What is maximum distance I can run 12 gauge wire to a shed?

[mobregon]

Hello,

Need some advice. I have a 20amp breaker with 12g/2 underground feeder wire running to an outdoor GFIC outlet. 38 feet from breaker box to where it leaves the house and then 32 feet buried 24 inches deep (no conduit) to the 20A GFIC outlet.

So from breaker box to outdoor outlet is a total of 70 feet. I want to extend this circuit to my shed by tapping off the GFCI outlet for another 65-70 feet to my shed. The new cable will also be 12/2 UF buried 18 inches inside schedule 40 PVC conduit. Once it reached my shed and I run cable inside it might be another 10 feet of internal wiring. I plan on installing 2nd 20Amp GFIC outlet > Light switch > light fixture. Main reason for this long wire run is to get lighting to the shed and also connect the occasional miter saw, circular saw and orbital sander....(of course not all at once). All these power tools draw 15amps.

I need advice if the distance from breaker to shed is too long for 12 gauge wire and also if it is safe. The total distance would be around 150 feet.
I was looking at some voltage drop calculators but not sure if I'm entering the proper input to come up with a proper calculation.

I'm DIY and have basic understanding of electrical topics. Thanks in advance for any advice/feedback/suggestions.

MO.

 

[Spoon]

Welcome to the forum mate.
The volt drop for your run of 150 feet using 12 gauge is 7.94% which is bigger than the recommendations.
This means that the items will be running below the recommended voltage.

There are some forum members that have a lot more knowledge regarding the regs in your country (I'm UK based) that can give you more info.

 

[telectrix]

the volt drop will depend on the actual current drawn as opposed to the breaker rating. you will only be using 1 power tool at any one time, so your design current may be quite a lot less than 20A. however, best to allow for 20A max. in case of increased load in the future.

 

[mobregon]

Thank you for your responses. Like I mentioned in my post, I'm mainly doing this to get a working light inside my shed to allow me to continue working at night. From time to time I will plug in my saws to cut the occasional piece of wood. At the moment I connect a 50' extension cord (it is orange but not sure the gauge of it) to the GFCI outlet I want to extend to my shed and I don't really feel my saws run any slower. The main concern I have is will it be safe to run 12 gauge UF wire inside pvc pipe and not cause the cable to get too hot due to the 150 distance. Also will the new outlet, light switch and light fixture be safe?
Thanks,
MO.

 

[Megawatt]

Hello,

Need some advice. I have a 20amp breaker with 12g/2 underground feeder wire running to an outdoor GFIC outlet. 38 feet from breaker box to where it leaves the house and then 32 feet buried 24 inches deep (no conduit) to the 20A GFIC outlet.

So from breaker box to outdoor outlet is a total of 70 feet. I want to extend this circuit to my shed by tapping off the GFCI outlet for another 65-70 feet to my shed. The new cable will also be 12/2 UF buried 18 inches inside schedule 40 PVC conduit. Once it reached my shed and I run cable inside it might be another 10 feet of internal wiring. I plan on installing 2nd 20Amp GFIC outlet > Light switch > light fixture. Main reason for this long wire run is to get lighting to the shed and also connect the occasional miter saw, circular saw and orbital sander....(of course not all at once). All these power tools draw 15amps.

I need advice if the distance from breaker to shed is too long for 12 gauge wire and also if it is safe. The total distance would be around 150 feet.
I was looking at some voltage drop calculators but not sure if I'm entering the proper input to come up with a proper calculation.

I'm DIY and have basic understanding of electrical topics. Thanks in advance for any advice/feedback/suggestions.

MO.

MOB the best way to do that is splice #10/2 romex underground approved to the # 12 and that should take care of voltage drop problem that you would have with #12

 

[pc1966]

If you are working at night and both tools and lights come from the same GFCI you might want to consider having an "emergency light" that have battery back up. Saves a breaker trip leaving you in complete darkness with power tools around!