white as hot

I was curious, where in the code does it allow me to mark the white as hot in a 12-2 w/ground MC cable? I am wiring a commercial ice machine that needs 208 volt single phase 2-wire circuit with ground. I wire A/C units with 12-2 and 10-2 romex and mark the white red to give me 2 hots for 240...

Hello All, I am new to this forum and this may be a dumb question but here goes: If I am wiring a 208 volt 3 phase piece of kitchen equipment that pulls 33 amps and will run more than 3 hours (continuously) I multiplied by 125% which is 41 amps so I sized my breaker to a 45 amp 3 pole and will...