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I’m stubbing power(3 # 10 wires in 3/4 plastic)and water (1″ sch 40) around the perimeter of my yard in Bay Area.About 150′ total run from the house supply. Two questions
1. Is the #10 good for general use(with respect to voltage drop), for a set of low voltage lights and an occasional power tool or blender.
2. How should they be run in the trench, how deep?, side by side? or elec lowest and water 6″ above??
Oops there’s a third
3. Plastic elec pipe instead of thinwall conduit? It will be in a planting bed that is hand dug and probably not disturbed much. Either way covered with 3/4 rock and then soil.
thanks for the advice.
h
Replies
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# 10 wire will be fine for your intended use. Use plastic conduit if you are going to use conduit and bury it at least 18" deep. Pull the wire one section of conduit at a time and apply cement only to the male end of the pipe. The wire can be in the same trench as the pipe unless you are concerned about having to tap into or repair one or the other down the road and don't want to worry about damage to the other pipe.
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Put the water pipe below the electrical line (the idea is that if the water leaks, the electrical wires won't be immersed in saturated soil). Definitely plastic conduit instead of thin-wall metal. Use compressed air to blow your pull string through. Or consider direct burial cable. Looks like romex but there is no kraft paper filler. The outer insulation is continuous around the inner insulation. What city and are you in the flats or the hills of the Bay Area? Generally the hills have more gravel and cobbles. But if you're in the flats, you've likely got fine-grained soils and are an ideal canidate for use a walk-behind trencher. I've put in 400 feet of water and electrical lines in a day in a Hayward (flats of) backyard. If you're going to get it inspected, ask what depths your inspector wants. It varies with whether there will ever be vehicle traffic and whether it is paved or not. -David
*I'm guessing your trench won't be tremendously deep, but as a safety concern, you may want to pick up a roll or two of the 1" plastic orange surveyor's "tape". After the water and elec lines have been put down and the trench partially backfilled, lay the orange tape out in the trench a few inches below the soil surface. Any future digging in the area, the digger will hit the tape long before the lines and be forewarned as to what lays below.Just an idea for those who come after you...
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I just completed a similar project (for occasional power and yard lights, too!) I put in one trench a inch and 1/4 poly water line, a 110 volt UF #12 cable, a #14 guage UF which I'm using as my low voltage cable, 2 7 conductor sprinkler control wires and then for good measure I put a 1 and 1/2 inch pvc pipe with a rope through it in case I wanted to pull anything in the future. Where the electrical is in *any* area where we are going to have a flower bed, etc., I put it in 3/4 plastic conduit (the electrical grey stuff). I cable-tied and bound all of the wires and placed them beside the pvc and above the water line. I've got everything hooked up now except the low voltage line for the lights, and it seems to be working great. It is sure nice to have 110 to run the dremel tool with a carbide grinder bit to rout out the sides of the sprinkler box where the pipe runs in and out! --Ken
*Oh; one other thought---make damn sure you have your electrical line on a GFI circuit, and that the line for your low voltage is also GFI protected.... --Ken
*Thanks guys, all great tips.h
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If you are running conduit the romex is not necessary, and the UF-B is definete overkill. You can legally run THHN (stranded) copper conductors and pull 6 conductors in the same space for the same cost as UF-B. The THHN will also make it easier to cut circuits in later. When going under beds, I buy scrap 4" or better pipe, slit it lengthwise, and lay the half over the top of the buried stuff to protect it from shovels. Definetly add the marker tape, I put it about 4 inches from the top.
-Rob
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thanks again, cleared up some of the details that will make this a long term solution.
I'm on it this weekend!
h
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If you don't have a compressor, "suck a mouse" thru the conduit. A mouse being a bit of rag or fluff, tied to a string, sucked by a household vacuum.
#10 could actually be UNDERSIZED depending on the load in watts. With low voltage, especially 12 volts, you can get a lot of amps for not that many watts. W=EI. 30 amps x 12 volts = 360 watts allowable?
Some of the low voltage lighting kits have transformers that handle only 80 or 100 watts. You'll want to do the calcs before you bury the wires.
By the way, I ran 12volts AC to my shed, and installed a surface mounted switch and a normal porcelan lamp holder and a 75 watt 12 volt bulb. The bulb cost $5.00, but are used in RV's. Eliminated the need for a electrical permit (hopefully legal).
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I'm stubbing power(3 # 10 wires in 3/4 plastic)and water (1" sch 40) around the perimeter of my yard in Bay Area.About 150' total run from the house supply. Two questions
1. Is the #10 good for general use(with respect to voltage drop), for a set of low voltage lights and an occasional power tool or blender.
2. How should they be run in the trench, how deep?, side by side? or elec lowest and water 6" above??
Oops there's a third
3. Plastic elec pipe instead of thinwall conduit? It will be in a planting bed that is hand dug and probably not disturbed much. Either way covered with 3/4 rock and then soil.
thanks for the advice.
h