I've been working in the field for nine years, residential new construction and have never dealt with a 208 system. I've looked through the NEC for a description/explaination and did not find one. If there is article on the matter, which one, I can take it from there. If not could someone please explain this for me, thanks. The motivation for this is for two reasons 1) Common knowledge so I will know in the future and don't have to ask silly questions. 2)Will a 208v 8kva(1 or 3 phase) griddle cook(be ruined, sorry for the pun) on a 120/240V 40 Amp circuit? This question I do not know the answer to. Thanks.