Quickly find the exact diagram you need by part number or series, including common brands like Allen-Bradley, Eaton, and Schneider. Step-by-step guides for 3-phase, single-phase circuits. PDF. Hey, in this article we are going to see proper electrical contactor connection and wiring diagram for normal operation, star-delta starter, motor control, light control, etc. The wiring diagram of a contactor is important as it shows how the device is connected to the power source and to the load. Run all input and output wires to the contactor. We are guided by our commitment to do business right, world's most urgent power management challenges.