A Grounded Conductor is defined as a system or circuit conductor that is intentionally grounded. When something is “grounded” in accordance with the NEC^®, it is connected to ground or to a conductive body that extends the ground connection. Some grounded conductors are also neutral conductors.

A Neutral Conductor is defined as the conductor connected to the neutral point of a system that is intended to carry current under normal conditions.

Since a grounded neutral conductor is intended to carry current under normal conditions, it is required to be sized differently than an equipment grounding conductor (EGC) which is only intended to carry current during a ground-fault condition. The minimum size of a grounded conductor is determined from NEC^® Table 250.102(C)(1) based on the size of the largest ungrounded service entrance conductor or equivalent area for parallel conductors.

Sometimes the load on a neutral conductor will require it to be sized larger than the bare minimum from Table 250.102(C)(1). See NEC^® 220.61 for calculating the feeder or service neutral load.