Plug-in multifunction tester for ac electrical distribution system

摘要

A portable tester (23) plugs into a receptacle (15) in a branch circuit (3) of an electric power distribution system (1) to verify protection against arc faults, line to ground faults and neutral to ground faults provided by a circuit breaker (11) located at a remote load center (13) or by ground fault and, or arc fault interrupters in the receptacle, and also checks for proper wiring. The arc fault detector (29) gates phased back rectified half cycles of the ac power to generate step changes in the instantaneous amplitude of current in the branch circuit (3) which mimic the repetitive striking of an arc. Preferably, only half cycles at least 60 ms apart are gated so that the user can verify the time to trip with a watch and can count the gated half cycles to trip by counting pulses generated by a light emitting diode (LED) (125) in the gating circuit (41).