Wiring Run

[awitowsk]

I am planning on purchasing a 220v spa soon and will be running the wiring myself. The spa will be directly behind the house, the main panel is in the garage at the front of the house, about 60' away. I am planning 4 strand 6awg from a 50 amp double breaker in the main panel to a 50 or 60 amp gfci spa breaker box (haven't bought one yet) on the back wall of the house.

Rather than running conduit out of the garage, then burying it down the side of the house and around the back, can I run the wire through the attic? Its a single story house. I was thinking run conduit through the garage ceiling into the attic, then running just wire to the back of the house and back into conduit where it will be coming out the back wall. Are there any problems with this?

Thanks, Alex

[Raegor]

If you are using loose building wire then yes it must be in a conduit in the attic. If you are using romex you're good to go.

Building wire's insulation is too thin and hazerdous so code requires it to be sheathed in something.

I went through this with my electirican, he did what you're talking about, conduit outside but had the 4 building wire runs loose in the attic. When I asked around to other local electricians they said it had to be in conduit or romex wire. He came and switched it out to romex for free after I had to threaten to call the local code enforcement agency.

Of course your state could be different but I doubt it.

[hot_water]

Raegor is correct.

Your biggest cost will be the wire. If you use individual THHN or THWN you will need three lengths of #6 (red, black and white) plus a ground (green). Check your code, but usually you can use one size smaller (#8) for the ground which will save a few bucks. Even so, the price for all this wire will be an unpleasant surprise.

On the other hand, since it sounds like your load center is in doors (garage) you can come out using 6-3 w/ground NM (romex), go straight up into the attic, and put a junction box at the end of the attic run where you transition to conduit for the outdoor run to the GFI breaker, then conduit out of the GFI box to the spa. Home Depot has 6-3 w/ground NM for $2.36 a foot, which is still a bunch but will save you a LOT over the cost of individual THHN conductors. Plus of course you don't need the conduit and fittings in the attic.

Home Depot & Lowes both have the best deal I've found on the 60A GFI box - about $95. I got mine at Lowe's. It's a Midwest brand with a Siemens GFI breaker. Not sure what breaker is in the Home Depot version.

Even though it's cheaper, don't be tempted to run the NM (romex) in the conduit!! NM is NOT rated for use in conduit and may overheat. Not only will this fail inspection... it's not safe. In general it's never a good idea to skirt the NEC. In the conduit, you're stuck with THHN or THWN individual wires - red, black, white and green.

Most people run a short length of liquidtite flex conduit & fittings for the final connection to the spa. This makes life easy. But, per code, this last run of liquidtite has to be no longer than 6 feet. You can find the liquidtite already made up in 3 and 6 foot lengths, with fittings. This usually saves a couple bucks and is easier.

Finally, my advice is, use a bigger conduit than you need, generous lube, and keep the bends to a minimum. Three #6 & one #8 is not all that easy to pull.

Good luck.

-hot_water

[awitowsk]

Thanks guys, that was great information. I had not realized the 6-3 w/ground NM was an option for the indoors. Glad I am taking it one step at time.

I am still debating if I want to run through the attic or just dig and lay the conduit the whole way. I don't think I will have enough physical workroom to run the wire to the side of the house by the spa, so I would still have to come out about 30' away, only saving about 30' of digging.

I saw this bulk #6 single strand on bay for cheap, I am not sure what its classified as though. Would it be safe to splice a few feet of color coded THHN or THWN to each strand and use it for the bulk of the run inside conduit to save some money? Anyone know what this wire is?

Ebay wire link

[Dr. Spa]

You may wind up doing LOTS of splicing!

Per the ebay description, "PLEASE NOTE THAT EACH SPOOL YOU RECEIVE MAY BE MULTIPLE LENGTHS EQUALING 200 FT."

[hot_water]

Thanks guys, that was great information. I had not realized the 6-3 w/ground NM was an option for the indoors. Glad I am taking it one step at time.

I am still debating if I want to run through the attic or just dig and lay the conduit the whole way. I don't think I will have enough physical workroom to run the wire to the side of the house by the spa, so I would still have to come out about 30' away, only saving about 30' of digging.

I saw this bulk #6 single strand on bay for cheap, I am not sure what its classified as though. Would it be safe to splice a few feet of color coded THHN or THWN to each strand and use it for the bulk of the run inside conduit to save some money? Anyone know what this wire is?

Ebay wire link

I looked at the ebay listing and didn't see anything, either. You can click the "ask seller a question" button and try to find out what the spec is. If you don't get an answer I wouldn't buy it. The other concern I have is that while it's 200', it says in the listing that it could be (which means it IS) multiple shorter pieces totalling 200 feet. So you might have to do some splicing, and all splices have to be in an accessible box. A pain.

If the wire spec is something acceptable, you don't have to splice just to get the right color coding. You can re-code the wire using colored electrical tape. Home Depot or Lowe's has the colored tape.

As for the trenching, I guess you have to make that call depending on how soft your soil is and how much you like sweating. One thing to keep in mind is that different conduits require (per code) different trench depths. Where I live, PVC conduit has to be a minimum of 18" below grade, measured to the top of the conduit. That's a 20" deep trench or thereabouts. On the other hand, if you use metal (ridgid), it's just 6" to the top of the conduit - a lot easier on the back! You should check your local regulations on this issue of depth since the rules do vary. Also, the ridgid costs quite a bit more than the PVC.... you get to decide how much it's worth to dig less. Another idea is to not bury the conduit at all. I didn't do this, but here at least it's ok to run PVC above ground, secured along a fence or building wall for instance. Depending on your yard it might be horribly ugly... or not even noticeable. Finally..... they do make direct burial wire in the size you need. Personally, direct burial wire other than for LV landscape lights gives me the heebie-jeebies. But still, it's an option. Has to be in a pretty deep trench, though, as I recall

I should also mention that while it's good to plan so that you save as much money as possible... it is an electrical project and you can die. As such you should never violate code and more importantly you should never do anything that isn't totally bulletproof. There's no rule against making things better than code! I am not an electrician and only work on my own home.... I always go beyond the code, use the best available materials, minimize splices, use antioxidant on every connection and wire nut, tape every wire nut...you get the idea. It's critical that you take out a permit and get the work inspected.... it's water, electricity and your family's safety... wrong place to skimp!!

[awitowsk]

Thanks for the quick replies, the internet is amazes me sometimes!

I should also mention that while it's good to plan so that you save as much money as possible... it is an electrical project and you can die. As such you should never violate code and more importantly you should never do anything that isn't totally bulletproof. There's no rule against making things better than code! I am not an electrician and only work on my own home.... I always go beyond the code, use the best available materials, minimize splices, use antioxidant on every connection and wire nut, tape every wire nut...you get the idea. It's critical that you take out a permit and get the work inspected.... it's water, electricity and your family's safety... wrong place to skimp!!

I hear you. A hundred bucks or two is a tiny amount in this circumstance. Safety is #1, and I know the house will be unsellable if it is not done correctly. I enjoy learning all the options and finding the best balance. So far I like the attic/romex idea best. I am also going check the regulations in my area for the conduit along the building. The hot tub is going on the right side of the house on a deck, (it was built last year to support the load) the other side and back of the house walls are covered by shrubs and decking. I may be able to blend the conduit along the border between the siding and slab.