How does electrical locomotives works in a single wire supply for any wire connections two wires are required but in traction electical engines are touching only one wire. Pl explain me in details?
Electric trains typically receive their power either from a "third" rail using a contact shoe, which is mounted on insulated supports on the ground parallel to the steel rails the train wheels role on, or from above from wires that are stretched over open areas above the tracks. This system is called a "catenary" system. On top of the train is an accordianed contact shoe that rubs against the overhead wires. This sytem is only used outdoors. As you stated in your question, you need two conductors to make a circuit. The second "wire" in these train systems is the steel running rail. One or more of the steel rails is connected electrically to the source. It really is a two wire supply, but the second wire is hard to notice.