A testing apparatus for testing a welding apparatus is disclosed. The testing apparatus includes a receptacle, a fault indicator, and a power supply. The receptacle includes a grounding socket and a plurality of power sockets. The power supply is electrically coupled to the grounding socket, the fault indicator, and at least one of the plurality of power sockets. When a plug of the welding apparatus is matingly coupled to the receptacle, the fault indicator indicates whether an electrical resistance between a grounding prong of the plug and at least one of a plurality of power prongs of the plug is below a predetermined threshold.