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Small Cabin Forum / Cabin Construction / Burying electrical cable
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Steeny
Member
# Posted: 4 Nov 2015 03:23
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I'm almost done building my 10x12 office shed in my yard. It is about 100' from my main house. I've temporarily been using an extension cord plugged into an outlet on my house, but I want to have electricity in the shed so I can plug in a small electric heater and use my laptop out there. My husband got a friend of his to come over and get things started on the electrical, as he has experience in that field. He said he'd let us know how much it is going to cost for the cord that can be buried. Well, all week I've been breaking my back swinging a pickaxe and digging with a shovel (as if having had seven kids wasn't already a back-breaking experience!), to make about a 12" deep channel, the whole 100' distance between shed and house, ready to bury a line, and tonight come to find out that the guy says we're looking at about $1000 for the cable in the appropriate type of sheathing that can be buried.

Seriously??? A thousand Canadian dollars? I was thinking maybe a hundred!

I checked with an old school friend who is now an electrician, down in the big city six hours away, and he said that is way too high a price. His recommendation was this:

"You need direct burial cable, you can use teck wire, or something cheaper called nmwu, can buy it at Home Depot. I'd recommend #10 size minimum, that's good for 30 amps, which would allow you to run lights, plugs, maybe even a heater."

I thanked him for his advice and said I'd look into it. And here is part of that looking-into. It's Greek to me. Does it make sense to anyone here? The part about "maybe a heater" is concerning to me, as I definitely need a heater here in a land that has snow at least six months of the year and can get down to -40 Celsius.

I sent my query to another old friend who has an electrical contracting business and I await his response, but thought I'd check in here, too. I am sure hoping it's not going to be anywhere near $1000, or even $500. Seems unreal. The extension cord I've got out there now has dealt just fine with my little electric fireplace and my laptop when I tested it out for a few hours, though I don't know if that means it's good enough for long term use.

Pookie129
Member
# Posted: 4 Nov 2015 06:38
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For a thousand dollars you could get a very decent reliable portable generator...that will more than pay for itself in the versatility in having a generator at your disposal. Not only for the shed, but if your home loses power, camping trips, hunt camps, tailgating, whatever....

Steve_S
Member
# Posted: 4 Nov 2015 06:55
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I would think that #10 AWG would service anything you need in that little shed.

The "heater" issue is that a lot of them can go from 500 watts up to 3000 watts. I think the average portable ceramic electric heater 750-1700 watts and use close to 15 amps which is typically one circuit. That would leave little room for anything else to be plugged in.

There is a good book available that digests the Electrical Code into easy to understand "English" which is available any most electrical supply departments. ELECTRICAL CODE SIMPLIFIED Canadian Edition, Multi-Province.

creeky
Member
# Posted: 4 Nov 2015 09:19
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By Canadian code you should be 24". I have that bright yellow book.

36" deep if you plan to drive over it.

Start swinging. You could put boards above to protect the wire. but ...

Call some of the local electrical places and see if anyone has end of roll nmwu. If you can find 10/3 that would give you 2 circuits. So you'd have one for the heater and one for lights and laptop.

Should cost, for a 50m (150') around 150 bucks. HomeD and Rona both carry it. Retail is often a bit pricier.

Did the 1,000 include installation to the panel and set up in the shed?

toyota_mdt_tech
Member
# Posted: 4 Nov 2015 10:28
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I'd get some direct bury stuff its gray here in the US and noted as UF for underground feeder. Bury it. I use a conduit over it just to keep it safe if I am ever digging around it. I suspect the first bid may be ditch digging, with subpanel all to code etc. And it might be close actually. The 10AWG is a good idea. I'd run 10-3 w/ground (4 wires if it was me) and you have the option of a single heavy circuit or adding the subpanel, running 220V and then splitting it.

pash
Member
# Posted: 4 Nov 2015 10:50 - Edited by: pash
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I actually did this exact thing a few months ago in Tennessee for a buddy. I put 100ft of #10 gauge direct burial, in some conduit that he already had so we figured might as well since he had it. took us 2 hours to hook up to the breaker box and install it to the box installed in the shed and bury the 100 ft. Think the 30 amp breaker was 8 bucks, and the wire was like $100. Now your trench isn't deep enough, and neither was mine thats why we ran it in conduit. you could also just get some pvc pipe and run it through that, anything to protect it. We had a box in the shed already and fed 2 15 amp circuits. However, im with creeky if the price was for the whole install and trenching, then he isn't cutting you a deal, but it is a reasonable price. As the boxes and wire in the shed will add another hundred or so and so will renting a trencher. And here in Tennessee electricians are 80-100 and hour. there you have it. He had an electrician come bid it and the price was like $600 for the one we did without any stuff in the shed.

bldginsp
Member
# Posted: 4 Nov 2015 12:48 - Edited by: bldginsp
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You should look closely at how much power you want to have in the shed. If you plan to keep it heated with electricity when it is very cold, 30 amps may not be enough for whatever heater you have and to supply other things. It may be, but with every electrical project, start with your power needs and work from there. The additional cost for using the next size wire up from #10 to #8 is not much and you want to do it right the first time. Have you heated the building in very cold weather using the extension cord you have now? Did it work? Were you running lights and laptop too?

Not sure what the burial rules are in the Canadian elec code, but you may not need to dig as deep a trench if you put PVC electrical conduit in the trench and run wire in that. Conduit is cheap and easy to install, and protects the wire better. Also, the wire you put in the conduit is cheaper than the direct burial variety. There's no good reason not to use conduit, in my opinion. It's only a little more expensive.

The majority of cost with any professional is labor, that's probably why you got such a high bid, and most of that was probably for digging. I'd get another bid, which excludes the digging part.

But I think I'd re-think trying to heat the building with electricity at all if you plan to use it in the very cold winter. If you went out there at 9AM to do some work, and turned on the heater, it would take an hour or two to heat up the building. Electricity is slow heat, and you don't want to leave it on 24/7 cause that will cost way too much. I'd suggest considering a small propane wall heater for heat, and 2-20 amp circuits for lights and laptop. The propane heater will warm you up in a few minutes and keep you toasty for the short period of time you spend in there during the cold, and in the spring and fall it will easily take the edge off with minimum use of propane.

Steeny
Member
# Posted: 4 Nov 2015 12:58
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The quote was from my husband's friend who is not an actual electrician but has experience in it. It was the price he said just for the electrical cable that is able to be buried.

My heater is 1500 watt. No idea on amps. Brand new electric fireplace that claims to heat up to 400 sf. My shed is less than 120 sf. I will be putting insulation in soon - Roxul R28.

bldginsp
Member
# Posted: 4 Nov 2015 13:01
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Any elec heater will take time to heat it up. What I envision is you wanting to be in there for an hour or two, which isn't enough time for the heater to heat it up, unless you leave it on 24/7.

$1000 for the wire alone is ridiculous. Check out Wire and Cable to Go.com for good prices on wire by internet order.

Steve_S
Member
# Posted: 4 Nov 2015 19:14
Reply 


#6 NMWU (underground wire) is $14.00 per metre @ Homedepot, #8 & #10 are cheaper. They are not listed on the homedeopt.ca pages, only full spools of 75m / 150m are listed.

100' = just under 31m. 31m x $14= $434 and that's for #6 which is good up to 60 amps

for example: 150m Spool of #8/3 NMWU is 1300.00
150m spool of 10/3 NMWU is 771.00

I just got back from buying my AC Breaker Panels and other bits and checked out the wire costs as I am going to have to pull #6 through my 4" O-Pipe from Power House to cabin.... Ohhh, so not looking forward to that.

Hope that helps
Steve

toyota_mdt_tech
Member
# Posted: 4 Nov 2015 19:56 - Edited by: toyota_mdt_tech
Reply 


Steve, is that wire aluminum? I know many times, heavy feeder, AL is used vs CU. Copper would also be much more $$$, maybe that was the heavy price????.

For the OP, if you do use aluminum wire (heavy Gauge stuff) make sure you coat the wire ends with the special additive to prevent corrosion where the AL wire meets the CU panel. One company that makes it is "Ideal" and its called Noalox

Amazon has it also.
noalox.jpg
noalox.jpg


Steve_S
Member
# Posted: 4 Nov 2015 20:03
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@Toyota, that is Copper... I haven't seen Aluminium wire used here in ages, not even sure it's available for purchase anymore. There was a lot of issues with Aluminium wiring years ago (late 70's / early 80's).

toyota_mdt_tech
Member
# Posted: 4 Nov 2015 21:13
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We dont use it for homes either, havent since the 70's, but they have/do use it to feed panels. But its always the real big stuff. I wasnt sure what they were burying by the ID ie NM## etc.
We have it here:

http://www.homedepot.com/p/Southwire-1-0-1-0-1-0-2-Aluminum-SER-Wire-By-the-Foot-1310 4599/205001906


Southwire's AlumaFlex SER is used for powering the service drop to the meter base and the meter base to the distribution panel board. It is also used for dryers, A/C units, ranges and heat pumps. It is available with 2,3 or 4 conductors.

600 Volts
For wet or dry locations
90 degree Celsius heat capacity
Aluminum conductors are compact stranded and assembled with reinforcement tape
Jacket is gray and made with a sunlight resistant polyvinyl chloride PVC
UL listed and CSA certified

bldginsp
Member
# Posted: 4 Nov 2015 21:16 - Edited by: bldginsp
Reply 


Aluminum is readily available in larger sizes for feeder cables. I think the smallest you'll see it is #6. Again check Wire And Cable To Go.com for prices, and they custom cut so you don't have to buy a whole spool. #6 three wire underground feeder is $.65 per foot, #4 four wire is $1.05 per foot. Copper is a lot more. To avoid problems with connections with aluminum, use Noalox as Toyota said, but also land it only in panel boxes on lugs made for the purpose, never splice directly onto copper.

Don_P
Member
# Posted: 5 Nov 2015 07:27
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We run aluminum for feeders. From having recently done this for 500' in Al 4/0 I'd run 4 wire from the main panel to a subpanel, separate grounds and neutrals and don't bond the neutral to the box or ground out there, send it all back to the main box with neutrals and grounds separate. You can run another ground rod bonded to the ground of the subpanel. Oh, that 4/0 cable had 3@ 4/0 wires and a 2/0 ground wire. Our antioxidant comes in a small red and white tube of paste. Got lucky, I picked up the wrapped spool at an auction.

creeky
Member
# Posted: 6 Nov 2015 09:44
Reply 


you won't see aluminum in Canada. just as you won't see 10/3 without a ground.

I got over 200 feet of #10 and #12 nmwu from an electrical supply store along with a few hundred feet of assorted 14/16g for less than 200 bucks. All of it end of roll they were clearing out.

It is fall clearout time. Is it worth making a few phone calls?

toyota_mdt_tech
Member
# Posted: 6 Nov 2015 10:24
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Quoting: creeky
you won't see aluminum in Canada. just as you won't see 10/3 without a ground.



Creek, we don't use AL for anything except feeder. No AL feeder in Canada?

Why no 10-3 with ground? Interesting really?

ColdFlame
Member
# Posted: 6 Nov 2015 10:46 - Edited by: ColdFlame
Reply 


Aluminum wire is available in Canada, though it's typically only found through wholesaler's or electrical supply houses (www.westburne.ca for example). Our local Home Depot's, Lowes, etc... only carry feeder wire in copper only.

At our place, the electrical feeds from our house panel to our barn/shop via pretty heavy gauge (don't know what gauge) aluminum wire on overhead power poles. It's a long run, and they ran two strands of it all the way down using the tension wire as the neutral. That said, our place was built in 1960...

Steve_S
Member
# Posted: 6 Nov 2015 18:35
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@ Toyota* I can only say that in Ontario Canada the only AL wire you can get is for Main Service lines and the code is quite specific that it has to be done by a Pro... Certified Inspection at minimum. Several years ago there was a lot of mess ups resulting in a lot of damage so they clamped down on it and virtually eliminated AL from the "consumer universe". Even the feed lines are encouraged to be Copper as opposed to AL.

@Steeny: Just wanted to let you know, that I purchased my 8/3 NMWU (copper of course) from Home Depot for my run from Powerhouse to Cabin... Cost was 9.95 per metre. I did so after checking with an electrical engineer friend and per code, #8 can support up to 45 Amps which is a fair bit of juice, especially for your application. You wouldn't need 8/3 (2 hot lines) you only need a 8/2 (one hot, one neg)
. Run that to a small sub-panel with 2-15A Breakers and do the lights with one circuit and plugs with the other (still overkill but room to expand) A 30A Breaker in your main house would feed that 8/2 and so you do not even need a Main Breaker in the Office-Shed.

Just some FYI:
1-15A Circuit can support 12 devices.
A device is a plug, switch or single light fixture. The general recommendation is to not exceed 10 devices per 15A circuit.

Code says use 1 plug for every 6 feet of wall, excepting where there is a door + swing space, or if a full height Window (to floor level or below 12" from floor).

Wet areas of course require CGFI.

I would very strongly suggest you avoid using an electric heater. There are many small heating systems, even small Rocket Stoves which you could essential burn twigs in and get a heap of heat from. There are commercial (retail) ones out there but you and hubby could easily make your own too. Next up a small Propane Heater with a 20lb tank outside... !!! CO2 Detector & Smoke Detector are a MUST !!!

I hope this helps and let's you get on your way to getting your "shed" up & powered, ready to be enjoyed.

Malamute
Member
# Posted: 8 Nov 2015 14:16 - Edited by: Malamute
Reply 


Im also in the "theres no good reason NOT to run underground wire in conduit" camp. As was said, you then dont need UF wire, though the plastic conduit doesnt cost that much in the size appropriate for your use.

Its been a while since I bought plastic conduit, but at about $3-$4/10ft stick, it isnt going to add much cost, and does add a lot of security. Ive heard of several people that started having oddly high electric bills. They cheaped out on burying wire and it ended up getting a nick or cut from a rock or underground varmint and leaked power. It cost far more to throw the electricity away than they saved by not using conduit. False economy at its finest.

For my part, Id never even consider putting wire in the ground without conduit. Its pretty rocky here, but the protection it affords if somebody accidentally strikes it with a shovel later will end up saving a lot of grief and work.

The cost you were quoted for the wire is insanely high.

Steve_S
Member
# Posted: 8 Nov 2015 19:23
Reply 


Hey Malamute ! Bet the dogs are getting happier that it's getting cooler now... Gosh I miss my Husky (but not the fur trail).

Ontario Code Book says to run a Yellow Tape Marker a couple of inches above the wire / conduit or plank (if used) so if you start digging and hit the tape you know your at the wire. It's also recommended to put the Wire / Conduit on a bed of sand and top it with sand to repent rock damage...

IMO some of it is a bit much but I can certainly see the benefit of it.

My underground Electric from Powerhouse to Cabin is 6' deep inside a 4" O-Pipe, the other 4" O-Pipe next to it is my water line... Both are housed in an XPS Foam Box (channel I made). Overkill ? YUP but better safe than sorry !

Power from my Solar Panels to Powerhouse will be in simple Flex Conduit with a protector plank above & 3' deep as that crosses my driveway. Sand I got so it will be there too. Again the whole better safe than sorry for something silly that should be done when doing the install.

Have a Terrific Day one and all !

Pookie129
Member
# Posted: 9 Nov 2015 06:00
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Electrically speaking, this thread just blew some circuits. The wealth of knowledge here is overwhelming at times - this is really directed at those without electrical skills, like myself. While, I have learned a lot from this site, these kinds of threads just highlight how much there is I don't know and trust me, there isn't room in my brain cup for all of this....what if I lose a cocktail recipe? I can always hire an electrician, not everyone, hired or otherwise, can make a good drink Priorities my friends, priorities. Also, it is helpful to know how to make drinks and food for the friends with electrical skills that can come and help as well...lol...lol.

Rowjr
Member
# Posted: 9 Nov 2015 17:37
Reply 


I put in a burial service entrance with a 200 amp service 60' for less than $600.00

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