Temporary Electric To Shed Questions

GregJ · Dec 1, 2003

A "fish tape" can be used to pull wire through empty conduits. It's a stiff, hard flat wire that comes on a spool. I have seen them 250ft. long. I always leave a length of poly twine in the conduit for future pulls.

Greg

SPIKER · Dec 1, 2003

Like others said, code does say to use clear markings for underground electrical service burried 12" above the wire, and wire should be 24" under ground if only burried in dirt, 18" if you use a concrete pour over cover, with marking above that at 12". conduit is very nice, like others said, use cloth or baggie and vacume to blow or suck rag/bag and string through and then pull a light cable as a wire pulling device theough a "sacrificial wire" can be used and then pull all other wires using it. roll up at one end and leave it there for next time... lots of ways to do things not all are wrong or right.

Mark M /forums/images/graemlins/smile.gif

Junkman · Dec 1, 2003

Call an electrician and let him do it????? /forums/images/graemlins/blush.gif December 1st starts my sarcastic month of posting.... January will be saccharine sweet!!!! /forums/images/graemlins/wink.gif

BIGUN · Dec 2, 2003

I wired the shop at my previous residence for power using a #6/3 w/ground underground cable. These are made to be buried directly in the ground without conduit. This was a 220-volt, 50 amp circuit feeding a breaker panel mounted in the shop. From there you have the option of several 110 or 220-volt circuits providing enough juice to even run a nice compressor in your shop. Smaller gauge underground cables are available if you are sure you won’t need more power in the future.
Advantage: cheaper, faster and lots less work than conduit.
Disadvantage: can’t run other wires in it like conduit, not much protection from gophers if you have them on your place. (There are some metal clad underground cables that offer more protection from digging and gophers but they would probably be more expensive than using the PVC conduit.)
I don’t know if this meets code in your area but it worked great for me. /forums/images/graemlins/wink.gif
I understand the phone companies use a high tech version of the "red buried wire marker tape" over their fiber optic cables. It is a signal wire that when broken sets off an alarm at their office. They really burn the road up trying to get there before Mr. Backhoe slices through thousands of their fiber stands. /forums/images/graemlins/smile.gif

Junkman · Dec 2, 2003

Here in the Northeast, we have "Dig Safe" .... you call an 800 number before you dig and they will mark out where the cables and other utilities are located. If you dig and hit one after they mark out where not to dig you are safe. If you don't heed they markings and dig up a utility wire, you are in deep trouble financially and legally. Occasionally, they do not mark every area of potential problem and someone slices through a telephone cable that was not marked on the maps...

MossRoad · Dec 2, 2003

Using the shop vac to suck the mouse through the conduit works easier than trying to blow it through( at least for me, it did). I use a chunk of foam rubber and some twine. Then use the twin to pull in a rope. Then use the rope to pull in the wire. Pulling lubricant also helps a lot.

 But if there were already wires in it, and I wanted to add a wire, that would be more difficult it seems. I guess one solution would be to always pull a string thru with every wire, and leave that string in place for future wire pulls. Is that the trick? 

It can help, but if you pull the string through with a bunch of wires, it can wrap around the wires. Then, the next time you pull wires through, the wires can get hung up on each other and the friction can wear off the insulations and the wires can then short out. That is another good reason to use pulling lubricant. Especially on the second and any more pulls of wires that you do afterward.

It is also a good idea to oversize your conduit. It may seem like a waste, but the larger conduit doesn't cost that much more, and it is certainly cheaper than trenching a second run a few years later. I think it is wiser to plan your electric needs for your outbuilding and run a sub panel to each one. A small building can get by with one circuit. I was told by our electric inspector that I could run one circuit to any outbuilding from the main panel in the house and be OK. However, if I wanted 2 or more circuits in an outbuilding, code required a sub panel in the outbuilding. The purpose of this was to eliminate multiple paths for electricity to the same location. Helps avoid people thinking they've turned off the power to the garage, only to find out they only killed one of the circuits and then getting bit(or worse). It is a safety thing and it makes sense to me.

I ran two runs of conduit from my house to my big garage. One was 2" conduit and the other was 2.5". The larger one has the electric for the sub panel in the garage and the smaller has 3 coax, two cat 5 wires and a pull string for later. The larger conduit sure was nice when pulling the heavy wires for the sub panel. The wires from the house go into a disconnect box, then into the sub panel. This is nice because I can kill power to the garage from the garage and then be able to open the sub panel without fear of someone turning on the breaker in the house.

TheKid · Dec 2, 2003

( How do you pull a wire thru a 75' conduit? )

I always run a string through each section of conduit when I install them. Then when I pull wires I also pull another length of string with the wires so I have something to pull more wires later.

CTyler · Dec 2, 2003

( How do you pull a wire thru a 75' conduit? The idea of the conduit for future flexibility seems like a great one, but how do you take advantage of it without a really long snake? )

I have a fish tape to run through it. You can buy blow fly's etc. or make a mouse out of whatever you have handy with some twine fishing line etc.. You just need something lite to shoot/suck through there. Then leave a small rope for future pulls. Use lube as well. You might get by without it but its' just easier to pull using it.

This sounds harder than it is. The electrical conduits use sweeps instead of 90's. So everything usually pulls ok. Now, there is a 90 going into the house from the pipe out of the ground. This has a plate you take off so you have a straight shot down the conduit. Then you leave a loop and feed the rest through to the house and put the plate back on again. The conduit into the house is all of 12-14" long.

Ender · Dec 2, 2003

It appears you have made your decision to run a temp wire overhead. If that is the case you should remember that those little block heaters draw a fair amount of current, especially when first plugged in. Plus you are nearly 100 feet from the outlet. You need to size your extension cord accordingly. A cheapo Home Depot 100 foot cord with #16 AWG wires will get hot. Depending on the size of the block heater it could get very hot. Hot enough so that the wire ties you are using to hold the cord to the rebar actually cut/melt into the insulation.

Your best bet is to get some outdoor/in ground #10 two wire with ground and make your own cord. It is stiff, does not roll up well in the summer when not in use, but is weather tough. About 50 bucks at Home Depot for a 250’ box.

bcarter · Dec 2, 2003

I have never heard of or seen "red buried wire marker tape". Can you tell me a little more about that. It sounds like it makes great sense. I have a neighbor that just put in a couple of ponds with a connecting stream. He has buried more wire and plumbing in his backyard than you can imagine. I dug the ponds and stream and a few of the trenches for him and then a contractor took over. Nothing is marked and he has no markers or photos. I'd be afraid to put a shovel in the ground in his backyard now. 

Just make sure that you bury the tape about a foot closer to the surface than the conduit/wires/etc. As you are digging, you want to hit the tape BEFORE you hit the wire! Digging a foundation for my neighbor's garage I hit the conduit that carried the wires for his guest house. The folks that installed this originally had used the warning tape, but wrapped it around the conduit! It looked very nice hanging from the piece of conduit that I pulled up. /forums/images/graemlins/frown.gif