A welding wire feeder comprising: a welding wire feed drive configured to drive welding wire towards a welding application; wire feed control circuitry coupled to the welding wire feed drive and configured to control the drive of welding wire towards the welding application; power conversion circuitry configured to receive input power via a power cable from a welding power source and to convert the input power to controlled waveform welding output; welding process control circuitry coupled to the power conversion circuitry and configured to provide control signals for conversion of the input power to the controlled waveform welding output; and a process operator interface coupled to the welding process control circuitry and configured to permit operator selection of a controlled waveform welding process, characterized by communications circuitry configured to send and receive command or feedback signals over the power cable, a power relay configured to receive input power via the power cable from the welding power source and to close to convey the input power to the power conversion circuitry; bypass circuitry coupled in parallel with the power relay and configured to carry the input power during opening and closing of the power relay; the welding process control circuitry being coupled to the power relay and the bypass circuitry to apply control signals to the power relay to close to establish a first current carrying path of the input power to the power conversion circuitry through the power relay, and to apply control signals to the bypass circuitry to close to establish a second current carrying path of the input power to the power conversion circuitry through the bypass circuit in coordination with closing and opening of the power relay. a welding wire feed drive configured to drive welding wire towards a welding application; wire feed control circuitry coupled to the welding wire feed drive and configured to control the drive of welding wire towards the welding application; power conversion circuitry configured to receive input power via a power cable from a welding power source and to convert the input power to controlled waveform welding output; welding process control circuitry coupled to the power conversion circuitry and configured to provide control signals for conversion of the input power to the controlled waveform welding output; and a process operator interface coupled to the welding process control circuitry and configured to permit operator selection of a controlled waveform welding process, characterized by communications circuitry configured to send and receive command or feedback signals over the power cable, a power relay configured to receive input power via the power cable from the welding power source and to close to convey the input power to the power conversion circuitry; bypass circuitry coupled in parallel with the power relay and configured to carry the input power during opening and closing of the power relay; the welding process control circuitry being coupled to the power relay and the bypass circuitry to apply control signals to the power relay to close to establish a first current carrying path of the input power to the power conversion circuitry through the power relay, and to apply control signals to the bypass circuitry to close to establish a second current carrying path of the input power to the power conversion circuitry through the bypass circuit in coordination with closing and opening of the power relay.