What type/gauge wire do I need to run 200 feet from transformer to meter for 100 amp service in an out building? Is 2 inch conduit sufficiant?

  • Conduit size? Depends. How many swear words do you know? Also how many bends will there be? – Harper - Reinstate Monica May 22 '18 at 16:37
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    Check with your utility they likely have standards, in my area they requires 3” now, for 100 or 200 amp. The conduit is customers responsibility per the utilities standards and then the utility supplies and pulls the wire from transformer to meter, ask the power utility what the requirements are in your case. They likely have a booklet for this, most utilities do. – Tyson May 22 '18 at 17:37
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    Will you be laying the wire, or the PoCo? Being before the meter, it is usually their bailiwick. – Harper - Reinstate Monica May 22 '18 at 22:07
  • Who's your utility? Also, why are you responsible for this? – ThreePhaseEel May 22 '18 at 22:33

If it were feeder, you'd be required to use 1 AWG aluminum. Since you say it is a service lateral, you would be allowed to use wire sufficient for only 83% of 100 amp, or 2 AWG Al. However, given the distance involved you're probably going to want to upgrade to 1 AWG aluminum to avoid too much voltage drop.

As far as copper, you can use it if money is No Object, however normally this big stuff is aluminum and it works perfectly fine. The attachment lugs will be aluminum, so that keeps the metals the same.

You might squeeze that into 2 inch conduit if you know enough swear words! However, as a DIY person, I would much rather be pulling it through 3 inch conduit.

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