I am in the process of adding a new bathroom which will include a spa tub. I have run two circuits to the tub as required, a single 15 amp using 14/2 wire and a double 15 amp circuit using 14/3 cable. IN addion I ran a single 20 amp circuit fed by 12/2 NM cable to the main potion of the bathroom. My understaning is that the 12/2 curcuit is sufficient for a single didicated bathroom with 2 receptables, an exhaust fan and a lighting. Is ther anyone that can confirm this?