You do realize your arguing this fact with an electrician? Take your house for example, 120v circuit #14 wire will carry 15A, #12=20A, #10=30A, #8=40. That same wire on a 240v circuit- #14=15A, #12=20A, #10=30A.... Are you seeing the pattern?
Borrowed from
http://www.allaboutcircuits.com/vol_1/chpt_12/3.html
COPPER CONDUCTOR AMPACITIES, IN FREE AIR AT 30 DEGREES C
========================================================
INSULATION RUW, T THW, THWN FEP, FEPB
TYPE: TW RUH THHN, XHHW
========================================================
Size Current Rating Current Rating Current Rating
AWG @ 60 degrees C @ 75 degrees C @ 90 degrees C
========================================================
20 -------- *9 ----------------------------- *12.5
18 -------- *13 ------------------------------ 18
16 -------- *18 ------------------------------ 24
14 --------- 25 ------------- 30 ------------- 35
12 --------- 30 ------------- 35 ------------- 40
10 --------- 40 ------------- 50 ------------- 55
8 ---------- 60 ------------- 70 ------------- 80
6 ---------- 80 ------------- 95 ------------ 105
4 --------- 105 ------------ 125 ------------ 140
2 --------- 140 ------------ 170 ------------ 190
1 --------- 165 ------------ 195 ------------ 220
1/0 ------- 195 ------------ 230 ------------ 260
2/0 ------- 225 ------------ 265 ------------ 300
3/0 ------- 260 ------------ 310 ------------ 350
4/0 ------- 300 ------------ 360 ------------ 405
Note that it doesn't say anything about voltage.