An apparatus for electrical protection of an electrical system includes a protection circuit for detecting when silicon controlled rectifier (SCR) or other control elements in an engine driven generator of a welding-type power source have failed. In such an apparatus, a shorted rectifying control element detection device has an input stage connected to an engine driven generator that supplies power for a welding-type process and a filtering stage to bandpass current signals acquired by the input stage from the engine driven generator. The apparatus further has an output stage connected to the filtering stage that at least indicates a fault condition if fundamental frequency components present in the current signals exceed a threshold.