A DC contactor is an electrically controlled device used to switch on and off currents. DC contactors control the flow of current in a DC circuit by closing and opening internal contacts. They control much lower voltages than AC circuits and provide minimal arcing when the circuit is opened and closed. The main function of a DC contactor is simply to make and break the connection between the power source and the load. One side of the contactor is fixed and the other is movable. Once energized, the generated electromagnetic force pulls the movable contact toward the fixed contact, and once de-energized, the spring pulls the contactor apart.