Electrical question

[Daryl]

built a garage and had electric put in it. I have a 200amp box and am using only 80amps. My question is I have a shed abot 125-150 feet away that I would like to put lights in and maybe 1 plug in. Can I hook on to box in garage and run wire to shed? What size wire and if i run it from maybe 60 amp breaker would I lose alot of "juice" by the time it got there? I know I would have to put another box there to go back to 120, or at least I think I would. Anyway any help would be appricated.
Thanks
daryl

[egon]

Chances are you would be off running 220 to the shed and reducing it to 120 there. It will let you get by with a smaller wire size.

A 20 amp 220 breaker in garage running 12 gauge wire to box in shed with another 20 amp 220 main breaker. Then down to 120 and 15 amp breakers in the box.

Note; my electrical knowledge is limited at best. [img]/forums/images/icons/grin.gif[/img] [img]/forums/images/icons/grin.gif[/img]

Check your local regulations first.

Egon [img]/forums/images/icons/grin.gif[/img]

[Daryl]

Thanks.. Never thought of that.. [img]/forums/images/icons/blush.gif[/img]

[chadincolo]

Not true, 220 is simply 2 110 wires, so the difference between running 220 to the shed or 110 to the shed is that 220 will require a bundle with one more wire.

[egon]

Really! [img]/forums/images/icons/confused.gif[/img] [img]/forums/images/icons/confused.gif[/img] [img]/forums/images/icons/confused.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img]

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Ah, ... but here is the kicker..... [img]/forums/images/icons/tongue.gif[/img] . When you run a bundle with two hots, one neutral and one green, the neutral can do twice as much work as long as the two hots are not on the same leg. So a 220V 4-wire service to that shed will actually give him two independent circuits of 120V each. Each hot leg can share the neutral. Remember.....this would be technically a SUB PANEL, so you must also run a green to it from your 200A panel AND..... you must also split the two grounding bars in the new sub panel so that the greens go on one bar and the whites go on another. Remove any cross-connection between those bars and don't put the green grounding screw into the bar that has the whites connected to it. [img]/forums/images/icons/tongue.gif[/img] [img]/forums/images/icons/crazy.gif[/img] They make a nice bundled cable for direct burial that has red-blk-wht-grn. If you ran a number 10 cable you would be set up for 30 amps per leg. Number 12 would handle 20 amps nicely, even at that distance. If you put the lights on one leg and the plugs on the other, you'd be in great shape with #12. [img]/forums/images/icons/smile.gif[/img]

[Pat]

Egon, You had the right idea but not the proper mechanization. If you had a 2:1 transformer in the shed to make 120 VAC out of the 240VAC your wire size comments would be correct. This is the motivation behind higher voltage in electrical distribution. You can move the power (P=IE) or (P=E2/R) which shows that raising the voltage will get the power there with less loss if the wire resistance is held constant.

Said another way, higher voltage will let you move power with smaller wires. That is why the utility brings high voltage to your transformer and there drops it to 240 volts (center tapped to give you a pair of 120VAC legs.) IF they distributed 240 volt electricity across the country the wires would have to be simply ENOURMOUS!!! (and in Dave's neighborhood subject to theft.)

For the original poster... If you use large enough wires the loss can be held to any predetermined value over increased distances. Longer run...use bigger wire and the result is the same, loss wise. Pocket book will feel the difference.

Pat

[Pat]

Daryl, You need to be specific about your confusion to be able to more easily get specific help.

I reread your initial post. The size of the breaker in the "main box" has no relationship to the losses of the wire running to the second box.

You need to at least size the wire as large as the code calls for and if near the limit for the length of your run, be smart and go a size larger.

Your initial comments were right on. You run wire from a breaker in box #1 (double pole/240 volt) to power box #2 (a sub panel.)

The breaker in box #1 will limit the max current the wire to box #2 will be exposed to and prevent it being overheated, damaged and becoming a fire hazard and such. You can wire from breakers in box #2 to ouitlets, lights, and such. The breakers in the sub panel are sized for the branch circuits in the remote location, like 20 amp for a string of outlets (or even just one.)

The BEST practice is to run 3 wire with ground (a total of 4 conductors with one probably bare.) THis wire is available in "romex" to run in conduit or inside walls or with different insulation and jacket for direct burial in the ground. A downside to direct burial is gophers and such chewing on them. I recommend plastic conduit for burial to be safe.

The 4 conductor wire is used as follows: red and black are connected to the two output connections on the two pole breaker in box #1(one to each output screw.) Each of these wires feeds a "rail" or buss in box #2.

The white wire is the neutral and connects to an insulated buss/connector with a row of screws that is not electrically connected to the box itself.

The green (or bare) wire is the ground wire and connects to the other buss/connector in box #2 with a row of screws. Some boxes also insulate this buss from the frame of the box. It is OK if it is connected to the frame of the box. Here is where yet more folks may disagree... the ground buss and the neutral buss in box #2 should not be connected to each other. You can buy a box so configured or that can so so configured by removing a jumper.

I prefer having the neutral and ground separate.

Check the NEC and/or local electrical code which supersedes the NEC if there is a variance and if anything I said is not to code: 1. I'd be surprised, and 2. do what the code says instead of what I said.

You will want to drive a ground rod IAW local code and wire it to the ground buss in box #2 IAW local code.

It is possible without violating the laws of physics to light a light or run a tool at the remote site with a much simpler setup. I do not recommend it. Code will not provide for most really simple methods. Your insurance carrier would NOT be happy with you and the little gnomes (much worse than gremlins) who cause electrical problems would have a field day with you.

Warning: The following is NOT to be done, just thought about!

The simplest way to light a light or power a tool at your remote site is to run a single conductor from a breaker in your box to the remote site and connect it to the "hot" connection on an outlet. Drive a ground rod or connect to a metal water pipe and wire that to the neutral connection of the outlet. This will give you approximately 120VAC up to the rating of the breaker supplying the current. This is the cheap[est way to get remote power and SHOULD NEVER BE DONE BECAUSE IT IS DUMB!!!

It saves $ but is really really DUMB. Have I ever done anything like this or as dumb. Well yes but just long enough to survive a temporary emergency or crisis and I did not leave anything like this hooked up when not actually there on site.

I have used a few hundred feet of RG-8 radio antenna coax to send 120VAC to a remote antenna site to power my soldering gun to solder the fittings onto the coax supplying the power. Not my favorite action but if you are careful and do not leave the coax connected to power and unattended no one will get hurt and in that part of Mexico it could have taken a week to get extension cords to do the job.

Note: The simple DUMB method I described is NOT what Egon said. His way was more sophisticated, not as cheap as mine, and something I would still never recommend.

Pat

[Daryl]

Thank you.

[jml755]

------"Warning: The following is NOT to be done, just thought about!
The simplest way to light a light or power a tool at your remote site is to run a single conductor from a breaker in your box to the remote site and connect it to the "hot" connection on an outlet. Drive a ground rod or connect to a metal water pipe and wire that to the neutral connection of the outlet. This will give you approximately 120VAC up to the rating of the breaker supplying the current. This is the cheap[est way to get remote power and SHOULD NEVER BE DONE BECAUSE IT IS DUMB!!!"

Agree 100% with Pat. BTDT, back when I knew nothing about "code". I wanted to switch the garage lites on/off from our first house (many, many moons ago), so I used the neutral for the "switched" hot. As Pat said, IT WORKED. However, turning off the breaker on that circuit would make the garage lites glow! [img]/forums/images/icons/frown.gif[/img] I knew that was NOT a good thing, so I fixed it before we moved.