electrical arc suppression when terminals under load are connected / unconnected is provided via an applied magnetic field causing the arc path to be lengthened , with the consequences that the voltage necessary for the arc to be sustained is increased and the arc energy is decreased . in a preferred form , at least one magnet with a high permeability flux return path is placed adjacent the terminal proximity zone of initial / final touching of mating terminals . the magnetic field increases the arc length , and thereby suppresses the arc by increasing the voltage necessary to sustain the arc and decreasing the energy of the arc .