YIKES! If it's illegal I'm sure there is an important safety concern. So I'm back to tandem runs of 12/2 or a multiwire circuit with 12/3 (with hots on opposite busses). The multiwire was the original plan, but I'm afraid of having 240v. potential in the control box which coordinates the two motors. It's a Jason whirlpool tub, and the installation manual is pretty detailed, except that it just calls for two separate 120v. circuits for the two motors, with GFCI protection on each circuit. No mention of concerns about which buss the circuits are on(would the correct term be "phase" for distinguishing voltage from one buss or the other? I do understand that we're talking about single phase, 3-wire power in this application). The multiwire setup seems the most efficient...I'll call the OEM again tomorrow to see if I can get someone on the line who knows whether the multiwire layout will harm the control boxes. Thanks again for the heads up on the buss issue for multiwire circuits
skintdigit