

Well in 220,(dwelling)general purpose branch is reflected in the 3va per square foot. For general purpose BC,(dwelling)no VA requirement, receptacle device(not for General purpose Branch)

infinity,care to elaborate further in page#106,Exhibit 220.4 of handbook?
 
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