The minimum size EGC run with three 350 kcmil conductors is what size?

To determine the minimum size Equipment Grounding Conductor (EGC) when running conductors, it's essential to refer to the National Electrical Code (NEC), which provides guidelines based on the size of the conductors being used. In this case, there are three conductors, each of which is 350 kcmil.

According to NEC Table 250.122, the minimum size of the EGC correlates with the rating of the largest ungrounded conductor. For conductors sized at 350 kcmil, the NEC specifies that for a three-phase system, the minimum size EGC would be 4 AWG if the conductors are copper and 6 AWG if they are aluminum. However, since copper is typical in these calculations, when you run three conductors of 350 kcmil, it confirms that a minimum EGC of 4 AWG is necessary to safely accommodate fault currents and ensure proper grounding.

Choosing 4 AWG as the minimum EGC provides assurance that the grounding will be adequate to protect the system and any personnel working on or near the electrical systems from faults or failures. Thus, based upon the NEC guidelines, the minimum size EGC when using three 350 kcmil conductors