GFCI Receptacles

[paul32]

Charlie,
If the code doesn't say the load to be served is from article 220 (which has the part for BRANCH circuits), then what is it? You seem to say it is anything you want. Well, if there is no equipment for the receptacle, then I guess to load is 0 and I can put all the receptacles in the building on one circuit. Do you really think that is what code says? Just because 210 doesn't specifically say "use article 220" I also don't think it says to use article 250 for grounding, but we have to follow it.

 

[charlie b]

If you start at the Index, you will see that if you want to know about grounding, you go to 250. Other articles also refer you back to 250. The Index also will tell you that if you want to know about calculations, go to 220, and if you want to know about branch circuits, go to 210. But one thing that does not show up is a statement in 210 that directs me to use 220.

My specific point is that 210 does not tell me that I ?must? go to 220, to get the value of the ?maximum load to be served.? I say again, in different words this time, if 210 doesn?t tell me I must, they why are you telling me that I must?

If you want to use 220 (and specifically, 180 VA per receptacle), I will not tell you that you are wrong. Indeed, I support that as a good way to do this design. But a design it is, and the NEC is not a design manual. If I choose to find another way to determine the ?maximum load to be served,? as is required in 210.19(A)(1), then you cannot tell me that 220 forbids me to do so.

 

[paul32]

The code does not say you can't have a larger value of the load, but it does say the minimum for the load. 210 does not have to refer you to 220, because part 2 of 220 is titled "Branch circuit load calculations". It says branch circuit loads SHALL BE calculated as 220.12, 220.14, and 220.16. Then 220.14 says the MINIMUM load for each outlet for general-use receptacles... SHALL NOT BE LESS than that calculated in 220.14(A) through (L).

Therefore if there is a commerical receptacle, the load has to be at least 180VA. The maximum load to be served by a branch circuit cannot be smaller than 180 times the number of receptacles.

 

[racerdave3]

Maybe somebody will know what I'm half remembering and be able to fill-in the specifics into the blanks. . A couple decades ago there was a manufacturer that limited the load plugs off of their GFCIs (they called them GFIs back then) to 4 load plugs.

Their concept probably was that they would sell more GFIs because of the limit. . For example, if you wanted to put 11 plugs along the kitchen counters you could only load 8 plugs off of the 2 GFIs and would be forced to buy a 3rd GFI for the 11th plug.

Anyway, what they found out was that contractors were switching to other brands that had higher load plug number limits. . So somebody in the company said, "Uh Oh !! . That didn't work out like we planned !" . I don't remember if that manufacturer increased their load plug count or just completely eliminated it.

David

This is intersting that the manufacturers will place a limit on the maximum number of receptacles that can be fed through the GFCI. Now for the most part this is a moot point as in 95% of the situations, the number will not be reached, but the bottom line is that if you have a 20 amp circuit that is protected from a GFCI receptacle that is rated for 20 amps, it should not matter how many outlets are downstream from it because the device can handle a load of 20 amps and if it is exceeded, the overcurrent device will trip anyway.

 

[charlie b]

Sorry, Paul. You are going to have to build your case without referring to Article 220, or in the alternative prove to me that 210 tells me to go to 220.

The title of 220 Part II does not matter to me, nor does the fact that 220 says what branch circuits shall be “calculated” as. When I read 210, I see the words, “the maximum load to be served.” I do not see the words, “the calculated load.” The loads “to be served” are the ones that I, the designer, choose to place on that circuit.

I am free to perform my design in any manner that does not conflict with the NEC. I can design a branch circuit to serve any load that I choose to put on that circuit, provided only that the rating of the branch circuit is not lower than the amount of load that I choose to serve with that circuit. Take another look at my earlier comment about my “mansion” (comment #13 in this thread). Tell my why I can’t place all 24 receptacle on one circuit, given that the total load to be served is 12 amps. And be sure, when you are telling my why I can’t do this, you refrain from mentioning anything in 220.

Perhaps I should directly address your earlier question:

If the code doesn't say the load to be served is from article 220 (which has the part for BRANCH circuits), then what is it?

Let’s be clear about the question. You could have meant, “What is 210,” or “What is 220.”

210 is about branch circuits, and it addresses such things as which ones need GFCI and which need AFCI, which specific circuits do you need in a dwelling unit, what rating must be used, what types (but not numbers) of receptacles can go on what rating of branch circuit, and what specific outlets are required in certain applications. Although it is not a design manual, it does provide criteria that must be met in the design.

220 is all about making sure the house (or other facility) has enough power to supply the loads that the code considers the minimum for a safe installation. You don’t have to build the house in accordance with the load calculated in 220. If for example the calculated load for a new house is 175 amps, then you will certainly need a service panel rated for at least 200 amps. But there is nothing that says to add up the loads after you have finished building the house, and if the amount you installed does not add up to 175 amps, you must go back and install more things until you get to the calculated minimum of 175 amps of load.

My point is that there is no connection between the design requirements of 210 and the calculation requirements of 220.

And that brings me back to the beginning: You are going to have to build your case without referring to Article 220, or in the alternative prove to me that 210 tells me to go to 220.

 

[dnem]

Sorry, Paul. You are going to have to build your case without referring to Article 220, or in the alternative prove to me that 210 tells me to go to 220.

90.3
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6 and 7 apply to special occupancies, special equipment, or other special conditions. . These latter chapters supplement or modify the general rules. . Chapters 1 through 4 apply except as amended by Chapters 5, 6, and 7 for the particulasr conditions.

Since 220 contains wording like "shall not be", you can't ignore it.

 

[dnem]

This is intersting that the manufacturers will place a limit on the maximum number of receptacles that can be fed through the GFCI. Now for the most part this is a moot point as in 95% of the situations, the number will not be reached,

You haven't seen the work of the contractors working in Medina County Ohio. . 95% or more of them set a GFCI in the basement and then it's "off to the races". . Over to the other side of the basement and up into the garage and around the whole outside perimeter of the house.

Then they set a GFCI in one of the bathrooms and it's off and running again. . First floor, second floor, basement baths all loaded off of one. . And you won't find the GFCI consistantly in any particular bathroom. . Whereever the other 12gauge circuit is needed, the bathroom plug circuit tags along in the 3wire HR. . The closest bath to that area gets the GFCI and every other bath plug in the whole house is loaded off of that one. . You might be in a house with a basement panel but the basement bath trips a GFCI two floors up on the second floor, and it could be back through the master suite back in the masterbath tucked back in the far side of the house.

David

 

[charlie b]

Since 220 contains wording like "shall not be," you can't ignore it.

I don't plan to ignore it. I just don't consider it relevant to the design of branch circuits. Perhaps I should say it does not mandate the design of branch circuits. I can choose the load that is "to be served" by a branch circuit, and 220 does not compel me to use 180 VA per receptacle as the one and only technical basis for my design.

 

[JohnE]

Charlie,

What about 210.11? (2002 as my '05 is elsewhere at this moment, but I imagine this has not changed) This seems to contradict your argument.

 

[charlie b]

What about 210.11? (2002 as my '05 is elsewhere at this moment, but I imagine this has not changed) This seems to contradict your argument.

It has changed, but not in any significant way (mostly due to new paragraph numbers). It does not contradict my argument.

But 210.11 says that I have to provide branch circuits, without telling me how to design them. It says I must provide circuits for the lighting loads, as computed in 220, and for appliance loads, as computed in 220. It does not say that I must provide circuits for receptacle loads, as computed in 220.

210.11 does go on to say that I must provide circuits for anything else required elsewhere in the code, without putting additional restrictions on how to design those circuits. So when I get to 210.19(A)(1), and I see that the branch circuit conductors must have an ampacity not less than “the maximum load to be served,” I do not feel obliged to turn to 220, as the only way to determine “the maximum load to be served.”

Let’s go back to my (purely hypothetical) mansion (comment #13). I discussed putting 20 receptacle outlets along walls, with one 60 watt floor lamp in each. I computed each receptacle outlet at 60 VA, not 180 VA, because I wanted to do so, and because I felt free to do so. Those receptacle outlets would not have been computed at 180 VA each anyway. They are not computed at all! They are part of the 3 watts per square foot allowance. Reference 220.3(B)(10) (2002 NEC) or 220.14(J) (2005 NEC)

 

[paul32]

Let?s go back to my (purely hypothetical) mansion (comment #13). I discussed putting 20 receptacle outlets along walls, with one 60 watt floor lamp in each. I computed each receptacle outlet at 60 VA, not 180 VA, because I wanted to do so, and because I felt free to do so. Those receptacle outlets would not have been computed at 180 VA each anyway. They are not computed at all! They are part of the 3 watts per square foot allowance. Reference 220.3(B)(10) (2002 NEC) or 220.14(J) (2005 NEC)

OK Charlie, so how does the 3 VA per square foot affect the layout of branch circuits?

Perhaps I should directly address your earlier question:

If the code doesn't say the load to be served is from article 220 (which has the part for BRANCH circuits), then what is it?

Let?s be clear about the question. You could have meant, "What is 210," or "What is 220."

The 'it' in my question was the load. If the load isn't specified by 220, then what is the load? I think you are saying it can be whatever you feel like.

 

[charlie b]

OK Charlie, so how does the 3 VA per square foot affect the layout of branch circuits?

It doesn?t. And it doesn?t have to.

For example, if the area is 1000 square feet, then I have to allow for 3000 VA for general lighting and receptacles. But that does not mean that I have to put in enough lighting fixtures and receptacles to add up to a total of 3000 VA. If I have the required outlets as specified elsewhere in the code, and if the outlets that come under the heading of ?general lighting and receptacles? add up to only 2000 VA, the Inspector cannot tell me to go back and put in some more lights.

But the Inspector can make me prove that the service size is big enough for the owner to add at least 1000 more VA in lights and plugs anytime in the future. 220 is about making sure the service can handle all 3000 VA (and a bunch of other stuff). 220 is not about the design of branch circuits.

If the load isn't specified by 220, then what is the load? I think you are saying it can be whatever you feel like.

Correct. I am saying the ?maximum load to be served? is whatever I design the maximum load to be. I may choose to design on the basis of 180 VA per receptacle, or I may choose to design on whatever other basis I wish.

 

[paul32]

It doesn?t. And it doesn?t have to.

For example, if the area is 1000 square feet, then I have to allow for 3000 VA for general lighting and receptacles. But that does not mean that I have to put in enough lighting fixtures and receptacles to add up to a total of 3000 VA. If I have the required outlets as specified elsewhere in the code, and if the outlets that come under the heading of ?general lighting and receptacles? add up to only 2000 VA, the Inspector cannot tell me to go back and put in some more lights.

That is true, and I agree, but not really the point. The point is you have a single 20A circuit that can handle 2000VA, but the inspector can make you put in two circuits for those lights and receptacles because their combined load is 3000 VA. Take a look at 210.11--that has the direct reference to 220.

The real difference between branch circuits and feeders/services is at the feeder/service level you can apply the demand factors. The loads come from 220 either way.

 

[charlie b]

The point is you have a single 20A circuit that can handle 2000VA, but the inspector can make you put in two circuits for those lights and receptacles because their combined load is 3000 VA.

What a circuit can handle and what you have installed on that circuit are two different questions. I can install two 20A circuits, so that I have capacity for just under 4000 VA of continuous load. Then I can install a total of 2000 VA of load between the two circuits (1000 VA each, so the load is balanced). I will have complied with the code, and in particular with 210.11. I will have provided branch circuits for the lighting loads calculated in 220. I just haven?t put in the lights.

The inspector cannot say that I am short by 1000 VA of lights. The inspector cannot use 220 to enforce 210. If there is a light, wherever the code calls for a light, and if there is a plug, wherever the code calls for a plug, and if the installed components fall of totaling 3 watts per square foot, that is not a violation.

Take a look at 210.11--that has the direct reference to 220.

Take a look at post #30 on page 3 of this thread. I have already addressed 210.11.

 

[dnem]

Correct. I am saying the ?maximum load to be served? is whatever I design the maximum load to be. I may choose to design on the basis of 180 VA per receptacle, or I may choose to design on whatever other basis I wish.[/SIZE][/FONT]

"I may choose to design on whatever other basis I wish."
That's not what the NEC says.

220.1 Scope.
This article provides requirements for calculating branch-circuit, feeder, and service loads. . Part 1 provides for general requirements for calculation methods. . Part 2 provides calculation methods for branch circuit loads. . Parts 3 and 4 provide calculation methods for feeders and services.

Part 3 for service calculations goes from 220.40 to 220.61. . So when someone quotes from a part of 220 that's not between 220.40 and 220.61, you can't claim that their post only applies to the service.

220.14 says, "shall not be less than"
220.14(A) says you use the actual load for outlets for specific loads.
"I am saying the ?maximum load to be served? is whatever I design the maximum load to be."
So if you know that maximum load, then 220.14(A) says your "requirements" (220.1) are to include that load. . It's not "whatever other basis I wish". . It's telling you what to do.

220.14(I) says 180va for non-specific loads except those covered by (J) and (K).
"I may choose to design on the basis of 180 VA per receptacle"
You use 180va when you don't know the load and I don't see the word "choose" in 220.14(I).

One more point.
The last sentence of 220.14(I) says, "This provision shall not be applicable to the receptacle outlets specified in 210.11(C)(1) and (C)(2).", which is dwelling small appliance and laundry restricted circuits. . If there are outlets to which this provision "shall not be applicable", then there are also outlets that it is applicable to. . Otherwise there would be no reason to specified certain outlets as not applicable.

David

 

[charlie b]

The last sentence of 220.14(I) says, "This provision shall not be applicable to the receptacle outlets specified in 210.11(C)(1) and (C)(2)."

That is because those two are given to us as 1500 VA per receptacle , so using 180 would not do.

But please take a look at the first sentence of 220.14(I). It winds up explicitly excluding the general lighting and receptacle circuits from being part of the “180 VA per receptacle” rule.

"I may choose to design on whatever other basis I wish."

That's not what the NEC says.

Then you go again, trying to build a case upon Article 220. I’m going to throw a flag on that play, for “Illegal Shift.” That’s a five yard penalty; we’ll replay the down. So now you have a “First and Fifteen.” What’s your next move? If you mention 220 again, you’ll be facing a “First and Twenty.” :grin:

 

[dnem]

But 210.11 says that I have to provide branch circuits, without telling me how to design them. It says I must provide circuits for the lighting loads, as computed in 220, and for appliance loads, as computed in 220. It does not say that I must provide circuits for receptacle loads, as computed in 220.

Those statements are only true if you ignore 210.11(A)

 

[dnem]

That is because those two are given to us as 1500 VA per receptacle , so using 180 would not do.

But please take a look at the first sentence of 220.14(I). It winds up explicitly excluding the general lighting and receptacle circuits from being part of the ?180 VA per receptacle? rule.

"It winds up explicitly excluding the general lighting and receptacle circuits"
Only excludes them in Dwelling Occupancies
This thread isn't about Dwelling Occupancies

 

[dnem]

Then you go again, trying to build a case upon Article 220. I?m going to throw a flag on that play, for ?Illegal Shift.? That?s a five yard penalty; we?ll replay the down. So now you have a ?First and Fifteen.? What?s your next move? If you mention 220 again, you?ll be facing a ?First and Twenty.? :grin:

I provided some proof after I said, "That's not what the NEC says."

It's convenient to ignore proof but doesn't help when trying to prove your point

That's not what the NEC says.

220.1 Scope.
This article provides requirements for calculating branch-circuit, feeder, and service loads. . Part 1 provides for general requirements for calculation methods. . Part 2 provides calculation methods for branch circuit loads. . Parts 3 and 4 provide calculation methods for feeders and services.

Part 3 for service calculations goes from 220.40 to 220.61. . So when someone quotes from a part of 220 that's not between 220.40 and 220.61, you can't claim that their post only applies to the service.

Ignoring it doesn't make it go away.

David

 

[charlie b]

I am not ignoring it. I am simiply not using the calculation process as the means of determining the actual, installed load (or the load that I plan to actually install).