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Posted By: doc outlets on circuit - 10/17/05 12:44 AM
Well it has been a looooong time since I have been here and see the site and you guys are doing well.
I am in Texas just outside of Dallas . I am working for a large company and one of their test questions is
How many outlets can you put on a 15 amp circuit? I am talking recepts.
I need to settle an argument and my stance on it is that there is no limit to how many outlets you can put on a 15 amp circuit if you want to put a hundred on it you can but the load on that circuit can only be about 12 amps which is about 80 per cent .
If you had a 100 motors that only pulled 1/10 of an amp you could put all of them on one circuit.
The guy giving the test says that you can never put more than 6 outlets on a circuit and that this is an industrial standard.
I have never heard of such a standard and now there are 2 masters telling me the same thing . When I ask thenm to show me a code on this they say it is based on volt amps which as nothing to do with the number of outlets
So am I wrong here or am I just missing something for now they are saying I have answered the question wrong.


[This message has been edited by doc (edited 10-16-2005).]
Posted By: Ron Re: outlets on circuit - 10/17/05 12:56 AM
In a residence, you are correct. Outside of a residence neither of you are correct (not 6 or infinite). See 220.3(B)(9)

Non-dwelling: If loads are unknown, most determine 100% calc non-continuous load on a 15A circuit, or 10 receptacles. (15*120)/180 =10 recepts

[This message has been edited by Ron (edited 10-16-2005).]
Posted By: ShockMe77 Re: outlets on circuit - 10/17/05 02:13 AM
If you rate each outlet at 1.5 amps like it says in the book, the number of outlets on 1, 15 amp branch circuit should be no more than 8. That would equal 12 amps, or 80% of 15.
Posted By: doc Re: outlets on circuit - 10/17/05 07:07 PM
ok guys who is correct here ? Ron in your post you have the word "most" should that be " must " which is a complete different meaning . Just asking
Shock,are you saying that that I can only have 8 or is that all I can use at one time
Posted By: Roger Re: outlets on circuit - 10/17/05 08:00 PM
Doc, as Ron pointed to, see 220.3(9)&(10)

In a residential circuit per the NEC, as many receptacles as you want, IMO this is by design to try to provide the typical homeowner as many receptacles as needed with out extension cords all over the house. Just because there may be 20 receptacles on a circuit does not mean there will be any more of a load than if there were 10.

Now, in other than a Delling the 180 va per yoke comes to play.

Some local codes did limit the numbers to lower amounts, but that would be specified on the exam.

Roger
Posted By: gfretwell Re: outlets on circuit - 10/17/05 08:43 PM
I agree with the 180va in "other than dwelling" installations but where does the 80% come from?
It is 10 duplex receptacles on a 15, not 8.
Posted By: jw electric Re: outlets on circuit - 10/17/05 08:48 PM
In the 2005 cycle that will be
220.14
(I) Receptacle Outlets. Except as covered in 220.14(J) and (K), receptacle outlets shall be calculated at not less than 180 volt-amperes for each single or for each multiple receptacle on one yoke. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than 90 volt-amperes per receptacle. This provision shall not be applicable to the receptacle outlets specified in 210.11(C)(1) and (C)(2).
Posted By: doc Re: outlets on circuit - 10/18/05 12:40 AM
ok guys be patient with me as I have this wash tub pulled tight down on my head wire twisted around it and full of cement so I am still confused
Now I did not come up with this thought on my own it came from talking with three masters that have about 90 years experience between them
When talking about the 180 va amp and this code . I was told that you can add as many outlets as you want but are limited to only being able to use 10 at a time. In a lot of buildings no one knows what is going to be hooked up to what so this is a suggested method but does not mean you can't add more
I really thought this was a good topic to kick around
A place I worked at was done by a profess crew and there are as many as 15 - 16 recepts on a circuit and this was a new construction inside the city limits and passed both rough and finish inspections



[This message has been edited by doc (edited 10-17-2005).]

[This message has been edited by doc (edited 10-17-2005).]
Posted By: Ron Re: outlets on circuit - 10/18/05 01:43 AM
My calculation only included non-continuous load. Unless you know what will actually be connected to the receptacles (which generally you will not), there is no requirement to consider the loads continuous, hence not needing the 80% derating.
So (15*120)/180 =10 recepts for 15A circuit
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