My home is wired the normal way with 220 and 110v It is my understanding that basically 1/2 the 110v circuts are taken from one buss bar and the other half from the second bar. 220v is supplied from both buss bars. I just purchased two PH508 Power horns and a PS561 console, along with the d/w sensors, motion detectors etc. Am I correct in assuming that all add on devices must be on the same main circuit?