A testing circuit assembly can include a first variable resistive load configurable for a range of electrical resistances, where the first variable resistive load is configured to couple to at least one first ground fault circuit interrupter (GFCI) breaker and a current source. The testing circuit assembly can also include a first local controller coupled to the first variable resistive load, where the first local controller controls the first variable resistive load to simulate a range of fault currents, corresponding to the range of electrical resistances, flowing to the at least one first GFCI breaker to determine at least one actual trip point of the at least one first GFCI breaker. Each electrical resistance in the range of electrical resistances can correspond to a fault current in the range of fault currents.