18 posts / 0 new
Last post
britjor
how many outlets and lights

I am finishing our basement, I have two separated sides separated by the stairs. The first side is 15 x 17, the second is 16 x 18. The first side is play room/computer room. The second is TV room. The first side I was going to put 4 outlets and 6 can lights with 14/2 wire. Is that okay? The second room will have 5 outlets and 6 can lights with 14/2 wire. Is that okay? I have a third circuit that will have two more outlets per room attached to a storage room. How far can I safely run 14/2 wire before the drop. Also what size wire for a ceiling fan w/heater on it?

Thank you for all the info

Fencepost
Re: how many outlets and lights

When laying out your outlets, keep in mind that National Electrical Code requires that no point along a usable wall be more than 6 feet from an outlet, and that cords aren't permitted to cross a doorway. Hallways are handled a little differently; I think it's no point on the floor can be more than 6 feet away (since hallways typically have only vacuum cleaners and night lights plugged in). The idea behind this rule is to avoid extension cords.

JimShortz99
Re: how many outlets and lights

Thanks for the tip...I will also keep that in mind as I finish my basement.

JLMCDANIEL
Re: how many outlets and lights

Voltage drop calculations are dependent on wire size, voltage, and load. As a general rule of thumb if you run over 100 feet you would go to the next size wire however for incandescent lights the only effect of the voltage drop would be slightly dimmer lights. There is no real code restrictions on length of run or allowable voltage drop.
I would suggest however that you run 12 ga (20 amp circuit) rather than 14ga for the outlets and have that separate from the lighting circuits. That way if you pop a breaker you won't be completely in the dark.
Jack

NEC
Re: how many outlets and lights

For some reason I have never figured out why, the National Electrical Code does not limit the number of plug receptacles on a residential circuit but they do in commercial to 180va (watts) and I like to use those values for residential calculations as well. The NEC also limits continuous loads to 80% of the value of the over current protection for the circuit. A continuous load according to the NEC is any load that last 3 hours or longer so will definitely include your light fixtures and I figure all loads on these types of circuits figure into that type of continuous load calculation.

So if we use those values you would be able to load a 15amp circuit to 12amps and a 20 amp circuit to 16amps of continuous duty at 80%.

So if we use some very simple math then volts x amps = allowable watts on a circuit.

12amps x 120volts = 1400watts (15amp circuit.) 16amps x 120volts = 1920 (20amp circuit.)

Take your light fixtures at face value when doing your calculations.

This, along with the great posts above should allow you to answer your question.

If Not…. Post back!

canuk
Re: how many outlets and lights
Quote:

For some reason I have never figured out why, the National Electrical Code does not limit the number of plug receptacles on a residential circuit

In Canada there is a limit as to the number of devices allowed on a general circuit.
For example ... a 15 amp circuit for lights and receptacles can only have a maximum of 12 ... whether they are all lights or receptacles or a combination of both. In some cases local regulations limit this number to 10 devices.

I agree about seperating the lights from the receptacles... this also limits the dimming or flickering lights .

Fencepost
Re: how many outlets and lights

It will be far cheaper to add circuits now while the walls are unfinished than to do it later.

Ernie_Fergler
Re: how many outlets and lights
NEC wrote:

For some reason I have never figured out why, the National Electrical Code does not limit the number of plug receptacles on a residential circuit but they do in commercial to 180va (watts) and I like to use those values for residential calculations as well. The NEC also limits continuous loads to 80% of the value of the over current protection for the circuit. A continuous load according to the NEC is any load that last 3 hours or longer so will definitely include your light fixtures and I figure all loads on these types of circuits figure into that type of continuous load calculation.

So if we use those values you would be able to load a 15amp circuit to 12amps and a 20 amp circuit to 16amps of continuous duty at 80%.

So if we use some very simple math then volts x amps = allowable watts on a circuit.

12amps x 120volts = 1400watts (15amp circuit.) 16amps x 120volts = 1920 (20amp circuit.)

Take your light fixtures at face value when doing your calculations.

This, along with the great posts above should allow you to answer your question.

If Not…. Post back!

I was always taught the the reason of no limit on outlets is because it lessens the chance of homeowners using those cheap brown extension cords. Might just be true.:cool:

NEC
Re: how many outlets and lights
Ernie_Fergler wrote:

I was always taught the the reason of no limit on outlets is because it lessens the chance of homeowners using those cheap brown extension cords. Might just be true.:cool:

Could be, I guess. It would mean though that you could put every single receptacle in a home in a home on a single circuit, not limited by other NEC resrictions and meet the requirements of the NEC.

JLMCDANIEL
Re: how many outlets and lights
NEC wrote:

Could be, I guess. It would mean though that you could put every single receptacle in a home in a home on a single circuit, not limited by other NEC resrictions and meet the requirements of the NEC.

But wouldn't that add to the fun of trouble shooting when they aren't working?:D
Jack

Timothy Miller
Re: how many outlets and lights

Howdy consider having an electrician come and bid the job. Did you pull a permit? I ask as its getting harder to ever sell a home without permitted improvements. Consider getting a books on basic wiring. Good workmanship and code mandates proper spacing and sizing of the lighting,outlets, wire, fasteners, boxes, GFRI recepticles ... a whole host of items to ensure safe construction.

Pages

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.