I am an accomplished DIYer that is familiar with some electrical work.But when it comes to wiring the 60A Sub Panel in my barn, I am not going to do it myself. A little gun-shy of getting it right. But I do want to add 2 lights and a receptacle. So I plan on adding a 20A breaker in the main box and wiring up one circuit to the barn. So here’s my questions:
There is 1″ PVC conduit in the ground already. I will be pulling wires approx 120 feet through the conduit (from the house to the barn) Only one 90 in there but the conduit does meander slightly around an old silver maple. No sharp bends though other than the already mentioned 90 to come up out of the ground at the barn.
What’s the best way to pull the wire? a 200′ tape or I’ve heard (but never used) of a device that you suck through with a shop vac and then pull a pull rope into the conduit.
Secondly, the only THHN I can find in #10 is stranded. I assume because solid #10 would be darn near impossible to pull. I know that terminating the stranded is more difficult than the solid. Should I hunt for solid or just use the stranded? And is #10 the correct size for this length of run? I wouldn’t think the voltage drop over 100′ would require any heavier wire.
Thirdly, I plan on pulling #10 because I want to have an electrician install a 60A subpanel in the future. For this I need three conductors, one for each hot leg and one return. The subpanel will not be bonded to the house system- it will be grounded at the building when it is installed. So for argument, I need one black one white and one red.
But I want to just pull the #10 now and use it for a 20A circuit with the upgrade left for the future. Because of this I need a ground back to the main load center. I hate to pull a 4th wire if it isn’t really necessary, but I don’t think it’s acceptable to use the red wire i pull for the eventual hot leg as a ground for now. Can anyone comment? If need be, I’ll just buy 130′ of the green wire too and leave it unused when I upgrade later.
Thanks for any and all comments.
Replies
I avoid electrical work like the plague, but I'll bet that #10 is grossly undersized for what you plan. If all you did was two light and a receptacle for a radio, it might fly. But adding a 60A panel is a hole nutter ball game.
The device you mention for the shop vac ... tie a piece of foam rubber to a light string, suck it through, then pull in something heavier to pull the wires.
I'm sorry, I thought you wanted it done the right way.
a sammich bag works more better.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Yeah, but when I tried that, the ham and swiss got stuck in the pipe.
I'm sorry, I thought you wanted it done the right way.
same damn thing happened to me when a plumber told me to stuff a wet pipe w/bread before soldering...cheese dripped all over the joint, the ham started to burn...smelled like a deli for weeks.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
You are suppose to put mayo on it first.Lubes of up the conduit.
suppose to put mayo on it first
Is that tinning mayo or regular?Occupational hazard of my occupation not being around (sorry Bubba)
Thats the problem, I used pb&j. Stuck up the whole thing.
Yeah, but when I tried that, the ham and swiss got stuck in the pipe.
Mama Cass had the same problem.
oh man that is bad...dint karen carpenter try to give her mouth to mouth?
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Yeah, but she ate her.
Just to clarify, by #10, I mean 10 gauge. Rated for 30A. Thanks, guys, I'll try the sandwhich bag.
But that is not enough if you want max capacity on a 60 amp sub-panel.And at that distance you need to go up one wire size because of voltage drops.I would go ahead and pull #6 and include a ground wire.
I gather from his post that his electrician is going to install a 60 amp subpanel at some later date. Meanwhile he wants to run a 20 amp circuit for lighting and a receptical. The #10 stranded would be fine for that single circuit, and the electrician could use it to do a pull out/pull in later. He could terminate in a j-box and finish the runs to devices with #12 solid. Make landing the wires easier, than trying to with #10 stranded.
Dave
I thought the other, that he wanted wire that could later used to for the sub-panel. That is why the question of the ground comes up.Hey! I thought that you would be on the working end of a snow shovel.
Spent 18 hours out there yesterday. Took 1.5 hr. to get the 31 mi. home. Got in about 1:00am, and crashed.
I am back at work now. Just warming up after digging out 5 doors and an outside air damper on the roof, that were drifted in. Stuff was frozen so hard I had to get a flat nose steel shovel to chip it loose, then get on my knees and pitch it out by hand. Now I need to replace ceiling tiles and clean up the work spaces they bombed when they fell out of the ceiling. I should be done in an hour or so.
Parking lot and sidewalks look pretty good. The contractor that is part of our "plan B" hasn't stopped since 7:00am yesterday morning. Bet he buys some heated cabs for his eguipment after this.
The intestates are in good shape in the Louisville area, but north of us they are still FUBARed. Some places as close as 30 miles north got up to 3'.
I spent 6 hrs. this morning clearing part of our road and a couples driveway (about 1/3 mile of it mostly up a big hill). I know Boss hates them, but bless that little JD 970 tractor. Between it and a neighbors Kabota we got everyone out that needed to get out. Maybe we won't have to get out in it when the bottom falls out tomorrow night ... -7 degrees is what they are calling for.
At least since I am on call, I get to drive an F250 4x4. Makes DW feel a little better about me going out to play.
Dave
Good call Dave. I missed that option. If he follows what you say, it sounds like a plan. I thought he wanted to pull the permanent wires now.
I'm sorry, I thought you wanted it done the right way.
That's the ticket, want to pull the permanent wires now. After looking up the formulas and performing some basic calculations, looks like I'll be going #6 wire.
Thanks for your input guys.
there ain't no way to fit let allone pull 3 #10 wires through a 1" conduit even if it was already empty ..
Actually, according to my cheat sheet, 3 #10s will fit just fine in a 1" conduit...for that matter, 4 #6s will fit as well (two hots, a neutral and a ground) but it probably wouldn't be a bad idea to go to 1 1/4 or 1 1/2 just for insurance.By the way, there are a number of voltage drop calculators online that can be pretty handy. The one I use is at http://www.electrician.com/vd_calculator.html . You want to keep the voltage drop at 3% or less (3.6 volts on a 120 circuit, 7.2 volts on a 240 circuit.)Oops - I re-read the original post and the 1" conduit is already in the ground. In that case I'd go ahead and use it for the #6 wires. This is assuming you're going to use THHW/THWN stranded wire for the pull.
Edited 12/23/2004 2:02 pm ET by Stuart
He could probably PUSH the wires through . . . as long as he first inserted the sandwich with mayo for a running pre-lube.
It is not legal to reidentify a conductor as small as #10 with tape or paint, A #10 is the correct size bond for a 60amp circuit. If you use a rope use the largest diameter that fits with a loop and wire tied on...the smaller jetlines and pull strings will saw through the inside of the 90, something like 1/4 inch would work for 1 inch conduit, many of our jobs spec. steel 90's with pvc just for this reason. A 60 amp sub-panel requires #6 for the feeders and perhaps you could use #8 for a neutral if you balance your loads. Why not pull all the wire now, you can always fuse it at 20amps until you are ready to install the panel.
What you want are called "conduit pistons"; the collequial term is "mice". See http://www.toolup.com/productinfo.asp?id=610-5&Manuf=Greenlee . It pulls a lightweight strng through the conduit, which you use to pull a stout rope through.
I have a 200' run of 1" PVC conduit going to my TV antenna back in the yard (needed to be back there to avoid a hill). It has 2 90's and 2 45's. The mouse just flew through that length, using just a standard shop vac.
6 AWG is marginal for this application. You need to use 90 degree C rated insulation to get 60 ampacity when in a raceway (conduit). Plus, you'll get 3% voltage drop just in this feeder alone.
However, 3 #4 AWG conductors just barely fit in a 1" PVC conduit, so it may be a hard pull. The best bet may be to use 2 #4 for the hots, and one #6 for the "neutral" (called "grounded" in the NEC for single-phase) conductor. Use pulling lubricant.
Since you're not running a separate equipment grounding conductor to the barn (no room in the conduit), you still need to install a small panel that listed to use as a main, even for just one 20A circuit. I would just go ahead and install the 60A panel now. It is wired like a main panel in this application, with "neutral" and grounding bus bars bonded together, and connected to a grounding electrode system at the barn. So you need to install 2 ground rods at the barn. Any metallic piping at the barn must be bonded to the grounding electrode system.
This will work if you don't have any type of metallic pathway (e.g., water pipes) running from the house to the barn. If you do, you need to run 4 conductors, and configure the barn panel as a subpanel (i.e., "neutral" and grounding bus bars stay separate).