Number of duplex recepticals?

Number of duplex recepticals?

  • Yes, Art. 220 limits the number of receptacles in commercial.

    Votes: 60 74.1%

  • No, there is no limit in commercial.

    Votes: 21 25.9%
  • Total voters
    81
  • Poll closed .
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dwellselectric

dwellselectric

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Location
Cape Cod, Massachusetts
Okay so my boss has been saying for 5 years now you can put as many duplex recepticals as you want on one circuit. I can not believe this I mean it just doesn't seem right. Isn't there a cut off number? I mean we never put more than 7 to 10 things on one circuit anyways but that has always bugged me that he keeps on saying that. Perhaps I am wrong wouldn't be a first but still....
 
There is no limit on the number of receptacles on a circuit. For calculation purposes in commercial application you would figure 180va per receptacle but that does not mean you cannot have more on the circuit. It is more of a design issue than a code issue.

I am sure others feel differently about it and it has been discussed on this forum many time.
 
stickboy1375 said:
In commercial you are limited to the amount of receptacles to a circuit, but in residential, in a nutshell you are unlimited...
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I don't believe that is accurate. I thought that was for calc. purposes only.
 
Dennis I strongly disagree that it is for 'calculation purposes only.

Can you show me a NEC section to back that idea up?
 
We've been through this before, Bob. Click on the link Dennis posted, to see the old discussions. But as a general summary statement of my view, can you show me where the NEC commands me to design circuits using 180 VA per receptacle? Please be sure that you do not cite article 220 in your answer. Branch circuits are described in 210, not 220.

Point in fact, I do choose to use 180 VA per receptacle as a design criterion. But I don't have to.
 
charlie b said:
can you show me where the NEC commands me to design circuits using 180 VA per receptacle? Please be sure that you do not cite article 220 in your answer. Branch circuits are described in 210, not 220.
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I will cite what I want.

IMO your view is odd considering the name and scope of Article 220.

'This Article provided requirements for calculating branch-circuit...'

I am not interested in another rehash all I will say is I disagree with your take on this, the folks at home can decide for themselves.
 
Point in fact, I do choose to use 180 VA per receptacle as a design criterion. But I don't have to.

Why would the NEC even make you calculate them at 180va if you could put as many on a circuit as you wish? It just does not make sense to me...
 
I believe most of us are smart enough to know the design issue with too many receptacles but think of this. If I had two 5' wiremold plug strip that were joined together and the receptacles were spaced at 6" apart, then I would need 2 circuits for that 10' plugmold. That doesn't sound right either.

In some cases those outlets are there for convience and don't have much load on them---
 
I agree with Bob and Stickboy, and so do the NECH authors. (I know the NECH commentary is just that, but it's nice to have the authors on our side)

Another issue to take into consideration is that all exams I have experience with also see it the same way.

Roger
 
Dennis Alwon said:
If I had two 5' wiremold plug strip that were joined together and the receptacles were spaced at 6" apart, then I would need 2 circuits for that 10' plugmold. That doesn't sound right either.
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It's not entirely right.

Have you looked at 220.14(H) which specifically covers that situation?

Depending on the conditions of use the code would count that 10' of wiremold as either 1200 VA {220.14(H)(1)} or as 3600 VA {220.14(H)(2)}

If the conditions of use required the 3600 VA figure it would be the appropriate time to order two circuit wiremold (It's a stocked item in large supply houses) and feed it with a MWBC
 
roger said:
I agree with Bob
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I was hoping you would post in here as you (Roger) is the one that straightened me out on this issue in the past.:)

I also felt there was no limit in either commercial or residential. Roger and others where able to demonstrate to me I was mistaken.


Another issue to take into consideration is that all exams I have experience with also see it the same way.
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That is a important point.

Even if Charlie and Dennis are correct, the inspectors, the testing providers, believe the NECH and other printed sources when they show a limit to receptacles.
 
iwire said:
'This Article provided requirements for calculating branch-circuit...'
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But it doesn't say anything about wiring and installing.

Without knowing the load intended for any receptacle, how do we know that 13 isn't too many for a circuit?
 
Hello Bob, I remember that earlier thread. :smile:

Bennie was even involved.

Roger
 
For anyone interested here is the commentary in the 2002 NECH I realize they can be wrong, in this case I think they are right.....they must be.....they agree with me. :grin: (JK)

To be fair this is also in the NECH.

The commentary and supplementary materials in this handbook are not a part of the Code and do not constitute Formal Interpretations of the NFPA (which can be obtained only through requests processed by the responsible technical committees in accordance with the published procedures of the NFPA). The commentary and supplementary materials, therefore, solely reflect the personal opinions of the editor or other contributors and do not necessarily represent the official position of the NFPA or its technical committees.
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2002 NECH said:
As illustrated in Exhibit 220.3, the 180-volt-ampere load is applied to single and multiple receptacles mounted on a single yoke or strap, and a 360-volt-ampere load is applied to each receptacle that consists of four receptacles. These are considered receptacle outlets, in accordance with 220.3(B)(9). The receptacle outlets are not the lighting outlets installed for general illumination or the small-appliance branch circuits, as indicated in 220.3(B)(10). The receptacle load for outlets for general illumination in one- and two-family and multifamily dwellings and in guest rooms of hotels and motels is included in Table 220.3(A). The load requirement for the small-appliance branch circuits is 1500 volt-amperes per circuit, as described in 220.16(A).


Exhibit220-3.JPG




Exhibit 220.3 The 180-volt-ampere load requirement of 220.3(B)(9) as applied to single- and multiple-receptacle outlets on single straps and the 360-volt-ampere load applied to each receptacle that consists of four receptacles.


Note in Exhibit 220.3 that the last outlet of the top circuit consists of two duplex receptacles on separate straps. That outlet is calculated at 360 volt-amperes because each duplex receptacle is on one yolk. The multiple receptacle supplied from the bottom circuit that comprises four or more receptacles is calculated at 90 volt-amperes per receptacle (4 ? 90 VA = 360 VA). For example, single-strap and multiple-receptacle devices are calculated as follows:

Device Computed Load
Duplex receptacle 180 VA
Triplex receptacle 180 VA
Double duplex receptacle 360 VA (180 ? 2)
Quad or four-plex-type receptacle 360 VA (90 ? 4)

A load of 180 volt-amperes is not required to be considered for outlets supplying recessed lighting fixtures, lighting outlets for general illumination, and small-appliance branch circuits. To apply the 180-volt-ampere requirement in those cases would be unrealistic, because it would unnecessarily restrict the number of lighting or receptacle outlets on branch circuits in dwelling units. See the note below Table 220.3(A) that references 220.3(B)(10). This note indicates that the 180-volt-ampere requirement does not apply to most receptacle outlets in dwellings.

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.
Exhibit220-4.JPG


Exhibit 220.4 Maximum number of outlets permitted on 15- and 20-ampere branch circuits.
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Now that view may be wrong but I bet that is the view held by the AHJ and inspectors in your area, I suggest if you plan on exceeding 13 duplex's on a 20 amp circuit that you ask the inspector first. :smile:
 
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