Equipment Grounding Conductor

Equipment ground is the wire that grounds metal parts to prevent them from producing a shock- by allowing a circuit breaker to trip when a faulty wire touches metal parts and current flows through the ground wire. Because the tripping occurs instantly, the equipment ground wire will not heat up and can thus be smaller than the hot wire. Table 250.122 in the NEC shows the ground wire sizes for a given size of a circuit overcurrent device. [[Table