I think in Mexico its ok to use #14 for a 200 amp service as long as you use white pipe.
ROFLOL!!!
My favorite Mexican wiring method is they will grease a piece of garden house, and put in a concrete pour. After the concrete cures a bit they pull it out (so they can re-sue it), and there you have it, a custom concrete wireway.
Back on topic:
Take a look at NEC 2005 310.60 (C) Engineering Supervision.
Under engineering supervision, conductor ampacity shall be permitted to be calculated by means of the following general formula.
[formula]
Basically if you have the engineering wire specs, excel, and can get the PE for the project to sign off on it, then you can pretty much throw T31016 out the window.
Using that formula for some wire manufactures 54A with #10 AWG THHN does not sound to far off.
Granted it won’t happen in general construction here in the US for #10, but there have been times when I have used it for special circumstances in installations that access or space made it a viable solution. Like an under slab feeder for a remodel that was too small for the new service in an existing 6 story building.
