Outdoor Light Project - Questions

[Reborn]

I'm basically looking to expand my lighting both in front and behind the house (2 separate, but very similar, projects). Each project is comprised of the standard set up that you find in most homes: a switch that turns a single light fixture on/off. Both circuits are 15amps with 14/2 NM-B. My plan is to run 1/2" PVC conduit to the existing boxes. For the back side of the house, I am going to extend the current box and install a surface mount box; from there, I will run conduit surface mount along the house. For the front side of the house, I am planning to run the conduit in drywall (through about 5 studs), then pop out the front of the garage where I will run the rest of the conduit length outside, surface mounted. Inside the PVC conduit will be 3 THWN solid wires: 14 ga in black, white, green. Anything wrong with this plan? And is there any consideration or additional step needed depending on whether the existing boxes are metallic or plastic? I am planning to ground all lights I add, and they will be LED so I don't think there's any real concern for the added loads (all existing lights on these circuits are also LED). I'm also going to swap the switches out with astronomical timers (I actually did the front today to play around with the timer).

These questions are out of pure curiosity - could I use bare wire (like in NM-B) for the ground wire? And is the only consideration to use stranded wiring for flexibility? I'm not making any crazy bends so I'm pretty set on solid wiring, but want to make sure I understand the pros and cons of each.

 

[Zeke]

No bare ground wire in conduit. Flex is flex so if you have solid and want to use that, use it. PVC exposed to sun does deteriorate but EMT does rust too. Painting both helps with protection and aesthetics.

You need raintight connections and outdoor boxes on exterior surfaces.

 

[Reborn]

Thanks. The front side will be run under the eaves so it will have minimal sun exposure. In fact, it's already there and painted - I'm just going to tie it into a different circuit and replace the wiring in the conduit to do it correctly. The backside will have sun/water exposure but I am planning to paint it as well to blend it with the house.

I don't have the wire, but I'll go with solid to match everything else in the house (plus it's a few bucks cheaper).

For water-tight connections, I'm using pvc cement for all pvc-pvc connections. What about threaded fittings that enter the electrical boxes; do I use teflon tape? PVC cement? Something else?

 

[Sumboodie]

No bare ground wire in conduit. Flex is flex so if you have solid and want to use that, use it. PVC exposed to sun does deteriorate but EMT does rust too. Painting both helps with protection and aesthetics.

You need raintight connections and outdoor boxes on exterior surfaces.

Bare ground is fine per NEC. Maybe your local rules don't allow it?

 

[alfredeneuman]

Bare ground is fine per NEC. Maybe your local rules don't allow it?

Bare copper grounds should not be used with aluminum conduit and flex because of the dissimilar metals. Otherwise, it's OK according to the NEC.

 

[Sumboodie]

Bare copper grounds should not be used with aluminum conduit and flex because of the dissimilar metals. Otherwise, it's OK according to the NEC.

Makes sense. Ive never seen aluminum, but I'm usually just sourcing common stuff.

 

[dave*99]

Include expansion joints in the PVC as needed.