What is the recommended practice when isolating equipment enclosures from metal raceways?

The recommended practice for isolating equipment enclosures from metal raceways is to use listed nonmetallic fittings. This practice is essential as nonmetallic fittings provide a separation between the metal raceway and the enclosure, preventing any unintended electrical contact, which could lead to grounding issues or potential safety hazards.

Using a listed nonmetallic fitting ensures that the fitting meets safety standards and is designed specifically for this type of application. It helps maintain the integrity of the grounding system and minimizes the risk of electrical faults. Nonmetallic fittings also contribute to reducing the chances of electromagnetic interference and corrosion that might occur over time with metal fittings.

In contrast, utilizing grounded fittings or leaving them unconnected could create unwanted connections or pathways for fault currents, which contradicts the objective of proper equipment isolation. An insulated grounding method may not be suitable in all situations where effective isolation from metal raceways is required.