In modern practice, the supply and return wires both arrive at the first switch, where the supply is connected to one of the two switching wires ( hot / red ); the return wire is carried inside the same multi-conductor cable to the distant second switch.
22.
In modern practice, the supply and return wires both arrive at the first switch, where the supply is connected to one of the two switching wires ( hot / red ); the return wire is carried inside the same multi-conductor cable to the distant second switch.
23.
A European device would expect one live and one return wire, like a North American 120 V outlet, so the regulations would be different regarding safety insulation . ( This is all in addition to the safety ground ( earth ) wire . ) Outlets for 3 phase power also exist but are not found in homes.
24.
In 1891, 1892, and 1893 demonstration lectures with electrical oscillators before the AIEE at Columbia College, N . Y . C ., the IEE, London, the Franklin Institute, Philadelphia, and National Electric Light Association, St . Louis, it was shown that electric motors and single-terminal incandescent lamps can be operated through a single conductor without a return wire.
25.
Rather than run an entirely new set of wires for this one device, I will just tap off the supply wires of those two circuits and bring them together for this one device . " This method of wiring does work and it reduces the amount of wire used, but it makes electrical problems very hard to find and fix, with ( possibly undocumented ) wires going all over the place within the walls and ceilings, to whatever was the most expedient supply or return wire at the time of installation.
