I am building a 16x20 shed for my woodworking projects. It is about 80 ft from house. I am attaching power to existing electrical panel on outside of house. What size wire do I need to run to shed?

I have a 100a main breaker panel in the shed, I am thinking with a 220 service and the tools I will be using are a medium table saw (110), planer (110), etc. I need to bury it with plastic grey conduit 18 in in the ground (min).

What do you guys think?

  • 1
    This same basic question exists many times. Did you search? – Tyson Feb 6 '18 at 5:43
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    Dozens. The key is speccing your service size, as you are thinking in volts, and that's a given. Think in either amps, or watts/VA. (VA = Volts x Amps, watts is very similar to VA, and voltage is now 120/240, it's been bumped). One more thing: Don't forget the dust collector. Everybody forgets the dust collector, it will need its own circuit, it can't share with the saw. On the big tools, get the motor numbers if you can, focus on amps and VA. – Harper - Reinstate Monica Feb 6 '18 at 7:36
  • My opinion is 60 amps is a minimum for a shop. 100 a service is tiny for a main panel, If you have all gas heat, oven,cook top and dryer you may be ok but in most cases a larger service mat be needed, at work 99% of the time I use rigid metal conduit above and below ground, at home I will use direct bury, I know where the lines are and they are deep enough I have never had a problem, the distance won't be a problem with voltage drop at 80' even at a larger panel than I suggest. – Ed Beal Feb 6 '18 at 8:43
  • 60A is a good service size, the subpanel must be at least that, and should have enough spaces for all your tools, a 125A/20space panel is NOT excessive for a wood shop. You'll go through it lickety split if you get 240V tools. – Harper - Reinstate Monica Feb 7 '18 at 1:00

I googled "amperage distance wire size" and clicked on the first wire size calculator that came up.

For 240 volts at 100 amps, at a length of 80 feet, it recommends 1AWG copper.

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  • For that length of RUN go with ALLUMINUM Wire. it will save you money (even with the larger AWG wire required for Al). – mark f Oct 13 at 15:26

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