Wall Receptacles distance/coverage/quantity rule

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tk3000

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Above is a simplified sketch of a layout of a f small bedroom. The 3D box at the lower level are outlet/receptacles, the one 3d box at the upper level near a door is a light switch (which currently does not exist). Two of the walls of this room face the exterior (concrete walls) as labeled. One side of the wall has 141” and the other side 86.5”

Currently there is not light switch on wall or light fixture on ceiling. The only outlets present are outlet3 and outlet5, which currently should not meet code as far as outlet distribution and no of outlets is concerned. The other outlets are planned to be installed and light switch are planned to be installed.

I understand that the 6' rule dictates that receptacles can not be more than 6 feet apart in both directions (hence, no more than 12' space should lack a receptacle) , based on that rule my sketch would meet code.

But, then, there is this pesky other rule that seems to conflict with the 6' rule, the following: 'wall space 2' or more in width will require an electrical recepticle. So, does that mean the 86.5” wall (exterior wall) [note that sketch labels it as 58.5", but it is 86.5"] which lack any receptacle but have two receptacles on the two walls perpendicular to it which then implies that the there is not point on the this wall that would be more than 6' feet far from a receptacle; but then that wall still would be an over 2' width wall without a receptacle present
 
First of all by code for a light when entering a room. A switch must be provided so that a ceiling light or switched receptacle (to turn on a floor lamp) must be present. If there are more than one entrances/exits of the room 3 way switching must be provided to eliminate the need to walk through a dark room to turn on the light (which is common sense).

As far as receptacle spacing. You almost have it correct and that is why you are confused. Spacing of receptacles are to be no more than 12 feet from one another not 6 feet from one another. The reason here is (as the NEC puts it) is most devices such as floor lamps, vacuum cleaners, etc have cords that are about 6 feet long and by putting the receptacles no more than 12 feet apart gives you the ability to plug in a floor lamp as example without having to use an extension cord which may cause a trip hazard.

The 6 foot rules is spacing from any doorway. A receptacle must be placed within 6 feet from either side of a doorway. A receptacle must also be placed in any wall space of 24 inches or more (example, the wall space between two doorways etc). Note: even if a wall space (24 inche) exists between the 12 foot rule the receptacle between the doorways must still be placed there (between the two for the 12 foot rule).

When I plan on the wiring of a room I figure my 6 foot rule first, mark the studs where the boxes will go and then measure for the 12 foot rule from there. Once you have figured that out then you can add more if you want for convenience.

However, there is a limit as to how many receptacles you can place on a circuit.

Usually standard duplex receptacles are rated at 180 watts each.
My calculations that I normally perform are as follows:
If using a 20 amp circuit (of course then using 12/2 with ground)
120v x 20 amp = 2,400 watts x 80% = 1,920 watts
1,920 watts divided by 180 watts (per receptacle) = 10.66 receptacles allowed on circuit.
If using a 15 amp circuit you would use 14/2 w/ground and in calculation substitute the 20amp with 15 amp.

I normally don't put the max allowed on a circuit as with todays power consuming devices it is more convenient (costs a bit more in wire) to give them more circuits to cut down on the times a circuit is overloaded and the breaker trips due to this fact.

Also, when I wire a house, I don't limit a circuit to one room only. I try and alternate my circuits in one room. What I mean by this is if I put a circuit in a room for the receptacles and lights and in the future there is an issue with that circuit for whatever reason (bad receptacle etc) the home owner does not loss power in the entire room and has to run extension cords from other rooms, through hallways etc causing a trip hazard.

Also it give them the ability to run more in that particular room. I limit the number of receptacles according to the home owner's request after I go through with them what I just explained here. There is the issue also though the more circuits you add the more wire you use and with the new codes the more AFCI breakers you need which are more expensive than regular breakers.
 
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The rule is that no spot may be more than 6 feet from a receptacle. The first one beside a door must be within 6 feet because you can't can't count the space crossing a door. Then they can be up to 12 feet apart because if you put put something in the middle between them you will be 6 feet from a receptacle.
Also any wall space 2 feet or larger must have a receptacle.
You can put them closer if you want. Those distances are maximums.
 
First of all by code for a light when entering a room. A switch must be provided so that a ceiling light or switched receptacle (to turn on a floor lamp) must be present. If there are more than one entrances/exits of the room 3 way switching must be provided to eliminate the need to walk through a dark room to turn on the light (which is common sense).

As far as receptacle spacing. You almost have it correct and that is why you are confused. Spacing of receptacles are to be no more than 12 feet from one another not 6 feet from one another. The reason here is (as the NEC puts it) is most devices such as floor lamps, vacuum cleaners, etc have cords that are about 6 feet long and by putting the receptacles no more than 12 feet apart gives you the ability to plug in a floor lamp as example without having to use an extension cord which may cause a trip hazard.

The 6 foot rules is spacing from any doorway. A receptacle must be placed within 6 feet from either side of a doorway. A receptacle must also be placed in any wall space of 24 inches or more (example, the wall space between two doorways etc). Note: even if a wall space (24 inche) exists between the 12 foot rule the receptacle between the doorways must still be placed there (between the two for the 12 foot rule).

When I plan on the wiring of a room I figure my 6 foot rule first, mark the studs where the boxes will go and then measure for the 12 foot rule from there. Once you have figured that out then you can add more if you want for convenience.

However, there is a limit as to how many receptacles you can place on a circuit.

Usually standard duplex receptacles are rated at 180 watts each.
My calculations that I normally perform are as follows:
If using a 20 amp circuit (of course then using 12/2 with ground)
120v x 20 amp = 2,400 watts x 80% = 1,920 watts
1,920 watts divided by 180 watts (per receptacle) = 10.66 receptacles allowed on circuit.
If using a 15 amp circuit you would use 14/2 w/ground and in calculation substitute the 20amp with 15 amp.

I normally don't put the max allowed on a circuit as with todays power consuming devices it is more convenient (costs a bit more in wire) to give them more circuits to cut down on the times a circuit is overloaded and the breaker trips due to this fact.

Also, when I wire a house, I don't limit a circuit to one room only. I try and alternate my circuits in one room. What I mean by this is if I put a circuit in a room for the receptacles and lights and in the future there is an issue with that circuit for whatever reason (bad receptacle etc) the home owner does not loss power in the entire room and has to run extension cords from other rooms, through hallways etc causing a trip hazard.

Also it give them the ability to run more in that particular room. I limit the number of receptacles according to the home owner's request after I go through with them what I just explained here. There is the issue also though the more circuits you add the more wire you use and with the new codes the more AFCI breakers you need which are more expensive than regular breakers.

Thanks for the thorough response. The two light switches should not be a problem but the doors are very close to each other (about 2ft apart or less): one door giver access to the room (bedroom) from the hallway, the other door simply connect this room to another room. So, two light switches wired as a 3-way switch is required in this case despite the close proximity of the doors/entries?

“Spacing of receptacles are to be no more than 12 feet from one another not 6 feet from one another “ I guess I got the idea, but then there should not be any horizontal wall space without an receptacle within 6' distance or less. So, if two receptacles are 12' apart there would be no horizontal wall space between the two receptacles without an outlet within 6' range.

I can only imagine that the 2f' width wall rule needing a receptacles is some sort of isolated wall (not connected to other walls, like the wall between two door ways as you pointed out). And that a wall connected to another wall through a corner is considered the continuation of the same wall and thus the 6' rule applies.

“1,920 watts divided by 180 watts (per receptacle) = 10.66 receptacles allowed on circuit.
If using a 15 amp circuit you would use 14/2 w/ground and in calculation substitute the 20amp with 15 amp. “

Would a light switch count as receptacles as well assuming the light switch is connected to the same branch circuit as the outlets? Also, I would imagine that a 3way switch would count as one receptacle too. Besides modern led lights consume a fraction of the previous incandescent light for the same amount of lumens.

The city where I live follow NEC 2011 without exception. Does that mean that one would need AFCI breakers for almost every branch circuit? And all the 20amp breakers that came along with the panel will wasted… Or maybe simply installing an AFCI outlet (usually cheaper than an AFCI breaker) upstream from the other outlets without a necessary afci at the breaker panel itself.
 
The rule is that no spot may be more than 6 feet from a receptacle. The first one beside a door must be within 6 feet because you can't can't count the space crossing a door. Then they can be up to 12 feet apart because if you put put something in the middle between them you will be 6 feet from a receptacle.
Also any wall space 2 feet or larger must have a receptacle.
You can put them closer if you want. Those distances are maximums.

By wallspace 2 feet or larger, you mean a wallspace not connected to other wall?
 
“1,920 watts divided by 180 watts (per receptacle) = 10.66 receptacles allowed on circuit.
If using a 15 amp circuit you would use 14/2 w/ground and in calculation substitute the 20amp with 15 amp. “

Would a light switch count as receptacles as well assuming the light switch is connected to the same branch circuit as the outlets? Also, I would imagine that a 3way switch would count as one receptacle too. Besides modern led lights consume a fraction of the previous incandescent light for the same amount of lumens.
No, you do not count a light switch, but what you do count on the circuit is what the total watts are for the bulbs in the light fixture/s being used in the circuit (count the number of bulbs being used and total up their watts per bulb).

By wallspace 2 feet or larger, you mean a wallspace not connected to other wall?
Any wall space of 2 feet or more requires a receptacle.

Yes, even then.

When measuring the distance from one receptacle to the next for the 12 foot rule you go according to linear feet from receptacle to receptacle not direct line from one to the next in the way of a corner wall. Imagine a triangle with only two of the three sides. The two sides are the wall linear measurement, this is the measurement you must use. If you connect the triangle with the third line that is the line of site measurement. That may be less than the linear which will not pass.

The city where I live follow NEC 2011 without exception. Does that mean that one would need AFCI breakers for almost every branch circuit? And all the 20amp breakers that came along with the panel will wasted… Or maybe simply installing an AFCI outlet (usually cheaper than an AFCI breaker) upstream from the other outlets without a necessary afci at the breaker panel itself.
No, you can not use an AFCI receptacle as the first receptacle protecting down line receptacles unless you follow the NEC rules (see below and don't fall asleep reading it). Long story short in order to use an AFCI receptacle you must use MC from the panel to the first receptacle then house the receptacle in a metal box etc; yada yada yada. In the long run it is usually cheaper just to use the AFCI breaker. NOTE: It must be a CAFCI breaker. (C.ombination A.rch F.ault C.ircuit I.nterrupter). A mistake that many people make when reading this is thinking combination means AFCI and GFCI protection. Although there are such breakers what this rule refers to as "combination" is that the AFCI breaker protects both series and parallel arch faults. So yes, the extra breakers included with the purchase of the panel are basically useless except for just a few rooms in the house, like the basement and I think a utility room at this point.

So, two light switches wired as a 3-way switch is required in this case despite the close proximity of the doors/entries?

What I normally use as a rule of thumb which has not failed me yet is if I walk into a room and a light switch is within my arms (both arms stretched out in a line from doorway to doorway) reach then no 3 way switch is needed. Hope you got that.

210.12
AFCI receptacle instead of AFCI breaker can be used if:
(4) A listed outlet branch-circuit type arc-fault circuit interrupter
installed at the first outlet on the branch circuit
in combination with a listed branch-circuit over current
protective device where all of the following conditions
are met:
a. The branch-circuit wiring shall be continuous from the
branch-circuit over current device to the outlet branch circuit
arc-fault circuit interrupter.
b. The maximum length of the branch-circuit wiring from
the branch-circuit over current device to the first outlet
shall not exceed 15.2 m (50 ft) for a 14 AWG conductor
or 21.3 m (70 ft) for a 12 AWG conductor.
c. The first outlet box in the branch circuit shall be marked
to indicate that it is the first outlet of the circuit.
d. The combination of the branch-circuit over current
device and outlet branch-circuit AFCI shall be
identified as meeting the requirements for a system
combination–type AFCI and shall be listed as such.
(5) If RMC, IMC, EMT, Type MC, or steel-armored Type AC
cables meeting the requirements of 250.118, metal wireways,
metal auxiliary gutters, and metal outlet and junction
boxes are installed for the portion of the branch circuit
between the branch-circuit over current device and the first
outlet, it shall be permitted to install a listed outlet branch circuit
type AFCI at the first outlet to provide protection
for the remaining portion of the branch circuit.
(6) Where a listed metal or nonmetallic conduit or tubing or
Type MC cable is encased in not less than 50 mm (2 in.)
of concrete for the portion of the branch circuit between
the branch-circuit over current device and the first outlet,
it shall be permitted to install a listed outlet branch-circuit
type AFCI at the first outlet to provide protection for the
remaining portion of the branch circuit.
 
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By wallspace 2 feet or larger, you mean a wallspace not connected to other wall?
Correct. An example would be a short wall between two doors. Wall space continues around corners if not blocked by a door or other obstacle like a full height bookcase or fireplace.
 
No, you do not count a light switch, but what you do count on the circuit is what the total watts are for the bulbs in the light fixture/s being used in the circuit (count the number of bulbs being used and total up their watts per bulb).

Yeah, I realize that. Usually I employ the 80% rule which dimensions each branch circuit for 80% of its capacity.

When measuring the distance from one receptacle to the next for the 12 foot rule you go according to linear feet from receptacle to receptacle not direct line from one to the next in the way of a corner wall. Imagine a triangle with only two of the three sides. The two sides are the wall linear measurement, this is the measurement you must use. If you connect the triangle with the third line that is the line of site measurement. That may be less than the linear which will not pass.

Hmmm... That is a good representation

No, you can not use an AFCI receptacle as the first receptacle protecting down line receptacles unless you follow the NEC rules (see below and don't fall asleep reading it). Long story short in order to use an AFCI receptacle you must use MC from the panel to the first receptacle then house the receptacle in a metal box etc; yada yada yada. In the long run it is usually cheaper just to use the AFCI breaker. NOTE: It must be a CAFCI breaker. (C.ombination A.rch F.ault C.ircuit I.nterrupter). A mistake that many people make when reading this is thinking combination means AFCI and GFCI protection. Although there are such breakers what this rule refers to as "combination" is that the AFCI breaker protects both series and parallel arch faults. So yes, the extra breakers included with the purchase of the panel are basically useless except for just a few rooms in the house, like the basement and I think a utility room at this point.

I believe that CAFCI is a newer version of AFCI. Does it need to be CAFCI according to this new rule?

CAFCI breakers make populating a new breaker panel a very expensive proposition. Some jurisdiction that even though follow the NEC otherwise make an exception for this rule, but unfortunately the county/city where I live make no such exception. I noted that the nearby homecenter mostly showcase AFCI circuit breaker switches.

What I normally use as a rule of thumb which has not failed me yet is if I walk into a room and a light switch is within my arms (both arms stretched out in a line from doorway to doorway) reach then no 3 way switch is needed. Hope you got that.
I will try this rule. But, in doubt, I may simply install two switches.

210.12
AFCI receptacle instead of AFCI breaker can be used if:
(4) A listed outlet branch-circuit type arc-fault circuit interrupter
installed at the first outlet on the branch circuit
in combination with a listed branch-circuit over current
protective device where all of the following conditions
are met:
a. The branch-circuit wiring shall be continuous from the
branch-circuit over current device to the outlet branch circuit
arc-fault circuit interrupter.
b. The maximum length of the branch-circuit wiring from
the branch-circuit over current device to the first outlet
shall not exceed 15.2 m (50 ft) for a 14 AWG conductor
or 21.3 m (70 ft) for a 12 AWG conductor.
c. The first outlet box in the branch circuit shall be marked
to indicate that it is the first outlet of the circuit.
d. The combination of the branch-circuit over current
device and outlet branch-circuit AFCI shall be
identified as meeting the requirements for a system
combination–type AFCI and shall be listed as such.
(5) If RMC, IMC, EMT, Type MC, or steel-armored Type AC
cables meeting the requirements of 250.118, metal wireways,
metal auxiliary gutters, and metal outlet and junction
boxes are installed for the portion of the branch circuit
between the branch-circuit over current device and the first
outlet, it shall be permitted to install a listed outlet branch circuit
type AFCI at the first outlet to provide protection
for the remaining portion of the branch circuit.
(6) Where a listed metal or nonmetallic conduit or tubing or
Type MC cable is encased in not less than 50 mm (2 in.)
of concrete for the portion of the branch circuit between
the branch-circuit over current device and the first outlet,
it shall be permitted to install a listed outlet branch-circuit
type AFCI at the first outlet to provide protection for the
remaining portion of the branch circuit.

Yep, too many tidbits to follow. I will stick with the circuit breaker switches on the panel instead!
 
I believe that CAFCI is a newer version of AFCI. Does it need to be CAFCI according to this new rule?

CAFCI breakers make populating a new breaker panel a very expensive proposition. Some jurisdiction that even though follow the NEC otherwise make an exception for this rule, but unfortunately the county/city where I live make no such exception. I noted that the nearby homecenter mostly showcase AFCI circuit breaker switches.
Only your AHJ can answer your question about what is expected or accepted as a AFCI breaker

P.S. - friendly terminology correction- "circuit breaker" not "circuit breaker switch".

I will try this rule. But, in doubt, I may simply install two switches.
This is fine. It is your choice to use 3 way switching for more convenience and at your extra cost. I was just referring to when I wire a home without electrical plans given to me in advance. I will normally consult with the owner as to their personal preference and discuss with them their options. As long as it meets minimum code I do as they request. If they want to spend the extra money on the labor and materials then so be it.
 
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