I am running outlets for my bedroom now, seperate circuit from my lights. How many outlets can I run on 12/2 romex wire before I start to see power being drained from a vacuum, or a lamp,etc....? I was hopping I could get atleast 6-7 from this one circuit (20amp). How do I answer back to this thread so other members know I am responding to there answers. If they just see the replies getting higher in number or already answered my question they wount think about viewing the question again. Other message boards have the ability so members know if the original person with the question is replying back to them, those this one.

 

If the outlets are on a separate circuit, you can run 6,238,726,421 receptacles on the circuit before the lights dim. Six or seven if fine.

 

There is no set limit on the number of outlets. 10 outlets on a 20A breaker is not unusual. More outlets does not increase the load on a circuit, what you plug into those does. Thus, you need to plan what you need based on what you plan to plug into those outlets.

You stated that this is a separate circuit from the light. Why then do you think more outlets would cause your lights to dim?

BTW: Since you are doing new wiring in a bedroom, you must use a AFCI breaker to protect that circuit.

 

wow, ok thank you. I had no idea i could run that many. would that be the same for 14/2 romex wire. What is the differnce other than the gauge. Does the 12/2 pull more power from the panel causing higher electric bills?

 

Load calcualtion for a general purpose receptacle circuit is 180VA per receptacle. VA = 120 Volts X 1.5 Amps.

 

This is not true in all areas. In my area this requirement has not been adopted as of yet. Though I have no personal experience with these the inspector who did my recent inspection indicated that these breakers were the subject of local debates regarding false trips.

I would check locally for the requirements in your area. If they are not required then you can investigate and decide for yourself the value of these devices.
Scott

 

Sean,

I think all areas have adopted atleast the 1999 and in the 1999 is states that effective 1/1/2002 as listed in 210-12 of the 199 NEC so I am thinking if they adopt at the least that code it should be enforced as of 1/2/2002 in all areas.....I know they did it here in my area once Jan hit of 2002.

 

My area has not adopted AFCI's yet either. We are under 1999 but they do not enforce the AFCI rule. Until Jan. '06 when we are adopting 2005 I will not use them.

Also:This is not used for residential load calcs. Like has been said, there is no limit on number of receptacles, but 10 is a generally accepted number.

 

Local modifications to the AFCI rules in both the 1999 and 2002 are very common.

By code, #14 wire can be protected by a 15-amp breaker.
By code, #12 wire can be protected by either a 15-amp or a 20-amp breaker.

The difference between #12 and #14 will have no measurable difference on your electric bill.

Give the same amount of current and length of wire, #12 has less resistance and will cause less voltage drop than #14. Thus if you did have lighting and receptacles on the same circuit, the lighting would be less likely to dim if the wiring were #12.

One rule of thumb, and it's just a rule of thumb, not a rule of law, is to put no more than 8 receptacles on a 15-amp circuit with #14 wire, or 10 receptacles on a 20-amp circuit with #12 wire. For each lighting fixture you add to the same circuit, subtract one receptacle (very roughly speaking).

 

You're right if he's not going to use the new receptacles for general illumination. But PugGuy2001 said they would be separate from his lights.
So I take that to mean they are considered 'general use receptacles.'

Ref: NEC 2002 Articles 220.3(B) and 220.11

How would you calculate the load?

 

In dwellings receptacles are included in the general lighting load calculations.

220.3(B)(9)Receptacle Outlets. "Except as covered in 220.3(B)(10)..."
and especially: 220.3(B)(10) Dwelling Occupancies

 

As I understand it, article 220 plays no role at all in the design of an individual residential branch circuit. The purpose of article 220, for residential, is to compute the demand load of the residence. So although you might compute a branch circuit load in order to add its contribution to the dwelling load, it has no bearing on the design of that one circuit.