Running electric power to the dock

[Bigbartguy]

hi folks

I'm looking at running electric power from the cabin down to our dock. Can anyone give me an idea of how I should do this? I dont need to be completely 'up to code' but want it buried and am wondering what kind of wire to use and does it need to be encased in anything? The distance is about 100ft.

any other suggestions are welcome also!

thank you

Tim

[Slyster]

I did something like this to a greenhouse in my backyard once. You can buy wire that's REALLY tough at Menards (or anywhere really) that is meant to be burried.. I just put it down around 6" (very flat lawn) but perhaps deeper? Then you can get water tight outlets and boxes. Was cheap and easy but probably NOT to code!

[Eric Wettschreck]

If you want to bury it, not in conduit, you can use "USE" wire. (Underground service entry)I believe THHN wire can be buried also, but you may want to check on that one. Both types of wire can be purchased from Menards. I'm thinking THHN will cost less than USE.

Coming out of the building it should be in Sch 80 conduit, and stay in conduit to about 12" underground. Then, make a loop in the wire about 16" in diameter to allow for movement when the frost comes.

At the dock do the same thing. Loop the wire underground, then run it through sch 80 conduit while still underground, and run conduit to where you want outlets and such. Use outside rated boxes and outlets and you are straight up money.

[Dave]

Code might be burying the cable at 18-inches. You must use a GFI outlet or breaker, too.

[snowman1251]

You can run "UF" wire, 18" underground with a 12" loop in the ground where you go into the ground and where you come back out, put in conduit with a bushing on the bottom and a weather proof box on the top to get it out of the ground, make sure you use a ground fault breaker in your main breaker box for this circuit , you should be safe this way

[JohnMickish]

You will need to do this to code or somebody will probably get killed.

Table 300.5, column 4 of the 2005 NEC (National Electric Code) states that a residential branch circuit rated 120 volt or less with GFCI protection an a max of 20 amps must be a minimum of 12 inches under the ground.

If this was my intallation I would run 3/4" PVC conduit SCH40 from the house to a waterproof in ground J-box close to shore, then switch to raintight/sealtight/carflex to run along the underside of the dock, with weatherproof boxes for the recepticle with GFCI.

You can run UF or USE cable direct bury but you run risks that way. A loop is not required but not a bad idea if you go the direct bury route

This is one area I wouldn't skimp on due to the high water content and the very good ground path created by the water. 120V will kill. It only takes 8 milliamps (.008) to put your heart into defibrilation and you have the potential for 20 amps here.

The main reason I would run it in conduit at a lake (or a backyard) is that tents get set up and other stakes get driven into the ground. How crappy would you feel knowing you saved a couple hours of time and maybe a hundred bucks but put someone in the hospital? There is a reason for these codes, and they are all writen in blood.

How far is it from the house to the shore? Anything over 125 feet I'd recomend running #10AWG to help your voltage drop problem. The trick thing to do would be to run two conduits down from the house, one for power and the other for cable/phone. Think about it.

[Dave]

The inspector I had two years ago wanted to see loops. Also, that's why he wanted the cable down 18-inches. Also, for code, before burying the cable, I had to lay a red electrical hazard ribbon (it's the same width as the yellow caution ribbon I'm sure you've seen) on top of the cable.

[Bigbartguy]

I'm going to run it 'near' the dock and use an extension cord whenever I need to use it on the boat. thank you for everyone's suggestions. I definitely dont want anyone getting killed over me saving a couple of hours!

[JohnMickish]

300.5 (D)(3) Service Conductors. Underground service conductors that are not encased in concrete and that are buried 18" or more below grade shall have their location identified by a warning ribbon that is placed in the trench at least 12" above the underground installation.

That is the rule for service conductors (feeders) and it's a good one but it does not apply to a 20 amp GFCI protected residential branch circuit.

300.5 (J) deals with "S" loops in the ground for frost movement. When you use direct bury cables like a service latteral (underground feeders going to a residential meter) you would you would put the loops in right next to the house but if run in conduit the entire length you wouldn't need to do that.

Different rules for different situations. I guess that is why the code book is 737 pages long.

Good luck and be safe. Use a very good, high quality extension cord if you go that route. Use a cord designed for winter use, they have a tougher jacket made with more rubber and less plastic.

[sparkyaber]

mnfishinguy, you need to know the inspector in Anoka county, he can be a little hard on homeowners.

[JohnMickish]

Sparky, does he get a little carried away? Some of the inspectors I know are harder on homeowners than on us. I don't know if they are trying to send a message that most (not all) homeowners really shouldn't be doing it themselves.

[sparkyaber]

you got it, my friend that is a 292'er, wired his house and happend to forget to tell the inspector what he did for a living. This guy was really giving him a hard time (almost threating him) until my buddy told him what he did. After that he really let up on him and finished the inspection. I wired my house and he wanted me to be there while he was there, until I told him what I did for a living, then he was fine- I have heard other stories about him. Lets just say he likes his job.

[JohnMickish]

Funny how that works. How many times have you recieved your sticker before the job was even done??

[Macgyver55]

I don't know if its the same inspector or not, but when I wired my house 17 years ago the inspector was a really nice guy. He actually gave me the pass sticker on a promise that I would correct one problem. (Which I did) He also complimented me when he said I can sure tell you are not an electrician because "this job looks too good. I wish more of them looked like this"

[sparkyaber]

You do have a different inspector in Coon Rapids- He is a great guy. He is acctually a friend of mine's father-in-law. He is pretty easy goin'.