A welding wire feeder includes a welding wire feed drive configured to drive welding wire towards a welding application, wire feed control circuitry coupled to and configured to control the welding wire feed drive. The welding wire feeder includes power conversion circuitry configured to receive polarized input power from a welding power source via input connections with defined polarities and to convert the polarized input power to welding output, sensing circuitry configured to detect the polarity of the polarized input power when connected to the input connections, and welding process control circuitry. The welding process control circuitry is coupled to the power conversion circuitry and the sensing circuitry. The welding process control circuitry is configured to provide the polarized input power to the power conversion circuitry only if the polarity of the polarized input power corresponds to the defined polarities of the input connections.