What is the minimum size of the EGC required between a 200-A safety switch and a motor with three 2 AWG conductors?

In electrical installations, the minimum size of the Equipment Grounding Conductor (EGC) is determined by several factors, one of which is the size of the conductors supplying the equipment and the overcurrent protection device protecting those conductors.

When calculating the correct size of the EGC, the National Electrical Code (NEC) provides guidelines that reference the size of the ungrounded conductors (in this case, the three 2 AWG conductors). For feeders and branch circuits, the NEC Table 250.122 specifies the minimum EGC size based on the rating of the overcurrent protective device.

For a safety switch rated at 200 amps, the corresponding minimum EGC size, according to NEC Table 250.122, is 6 AWG when the ungrounded conductors are 2 AWG copper or larger. This means that if you have a 200-A safety switch and conductors of 2 AWG, a 6 AWG ground would be the minimum size required.

Thus, the correct response aligns with the NEC guidelines, making 6 AWG the required minimum size for the Equipment Grounding Conductor in this scenario. This ensures that the grounding system is adequate for safety and proper functioning to