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Posted By: electure # of outlets by the point? - 01/06/03 01:13 AM
OK, I've got to confess...I was watching "This Old House" today.
They had an "electrician" that in addition to some incredibly bad work mentioned that outlets were computed by the "point", with a lighting outlet=1 point and a recp=2 points. [Linked Image] (A certain # of points could be put on a 15A circ, 20 A circ).
Huh?
Posted By: Electric Eagle Re: # of outlets by the point? - 01/06/03 03:06 AM
I didn't see the show, but I'll partially defend the guy. This is probably just his way of determining circuit capacity. Almost everybody I know uses different numbers for residential. Some go strictly by X number of openings, others will look at it with some grace given to outlets that you know won't be used and don't count them. How do you determine when to cut off a circuit, and don't tell me you calculate the actual load because you have no way to know what people will use them for and residential doesn't have the same restrictions that commercial does.

[This message has been edited by Electric Eagle (edited 01-05-2003).]
Posted By: ga.sparky56 Re: # of outlets by the point? - 01/06/03 03:33 AM
Eagle do you always have a plan with the electrical on it or do you lay most of it out yourself?
Posted By: Electric Eagle Re: # of outlets by the point? - 01/06/03 03:58 AM
Usually we have to lay it out ourselves. Even if we have prints, they don't break it down by circuit, just where they want the fixtures and switches.
Posted By: Sandro Re: # of outlets by the point? - 01/06/03 11:26 PM
Hrm... Canadian EC states that maximum 12 receptacles on a 15A circuit. I wonder how they agreed upon that figure? 1A per receptacle? 12A = 80%
Posted By: electure Re: # of outlets by the point? - 01/07/03 12:56 AM
Electric Eagle,
No need to defend the guy. I just haven't heard of such a "system", and wondered if you guys had. (I'm not trying to ruffle any feathers)
Some of the things the guy did on the show were undefendable.

How do you resi guys determine the number and distribution of your general-use recps./lighting outlets? (will we get 5 different answers from 5 different people?)
Posted By: sparky Re: # of outlets by the point? - 01/07/03 01:03 AM
AFCI's have some bearing in the layout here, since we are required to protect 'living areas', the definition has been 'interpeted' to death......
Posted By: Electric Eagle Re: # of outlets by the point? - 01/07/03 01:12 AM
electure,

We generally take 13 openings per circuit. But this is loosely defined, because like I said earlier some outlets we know will get rare use and other times you know a 400 watt fixture will be on the circuit. I guess we get the 13 figure from the maximum outlets allowed on a 20 amp commercial circuit. Also if I know 20 - 60 watt fixture are going to draw .5 amps each, I have no problem putting all on one circuit.

How do you determine circuits?
Posted By: ga.sparky56 Re: # of outlets by the point? - 01/07/03 01:30 AM
Eagles method approximates ours pretty close.Does anyone else use all 12?
Posted By: arseegee Re: # of outlets by the point? - 01/07/03 01:57 AM
For residential we put 8 to 10 recepts per 20A circuits. No lights on recept circuits. All lighting circuits are loaded to 1800 watts and we calculate the maximum fixture for the outlet. If its a bedroom we figure fan with 4 bulb light kit, 60 watt closet and so on.

I know we wire heavy but I picked up a contractor because his electrician had a long run of 12 with lights and recepts and when the home owner plugged in an iron the lights dimmed and flickered. That contractor spends about $150K a year with me now.
Posted By: electure Re: # of outlets by the point? - 01/07/03 01:58 AM
I do commercial/industrial work almost exclusively, (except some ultra custom homes) Any method I'd use for figuring residential would be non-competitive overkill at best [Linked Image] (but I'm always willing to learn)
Nearly everything here has the lights and recps run on different circuits, though.

In CA, our commercial lighting loads are limited by our energy laws. An office is generally only allowed 1.6 watts per square foot, so to use the NEC's figure wouldn't be practical.
Posted By: Ron F Re: # of outlets by the point? - 01/07/03 03:39 AM
I do alot of residential work, more often there are some sort of prints if there are a few trades involved. If not I will lay it out with input from the GC or the homeowner and have them sign off on it.
Ther are a few factors for determining the load or amount of outlets for each circut. If the house dose'nt have central a/c , I usualy install 20a dedicated lines for each bedroom, dining rm and living rm. Another If there going to use a bedroom for a home office. Taking alot of the load off the general use outlets. Most customers even with no knowledge of electrical can appreciate and grasp the idea of what your explaining to them. Taking the time and having a little patience with the customer before jumping into a job, makes the end of the job alot easier. Have'nt had a call back for a tripped breaker in 6 years
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