splicing THWN/THHN in conduit

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Old 11-08-02, 09:50 AM
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splicing THWN/THHN in conduit

We have over 600 feet of underground conduit along our driveway (1 1/2"). We will be putting 2 lights at the end of the driveway so I was going to run stranded 12 gauge THWN/THHN wire. However, it only comes in 500 or 2500 foot lengths. What would be the proper way to splice it since it will be in conduit?
Thanks.
Dave
 
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Old 11-08-02, 10:10 AM
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splicing in a conduit is a huge no-no!!! it seems whoever ran the conduit did you wrong by not putting any boxes in the run. how will you be putting this wire in the pipe, surely you dont expect to feed it in manually by shoving stranded thhn? that pipe has got to have water in it. i suggest you use a vacuum or compressed air to send a "mouse" or foam plug thru it to clean it out and pull a string in it. also you should buy a 2500 ft roll of black wire, and stretch it out and mark the ends w/ tape for the neutral (white) and the ground(green). as my dad used to say the left over wire wont go bad in the garage. i also suggest using #10 wire to allow for voltage drop as you might want to add a gfi receptacle out at the lights for your convenience. (where are you gonna plug in the leaf blower?)hope this helps, any other questions post back
 
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Old 11-08-02, 11:11 AM
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Article 200.6 states that "Sizes 6 AWG or smaller. An insulated grounded conductor of 6AWG or smaller be identified by a continuous white or grey outer finish or by three continuous stripes on other than green insulation along its entire length.

I take this to mean that you would have to mark the wires for the entire length, not just the ends.

Tony
 
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Old 11-08-02, 01:13 PM
Wgoodrich
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If you are runnig 120 volts 600 feet on 12 awg copper wire using 3 amps about two 200 watt bulbs you would have approximately 6% voltage drop. If it were me I would increase that size wire to about three 10 awg copper wires or even better three 8 awg copper wires to compensate for any added load in the future. Do it now or hate yourself in the future.

Now as for junctions in this 600 foot runs, I would dig up that conduit and cut that conduit about every 200 feet. Then I would install a short treated 4 x 4 treated post about 2' tall above ground then I would install a device box and a weather proof drive way light on each of those post. This would be about three post down that driveway. This will give you about a 200 foot run between any pull box so you can surface that wire and make your splices as you need. I suspect you will need these pull boxes at least no more than 200 feet apart even with 12 awg wire. YOu will have a fit trying to pull 600 feet without a pull box.
This way you have a few more lights down the drive and the increased wire size on a 20 amp breaker will allow you to add a receptacle on a couple of places also if you like.

As for the white grounded leg and green grounding conductor 200.6 is right concerning grounded. If you install white THWN for your grounded leg and green THWN for your grounidng conductor then you have met that part of the NEC. I would install these pull boxes as suggested. Otherwise I doubt you will pull that wire that far without pulling the wires in two if that conduit has been there any time length at all.

Let us know how you come out

Good Luck

Wg
 
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Old 11-08-02, 02:03 PM
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not to get in a peeing match over code, the continuous white and green coloring is indeed in there, but i believe that is there so that no matter what box these wires go thru they will be identified as such. we're talking about a 600' run with no other boxes in it at all. digging up and adding posts is a great idea if that is possible meaning, is the pipe under the driveway? i'm told 1000' reels are available you might have to just shop around. if you can get the 1000'ers it sounds to me like the problem w/ my suggestion would be solved. pulling in the pipe shouldnt be a problem as long as you blow the line and use lube, lots of it!!!
good luck!!!
 
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Old 11-08-02, 03:41 PM
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You figure it that difficult to pull that wire in an 1 1/2 pipe? I pulled 3 no.2's in inch and a half, 100 ft with 4 turns,, no lube. if that pipe is straight 8 or 10 isnt going to be a problem.
 
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Old 11-09-02, 03:22 AM
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I'm with sberry27 on this one. Shouldn't be any problem at all, unless you've had gophers crawling into that pipe and dying. I'd say THAT would be a major impediment to your project.
 
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Old 11-09-02, 07:08 AM
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the pipe is 1 1/2" with no abrupt bends,etc except where it comes out of the ground. It has a thick yellow plastic (?poly) pull-rope in place and both ends have been capped since it was installed (about 2 years ago). I've been thinking of having our electrician pull the wires through (he had mentioned using a winch originally). Then I would do the wiring myself at a later date. I'm afraid of breaking the rope. What would be a reasonable price to charge for the labor a couple hundred bucks (besides the wire cost)?
Dave
 
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Old 11-09-02, 10:07 AM
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you and one other person could probably do the whole job in a day. from pulling the wire to tie in. not a big deal especially with the size of the pipe and wire. even tho its been capped off ill venture that theres some water in the pipe (thats just the nature of the beast) my suggestion to you is to get your wife, girlfriend, or significant other to help you with the pull, and spend the $$$ you were gonna pay the electrician on a nice quiet dinner for two. NICE!!!
 
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Old 11-09-02, 10:11 AM
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I have no idea what an electrician would charge to pull the wire through, but if that's truly heavy poly rope -- like 1/2" or more -- you're not likely to break it, so long as it's been out of the sun's ultraviolet rays, the only thing that will destroy poly rope.

Well drillers use it for safety rope on submersible pumps hundreds of feet in the ground.
 
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Old 11-09-02, 10:52 AM
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Thanks. maybe we'll give it a try. It is 1/2" poly rope I believe. I guess the idea would be to take all three conductors (white, black, and green) and bend them like a candy cane and tie the rope in the crook of the bend. then tape the be-jeesis out of the hook so nothing comes loose. Then i guess one person would push the conductors from one end while the other pulls from the other end. Sound about right? any other tips/tricks? We were thinking of having just two 60 watt lamps at the end of the driveway and maybe an outlet for occasional use. do you still think 8 gauge is the way to go. Then what would I do...change over to 12 or 14 gauge in the house and at the street in a junction box before i go to the lights and the switch in the house? So the last 10 feet or so would be 12 gauge?
Thanks again.
Dave
 
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Old 11-09-02, 12:16 PM
MTgets
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Dont forget to buy a bottle of wire pulling lube, and lube the taped up head really good, for Justin..........just in case.
 
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Old 11-09-02, 01:48 PM
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No. 10 AWG should be ample all the way, without unreasonable voltage drop.

I'd use a 20-amp breaker and 20-amp receptacles.

You could spend a few bucks more, use NM-B, 10/3 w/grnd and the white as a common return and do some interesting things with switches to control the light and outlets, if you thought there was a need for such.

Or, by using two single-pole breakers you could do that to create two separate circuits -- one for the light and another for the receptacles.

But if you can see no immediate or future need for such, there's probably no reason for doing it.
 
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Old 11-11-02, 10:17 PM
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Strip about a foot of the insulation off of the wire and then bend it around the eye of the rope. This will thin the head out and make it so you are not pulling twice the number of wires.
Brian
 
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Old 11-11-02, 11:42 PM
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This is an 1 1/2 pipe,, the size of the head isnt going to mean squat to this pull,,, any resistance is going to come from the drag of the rope and the wire laying in the bottom of the pipe. This pull is going to be easy,, thats a huge pipe for that wire. It would be no harder than dragging that along the ground 600 ft long,, maybe even easier. I drag a 400 ft 1/0 welding lead along the drive the other day. Not far,, but thats heavy compared to 3 number 10 wires which weighs what maybe 60 # total? That welding lead probably 250 # or so. There will be a bit of friction around the 2 bends but nothing to sweat especially with a helper feeding it with a little push thru the first one. What would it take,, maybe 10 mins for you and a helper to install that wire?
 
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Old 11-12-02, 06:13 AM
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Tie a new piece of rope onto the wire bundle so you have it in case you want to pull more wire at some future date.
 
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