UPDATE: Using existing outside outlet to power another through conduit

[ScaldedDog]

I have an existing outlet on the outside of a 40+ year old home in FL. We added an enclosed patio, and ran conduit under the pavers to where we need another outlet. What's the right way to get the wiring in the wall out to the conduit, while still powering outlets in the existing location? It looks like this:



As I'm writing this, I'm thinking I may be trying to combine things that ought not be combined, in that I'm wanting a single box that both provides egress for the house wiring, mounts outlets, and allows connection to the conduit. Is the right way to do this to simply put an in-use cover on the existing box, then fish wire down from that box and out into a conduit body to provide separate egress and conduit connection? If that's the case, is simply screwing the conduit body to the house and using silicone on the back around the hole enough? It seems like I'd need strain relief on the inside of the wall, but I'm not sure how I'd do that.

Mark

 

[mike93lx]

Surface mount box on top of the existing with the conduit into the bottom

 

[ScaldedDog]

Surface mount box on top of the existing with the conduit into the bottom

I thought about that, but wasn't sure I could just drill a hole in the new box to egress the wire.

Mark

 

[wyliesdiesels]

I thought about that, but wasn't sure I could just drill a hole in the new box to egress the wire.

Mark

you wouldnt drill a hole in the box. the box would have a threaded hole for connecting to the conduit with a terminal adapter.

 

[mike93lx]

I thought about that, but wasn't sure I could just drill a hole in the new box to egress the wire.

Mark

Get a box that has openings on the back and bottom. They'll be readily available.

 

[dscheidt]

I thought about that, but wasn't sure I could just drill a hole in the new box to egress the wire.

Mark

you don't. You use a box or box extension with a conduit port on it, something like this: https://www.amazon.com/Hubbell-5400-5-Extension-Adapter-Gang/dp/B000FK9WWM?tag=atomicindus08-20
Your local store will have a suitable part. Don't forget that if your exisiting box is plastic, you need to attach a ground wire to the metal box (and you can't terminate metallic conduit in a plastic box, so if you conduit is metal, use metal box. )

 

[ScaldedDog]

Thanks for your help on this, guys. I forgot when I first posted that I want to add a ceiling fan, too. It seems straightforward, but I'm hoping you guys can help me with a couple of details, and any potential issues. Referencing the photo below:

1) The roof panel has a fan beam (essentially a rectangular aluminum tube sandwiched inside the roof panel, surrounded by insulation) the center of which is marked by the thin blue line running across the roof panel. The fan will mount where the yellow rectangle is.

2) My plan is to run THHN down into the conduit entrance on the left of the floor, and up from the conduit exit on the right, through a piece of flexible liquidtite (green line) into a 2-gang PVC box (green box). The box will hold an outlet (GFCI protected by the outlet on the house wall ((not shown)) and the fan switch. The wire from the switch to the fan will run up the patio riser into the roof panel's fan beam, then through it to the fan.

Questions:

1) Any issue with the height of the box on the right side of the patio? If I put it where I'd like it, the top of it would be 17" off the pavers.

2) How do I protect (and support?) the wire inside the patio riser, and at the 90* bend from inside the riser to inside the roof panel. Access will be difficult, so I don't expect the hole drilled into the aluminum roof panel to be particularly clean.

3) Any issue with using THHN inside the riser and roof panel? (I'm not opposed to using something else, but I'll have plenty of THHN left over.) I know the conduit beneath the pavers is considered a wet location, but is inside the riser and roof panel? Does it matter?

4) Both the roof panel and screen riser need to be grounded, correct?

School me. I may end up hiring this out, but still need to understand how it should be done.



Mark

 

[Reborn]

Stick with conduit all the way through. That will protect your wire. THHN should not be run without conduit, anyway, so you'd need to switch to NMB (romex) for the roof run. I would personally run the conduit all the way through and use THHN/THWN and then you don't need to worry about wet/dry.

 

[wyliesdiesels]

I wouldnt run any wire inside that support. Use conduit instead