Installing light & switch into existing circuit - junction box requirements

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Old 06-22-14, 09:24 PM
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Installing light & switch into existing circuit - junction box requirements

Hey All,

I'm about to insulate my attic (spray foam and loose fill). But before i do i thought i might install a light + switch in one of my closets which doesn't have one and is too dark to use.

Now recently i had my wiring re-done and knob and tube removed. The dragged wiring up from the basement between the walls to the attic and then down to the 2nd floor rooms. I'm hoping to use some of this wiring. However i believe all the junction boxes for the wiring are down in the basement.

So my question is, if i want to cut into one of the wires which brings up power to one of my existing light circuits, and install a new junction box. What would be the requirements? I'm assuming that the attic will become quite inaccessible, especially the floor which will be spray foamed. Any any junction box in there won't be accessible.

Is a better option to create a junction box from an existing electrical box that houses the wiring for one of my second floor room light switches and then route wires from this to the location that i want my closet light?

cheers
oman
 
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Old 06-22-14, 10:15 PM
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However i believe all the junction boxes for the wiring are down in the basement.
Not likely. If they brought new feeders up from the basement into the attic for the second floor then I would expect to see junction boxes in the attic. They may have even run new circuits from the panel all the way to the second floor locations with no junction boxes anywhere. If there are any in the attic.... they can't be buried.

You would need to determine if the live feed you need is at the light fixture or the switch box. That would be the place to get power from.
 
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Old 06-23-14, 07:43 AM
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You will also need to consider the clearance requirements from the storage area and the fixture type. Is this a walk-in closet or just a shelf behind a door?
 
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Old 06-26-14, 09:48 PM
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Thanks PJmax and PCboss,

I'll be removing the old insulation soon so perhaps i'll find a junction box. It's definitely not obviously in the attic. It did appear they pulled up 4 cables but i'm not sure where they all went.

I was assuming if i wanted a live feed i would be opening up a light switch and taking it from before the switch, routing the cable up through the attic then down into the wall where i want the switch (then up again to the light fixture).

The closet is a small walk in with shelving, probably 1.5x5' withe 3' of shelving (not much room). What clearance requirements are we talking about? clearance of light from door swinging? clearance of light (hot) from walls and ceiling? Above the door opening is the hatch to the attic, but there should be a little room beside the opening before the shelving.

cheers
oman
 
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Old 06-26-14, 10:19 PM
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I was assuming if i wanted a live feed i would be opening up a light switch and taking it from before the switch, routing the cable up through the attic then down into the wall where i want the switch (then up again to the light fixture).
That is correct but you need to make sure there is an actual feed (always live) in the box as they could have just run a switch leg and then there would be no neutral there.
 
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Old 06-27-14, 06:08 AM
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An incandescent requires at least 12" clearance, a fluorescent at least 6".

https://www.google.com/search?q=nec+...tm%3B441%3B444
 
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Old 06-30-14, 11:19 AM
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Thanks again Pj and PC,

That's a great link PC (the 101tutoringlove.com).

PJ, thanks for the tip on the neutral. I'm pretty sure i've seen the neutral in one of the switch boxes i've already opened. I might post a photo when i get a chance.

cheers
oman
 
 

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