A ZSI testing apparatus includes a fault generation circuit, a plurality of cable assemblies coupled to the fault generation circuit, wherein the cable assemblies are structured to be selectively coupled to selected circuit interrupters, a human machine interface, and a controller coupled. The controller is configured to: (i) selectively cause a fault current to be provided to a number of the cable assemblies, (ii) receive an input from each circuit interrupter that is coupled to one of the cable assemblies, each input being indicative of a trip signal output of the circuit interrupter, (iii) determine based on the received inputs (a) that an error has occurred with respect to operation of the circuit interrupters and (b) a recommendation for fixing the error, and (iv) cause an output indicative of the error and the recommendation to be provided on the human machine interface.