Question on light switch wiring

[green.bubbly]

I have seen it done both ways and was wondering if there is any advantage or disadvantage when wiring a light/switch circuit. When I ran the wiring for my garage, I ran a line from the breaker to the first light box. I then ran a line back to the switch, like in the pic below.

I have also seen the line from the panel go to the switch then to the light like this pic.

 

[mrb]

do it whichever way makes sense based on location of panel, lights, switches, etc.

if you are under nec 2008, depending on circumstances you may be required to have a neutral present in the box if you do it like the first picture

Switches controlling lineto-neutral lighting loads must have a neutral provided at the switch location [404.2(C)] unless either of the conditions of the following exception is met.

Exception: The neutral conductor isn’t required at the switch location if:

The conductors for switches enter the device box through a raceway that has sufficient cross-sectional area to accommodate a neutral conductor.

Cable assemblies for switches enter the box through a framing cavity that’s open at the top or bottom on the same floor level, or through a wall, floor, or ceiling that’s unfinished on one side, as shown in the Figure.
Note: The purpose of the neutral conductor is to complete a circuit path for electronic lighting control devices

 

[Charles (in GA)]

If you do it like the first one, be sure and do the wiring as it shows, with the black wire returning from the switch to the light fixture, and the white wire (remarked as black) carrying the hot to the switch. Do not reverse this situation as code does not allow you to remark the hot switch leg from the switch to the light fixture.

Charles

 

[green.bubbly]

do it whichever way makes sense based on location of panel, lights, switches, etc.

if you are under nec 2008, depending on circumstances you may be required to have a neutral present in the box if you do it like the first picture

Switches controlling lineto-neutral lighting loads must have a neutral provided at the switch location [404.2(C)] unless either of the conditions of the following exception is met.

Exception: The neutral conductor isn’t required at the switch location if:

The conductors for switches enter the device box through a raceway that has sufficient cross-sectional area to accommodate a neutral conductor.

Cable assemblies for switches enter the box through a framing cavity that’s open at the top or bottom on the same floor level, or through a wall, floor, or ceiling that’s unfinished on one side, as shown in the Figure.
Note: The purpose of the neutral conductor is to complete a circuit path for electronic lighting control devices

Thanks.

Stupid question about the nec 2008 code. Basically, it makes no sense to me, (surprise) especially the bolded part. Am I reading that correctly, if the raceway (conduit ??) has enough room for a neutral then it is not required?

So if it did not have enough room, it would be required? No comprehend. Seems backwards.

 

[Charles (in GA)]

Switches controlling lineto-neutral lighting loads must have a neutral provided at the switch location [404.2(C)] unless either of the conditions of the following exception is met.

Exception: The neutral conductor isn’t required at the switch location if:

The conductors for switches enter the device box through a raceway that has sufficient cross-sectional area to accommodate a neutral conductor.

Cable assemblies for switches enter the box through a framing cavity that’s open at the top or bottom on the same floor level, or through a wall, floor, or ceiling that’s unfinished on one side, as shown in the Figure.
Note: The purpose of the neutral conductor is to complete a circuit path for electronic lighting control devices

Where are you getting this from. My 2005 and 2008 codes do not have a 404.2(C), they only have (A) and (B) and do not have any kind of exception like this.

Charles

 

[mrb]

Thanks.

Stupid question about the nec 2008 code. Basically, it makes no sense to me, (surprise) especially the bolded part. Am I reading that correctly, if the raceway (conduit ??) has enough room for a neutral then it is not required?

So if it did not have enough room, it would be required? No comprehend. Seems backwards.

basically it means if theres no way to get a neutral in later you have to put it in when installed.

 

[green.bubbly]

basically it means if theres no way to get a neutral in later you have to put it in when installed.

Ok, now that makes sense. Thanks

 

[green.bubbly]

Here is a good explanation in the youtube link below. The neutral conductor could be required if the switch device such as a motion detector switch will be used in the future. So lets say you wanted to add a motion detector switch down the road. It would require a neutral and if there is no way to add a neutral in the future, then it must be ran during initial wiring.

 

[mrb]

the reason it became required to install the neutral was due to more switch devices requiring a neutral and people bootlegging the device neutral to the ground when no neutral was present.

 

[Gooch]

I prefer to do it the second way, don't care much for the first one.

 

[rabidsquirrel]

-edit-

Never mind, it is romex.

 

[VHF]

If you do it like the first one, be sure and do the wiring as it shows, with the black wire returning from the switch to the light fixture, and the white wire (remarked as black) carrying the hot to the switch. Do not reverse this situation as code does not allow you to remark the hot switch leg from the switch to the light fixture.

Charles

Do you have a code section for this? My personal preference would be to remark the white as red and use it as the switched hot... but sounds like that might not be allowed!

 

[Joe92GT]

I like the new code. Yes, it means running 3 wire, or possibly adding more cost, but it makes life so much easier in the future.

I can't even count how many times someone wanted to add a light to a switched outlet room set up that didn't have a neutral in the box. Or even a ceiling fan.

BTW, I HATE switched outlets. I still see brand new houses built with switched outlets, why can't they put a ceiling fan box in the middle of the ceiling. Just put a naked light bulb in to sell the house. 10 extra dollars for each bedroom makes life so much easier.

 

[mrb]

I still see brand new houses built with switched outlets, why can't they put a ceiling fan box in the middle of the ceiling. Just put a naked light bulb in to sell the house. 10 extra dollars for each bedroom makes life so much easier.

the tract home builders do that on purpose so they have the option of selling fan/ceiling light prewire as an upgrade. switched outlet meets code minimum.

 

[gatchel]

If you ever want to use any kind of home automation or powerline lighting control make sure there is a neutral in every box. It really doesn't make much sense to do it the "old" way...

Also, with a neutral at the switch box you can easily add another switch to control another device down the road (as said above)