The book says not to run the switch off track power if using TMCC because of the constant 18 volts to the track. Accoding to the TMCC book it's because the bulbs will burn out. The switches have 18 volt bulbs in them and I've tested the switches with the 18 volt track power and they work. Aside from the bulbs is there any reason why I should only use 12 volts? Is anyone using 18 volts? The switch manual says nothing about what voltage I should use.