I have approximately 85 ft run between emergency generator and ats switch. 5 ft buried, then up exterior wall then through attic then down exterior wall to ats panel. I intend to use #1 awg 3 conductor SER with ground but not sure of the rated heat and if #1awg is correct.

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    What size is your generator? – Johnny Aug 30 '16 at 23:59

200 amps will require 3/0 copper or 4/0 aluminum we would need to know how heavily loaded the circuit is expected to provide the correct wire size & for voltage drop.calculator This is easy to use code requires less than 3%. Put in your voltage 85' and expected full load.

  • Unless he has a 48KVA generator feeding his 200A transfer switch, the protection on the generator circuit is likely less than 200A, so the generator feed into the ATS doesn't need to be sized to carry 200A. I'd be surprised if it's over 20KVA, which would have 100A protection, 16KVA would be 65A. – Johnny Aug 30 '16 at 23:58
  • The wire size has to be sized to the generator that's why I gave the size calculator and mentioned the load since nothing other than the size of the ATS was given. In my experience that is a unusually large ATS for a home. but I have installed up to 65KVA generators at private residences. – Ed Beal Aug 31 '16 at 12:58
  • The ATS is rated at 200 amp, the generac model is 6551 and a 22kw whole house generator. If I am correct, the code should require 125% of The output which is approx. 85 – Stuart Onsrud Sep 1 '16 at 1:20
  • 22kw / 240= 91 x 1.25=115 amps 1/0 copper – Ed Beal Sep 1 '16 at 9:09

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