Scott,
I didn't say there wouldn't be any harmonic distortion of the wave form due to nonlinear loads, however it is my understanding that the harmonic wave forms do not add in the 120/240 single phase systems as they do in the 208y/120 volt systems, and therefore there isn't the neutral overheating problem. Even with harmonic loads, the code still permits me to say the neutral is not a current carrying conductor in single phase systems. See 310-15(b)(4)(a-c)
The copper and transformer people really do not want the industry to understand this because if we did we'd just use 120/240 volt distribution for these loads in place of oversized neutrals and expensive "k" rated transformers.
Don(resqcpt19)
