Careers: Engineering & Electrical Trades/Wire return system
I'm having a hard time trying to learn the main differences in a 3 wire return call system vs a 4 wire return call system. Google isnt helping very much. As far as i can tell the only difference is the wiring. The only advantage on a 3 wire i can see is you use less materials possibly. Could you please explain this?
Need more info. A three wire return call system has one battery, two SPST pushbutton switches, two bells, and a three wire cable between the two locations. It can be changed to use only two wires between locations (i.e. a two wire return call system) if the switches are changed to SPDT. But I'm not sure of what you would call a 4 wire return call system. Does it have more than two locations? Or maybe more than two bells (or lamps, etc.) Do you have a schematic?
Hope this helps!