Max number of recepts per circuit, part 2

[dnem]

I think I need a catchier title that's more in line with Hollywood type movie names.

How about Max2 ?

 

[dnem]

Our Ohio IAEI just had our meeting from May 1 ? 3 and I got a chance to talk to Jeff Sargent about the receptacles per circuit question. Jeff is the Handbook commentary writer for panel 2, so I got a chance to ask him about his commentary and also talk to other code article writers on the interaction of these sections.

This is a summary of the notes that I made afterwards.
Thru all of the years that I?ve been involved in the electrical trade, I?ve heard that residential receptacles are ?lighting? loads. This is not true. Receptacles are receptacles and lighting is lighting. The two are separate and only blur in places like 210.70(A)(1)X.
Knowing that helps understand some sections better.

210.11 states the basic lighting outlet rule, ?Branch circuits? ..... ?supply the loads calculated in accordance with 220.10.?
The last sentence of 210.11(B), ?circuits shall only be required to be installed to serve the connected load.?
All receptacles are part of the connected load and, unlike the nameplates of many fixed loads, receptacle loads are calculated.

220.10 covers loads listed in 220.12, 220.14, & 220.16.
220.12 covers most fixed hardwired general illumination outlets. It does not cover any receptacles. The load for fixed hardwired general illumination outlets is calculated from Table 220.12 which lists Dwelling Units as 3va per sq? [ which is 0.025a per sq? of 120v general lighting which is 600 sq? per 15a and 800 sq? per 20a ]. But this number does not apply to coverage for individual circuits but rather to the entire building taken from the outside dimensions of each floor of the building. Total minimum number of circuits is determined by total calculated load, 210.11(A). This is a fixed hardwired general illumination outlet calculation only. This does not directly apply to any receptacles.

220.14 Other Loads is where receptacle loads are found.
220.14(J) Dwelling Occupancies says, ?the outlets specified in (J)(1), (J)(2), and (J)(3) are included in the general lighting load calculations of 220.12. No additional load calculations shall be required for such outlets.? So altho receptacles are not ?lighting? loads, their load is included in the fixed hardwired general illumination outlet calculation.

220.14(J)(1) applies to general-use receptacles. There are three types of general-use receptacles in dwelling occupancies:
1) general-use general purpose which are those that are listed in 210.52(A) but not in 210.52(B).
2) general-use small appliance which are those that are listed in 210.52(A) and also listed in 210.52(B).
3) general-use bathroom receptacles which are covered by 210.52(D) & 210.11(C)(3).

220.14(J)(2) applies to receptacles on the outside, 210.52(E), and to those in the basement & garage, 210.52(G)

220.14(J)(3) applies to fixed hardwired general illumination outlets not already covered by 220.12. The last sentence of 220.12 excludes certain dwelling unit lighting outlets. These are picked up in 220.14(J)(3). They include porch &/or exterior egrees lighting, 210.70(A)(2)(b), garages, 210.70(A)(2)(a), and unfinished spaces used for equipment or storage, 210.70(A)(3).

220.14(A) applies to loads such as the furnace, 422.12.
220.14(A) or (I) applies to receptacles that include laundry receptacles, 210.11(C)(2), depending on whether the appliance load is known (A) or not known (I).

220.14(D) or (F) applies to house accent lighting.

I?ve tried to double check all of my references and I think I have everything correct and recorded as it was explained to me.

David

 

[LarryFine]

Well, everything he wrote.

So, what's the conclusion? Is or is not the quantity of receptacles on a circuit limited?

 

[dlhoule]

IMO No!

 

[dnem]

So, what's the conclusion? Is or is not the quantity of receptacles on a circuit limited?

Quantity of plugs per circuit ?
No, Unlimited
Quantity of circuits per square foot ?
Yes, limits on the minimum number

And the reasoning behind it is this.
Home owners don't make purchases based on the number of receptacles in their house. They don't look around the room and say, "We have three more receptacles in the room that don't have anything plugged into them, so let's go buy three more things."

Usually the exact opposite is true. They buy whatever they want and just plug in splitters and extension cords if there aren't enough receptacles for everything they've bought.

So the load in the house has nothing to do with the number of receptacles. The minimum receptacle spacing of 210.52(A)(1), 210.52(A)(2)(1), and 210.52(C)(1) is intended to limit extension cords, not establish load. If you add receptacles, that doesn't mean that you're adding load.

I've never met a person that has looked at an unused receptacle and said, "Hey there's a plug that I'm not using, let's buy another TV to plug in." They fill up their house with stuff according to the sq' size of the house.

General use receptacle load is covered by 220.14(J). If the code panel thinks that the usual modern home load is increasing because of the increase in electronics and other modern gadgets, they will make a change in 220.14(J) and/or make a change in Table220.12.

If you voluntarily increase the density of the receptacles within the same square footage beyond what is required in 210.52, you decrease the percentage of receptacles being used, but the load stays the same. An increased density decreases the chance of splitters or extension cords being used, which is a very good thing.

If the customer can increase the receptacle density and also afford to pay for more home runs and breakers, that's the best scenario. But if they increase the density without being able to afford more circuits, it's still better to have more plugs than to have more splitters & cords.

David

 

[iwire]

And the reasoning behind it is this.
Home owners don't make purchases based on the number of receptacles in their house. They don't look around the room and say, "We have three more receptacles in the room that don't have anything plugged into them, so let's go buy three more things."

Usually the exact opposite is true. They buy whatever they want and just plug in splitters and extension cords if there aren't enough receptacles for everything they've bought.

So the load in the house has nothing to do with the number of receptacles. The minimum receptacle spacing of 210.52(A)(1), 210.52(A)(2)(1), and 210.52(C)(1) is intended to limit extension cords, not establish load. If you add receptacles, that doesn't mean that you're adding load.

David that sounds familiar. 8)

By me in the 'other' receptacles per circuit thread.

Think of one single bedroom, say it's 12' x 15', the amount of 'stuff' people place in that room will be dependent on the size of the room not the number of outlets.

If I put in the code minimum outlets or line the walls with outlets every 6" the actual load will be the same. 8)

 

[dnem]

David that sounds familiar. 8)

By me in the 'other' receptacles per circuit thread.

Think of one single bedroom, say it's 12' x 15', the amount of 'stuff' people place in that room will be dependent on the size of the room not the number of outlets.

If I put in the code minimum outlets or line the walls with outlets every 6" the actual load will be the same. 8)

Did I disagree with you on that point in that thread ?
And don't answer by telling me to look back at the thread and find out because it has about 300 posts and I think I might want to eat supper and play with my kids instead of surf thru 300 posts

David
PS If I did disagree with you back then, I'll just blame it on prescription medication, just like the politicians do :wink:

 

[ryan_618]

Are we really discussing this again?

 

[iwire]

And don't answer by telling me to look back at the thread and find out because it has about 300 posts and I think I might want to eat supper and play with my kids instead of surf thru 300 posts

:lol:

Fair enough. :lol:

 

[iwire]

Are we really discussing this again?

I am not discussing it.

I am discussing discussing it. :lol:

 

[dnem]

Are we really discussing this again?

I am not discussing it.

I am discussing discussing it. :lol:

As long as our discussing of the discussing isn't disgusting, then I think we're all right :shock:

 

[izak]

ok since i wasnt here for it last time, let me pose this question.
220.14 (I) gives us a reference for what to calculate a receptacle at; 180 VA per yoke...

if you follow the 80 percent rule for loading of circuits,
one 20 amp circuit is 2400 VA @ 120 VAC
80% of 2400 VA is 1920 VA
1920 VA divided by 180 VA is 11 (10.66666666666666666)

that would be 11 'plugs' on one circuit

i looked at a 2005 code handbook about three months ago, and it showed that exact method for determining max recepts on a circ.

now, has this already been covered, and if so, disproven? because it seems to make sense to me

 

[jwelectric]

ok since i wasnt here for it last time, let me pose this question.
220.14 (I) gives us a reference for what to calculate a receptacle at; 180 VA per yoke...

if you follow the 80 percent rule for loading of circuits,
one 20 amp circuit is 2400 VA @ 120 VAC
80% of 2400 VA is 1920 VA
1920 VA divided by 180 VA is 11 (10.66666666666666666)

that would be 11 'plugs' on one circuit

i looked at a 2005 code handbook about three months ago, and it showed that exact method for determining max recepts on a circ.

now, has this already been covered, and if so, disproven? because it seems to make sense to me

It would depend on the type of installation such as commercial or residential. The section you posted has no bearing on the number of receptacles on a residential circuit.

 

[scott thompson]

Wow, this subject has gone into EXTRA INNINGS!!!

What happened to the original thread???
you know - the one of which this thread spawned from :roll: :lol:

Scott

***BTW***

To clarify the base project classification of this thread's discussion
(for those whom may not have seen the "Mother Thread", and may be corn-fused as to whaddaheck everyone is talking about),
here are the parameters of the topic:

• The subject "Base Classification" is Residential, more specific - a Single Family Dwelling,
  
• The relevant topic is in regards to "General Use Receptacles",
  
• The qweries are relevant to if limitations to either the number of outlets per circuit, total area served by a given circuit, or both of these aspects exist or not,
  
• If limitations exist, where are they referenced at,
  
• These Outlets & / or Circuits are not in the categories of "Required Circuits" or "Specific Circuits",
  
• These Outlets & / or Circuits would be the ones referenced by Table 220.3(A) under "Dwelling Units", and specified as "General Use Receptacles" , which their value - in Volt-Amps, is included with the General Lighting Load, for Load Calculations as applied to a Service & / or Feeders to Panelboards.

S.E.T.

 

[dnem]

ok since i wasnt here for it last time, let me pose this question.
220.14 (I) gives us a reference for what to calculate a receptacle at; 180 VA per yoke...

if you follow the 80 percent rule for loading of circuits,
one 20 amp circuit is 2400 VA @ 120 VAC
80% of 2400 VA is 1920 VA
1920 VA divided by 180 VA is 11 (10.66666666666666666)

that would be 11 'plugs' on one circuit

i looked at a 2005 code handbook about three months ago, and it showed that exact method for determining max recepts on a circ.

now, has this already been covered, and if so, disproven? because it seems to make sense to me

Izak,

I know it can be a bummer to read thru a long post, but in this case, I think you need to read thru the very first post in this thread and see if it clears up any questions. I tried to be very specific in that post.

If you don't understand or don't agree after reading it, then jump back into the conversation.

David

 

[LarryFine]

To paint a visual picture of the discussion, let's say there is a room that has 10 receptacles in it, and they're all on one circuit. So far, okay, right?

Now, let's sat the customer wants more receptacles, and this room ends up with 20 receptacles. Do we now need two circuits for this room?

I say no. Good idea, yes; required, no.

 

[dnem]

To paint a visual picture of the discussion, let's say there is a room that has 10 receptacles in it, and they're all on one circuit. So far, okay, right?

Now, let's sat the customer wants more receptacles, and this room ends up with 20 receptacles. Do we now need two circuits for this room?

I say no. Good idea, yes; required, no.

You're right.

How about an example of the minimum required for a whole house. To make the example as simple as possible, let's add one single local requirement that excludes 14 gauge 15 amp circuits. That leaves us with everything on 20a circuits.

One circuit for the furnace 422.12 calculated according to 220.14(A).
One circuit for the laundry 210.11(C)(2) & 210.52(F) calculated according to 220.14(I).
This base house has no accent lighting, so we have nothing for 220.14(D) or (F).

The only things left are fixed hardwired general illumination outlets 210.70(A) in each room calculated according to 220.12 and 220.14(J)(3).
And the receptacles of 220.14(J)(1)&(2).
One circuit for general-use bathroom receptacles 210.11(C)(3) & 210.52(D).
Two circuits for general-use small appliance receptacles 210.11(C)(1) & 210.52(B)&(C).
One circuit to pick up everything else, all of the hardwired lights 210.70(A), all of the general-use general purpose receptacles 210.52(A)&(H), and the rest of the general purpose receptacles 210.52(E)&(G).

So our total is:
One for the furnace.
One for the laundry.
One for bathroom plugs.
Two for small appliance.
One for everything else.
So this is a total of Six circuits.

Furnace is one outlet.
Laundry is one plug (gas dryer).
Bathroom is a couple of plugs.
Small appliance is installed to the minimum required by 210.52(A)(1), (A)(2)(1), & (C)(1).
Everything else circuit is installed to the minimum required by 210.52(A)(1), (A)(2)(1), (E), (G), & 210.70(A).

Is this code compliant ?

It depends on the size of the house.

You have four circuits of bathroom plugs, small appliance, & everything else that fall under 220.14(J) and therefore under Table220.12. The load of 3va per sq? covers 800 sq? for these 20a circuits. So these four circuits are good for 800 x 4 = 3200 square foot home.

If the house was 3201 square feet then you would have to add one more everything else circuit for a total of Seven circuits.

If the house was 4001 square feet then you would have to add two more everything else circuits for a total of Eight circuits.

If you fill up the house with 10 times the number of small appliance & general purpose receptacles as is required by 210.52(A)(1), (A)(2)(1), & (C)(1), nothing changes in this example.

David

 

[izak]

does anyone know where i can reference the NEC handbook online, so i can go look and see what it was that limited receps like i remember?

 

[iwire]

does anyone know where i can reference the NEC handbook online, so i can go look and see what it was that limited receps like i remember?

No, but I know what you are referring to and it only applies to non dwelling occupancies.

 

[peter d]

Dnem, try as you might, you aren't going to convince anyone here that you're correct. It's over, done, stick a fork in it.