use 422 and 210 for rating limitations and even in 430.24 for motors and other loads exception 3 says if the circuitry is interlocked so as to prevent operation of selected motors or other loads at the same time------ that tells me this is not a new idea for a device to provide interlocking
several sections use interlocking to allow separate loads on one circuit 220.32(C)(3), 440.34, 440.62(C)
