In which systems is an equipment grounding conductor always required to be installed within the raceway(s)?

The requirement for installing an equipment grounding conductor within raceways applies specifically to both nonmetallic raceways and isolated ground circuits.

In the case of nonmetallic raceways, while the raceways are not inherently conductive and do not provide a grounding path, the inclusion of an equipment grounding conductor is essential for ensuring that any fault conditions can be safely managed. This conductor provides a pathway for electrical fault currents to return to the ground, minimizing the risk of electric shock and enhancing safety.

For isolated ground circuits, the equipment grounding conductor serves a critical role in maintaining a low-impedance ground reference for sensitive equipment. This is especially important to prevent noise and interference in circuits used for sensitive electronic equipment. Having a dedicated equipment grounding conductor ensures that any stray currents can be effectively and safely redirected to ground, maintaining the integrity of the circuit.

Therefore, in both nonmetallic and isolated ground circuits, the inclusion of an equipment grounding conductor within the raceway is a critical safety measure to protect both equipment and personnel from electrical faults.