Which of the following metal parts shall be protected from corrosion?

All metal components that are part of wiring systems, especially those made from ferrous metals (which contain iron), are susceptible to corrosion when exposed to certain environmental conditions. This corrosion can lead to compromised structural integrity and functionality of electrical systems.

Protecting ferrous metal raceways, elbows, and boxes from corrosion is essential in maintaining the safety, reliability, and longevity of electrical installations. Each of these components plays a critical role in housing, protecting, and supporting electrical wiring.

By ensuring that all of these parts are adequately protected—whether through galvanization, coating, or using corrosion-resistant materials—one can prevent issues like rust, which can contribute to electrical faults, short circuits, or even system failures. Thus, the answer encompasses the need for comprehensive protection across all mentioned ferrous metal components.