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.
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.