NEC Article 200 provides the rules on the proper use and identification of grounded conductors. For simplicity, this part of the course will refer to them as grounded neutral conductors. There are also rules on proper termination of a grounded neutral conductor in Article 408 which covers switchboards, switchgear, and panelboards.

A grounded neutral conductor carries current as its principle function whereas an equipment grounding conductor does not. Without a grounded neutral conductor in a circuit that utilizes a neutral, the circuit will not function. An equipment grounding conductor only carries current if a fault to ground occurs in a circuit or electrical equipment.

The typical panelboard can have many grounded neutral conductors. Proper termination of each grounded neutral conductor is important since removing a neutral conductor under load can create an arc and shock hazard.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC^® edition of NFPA 70.

2020 Code Language:

200.2(B) Continuity. The continuity of a grounded conductor shall not depend on a connection to a metallic enclosure, raceway, or cable armor.

408.41 Grounded Conductor Terminations. Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.