When installing an alarm system in a building storing hazardous materials, how must the alarm circuits be protected?

To protect alarm circuits in a building storing hazardous materials, using separate threaded steel conduit is the best practice. This choice ensures that the alarm circuits are housed within a robust, fire-resistant enclosure that can withstand potential impacts, corrosive environments, and prevent the ignition of flammable materials nearby. The use of threaded steel conduit enhances the mechanical protection of the wiring, especially in environments where harsh conditions may exist due to the presence of hazardous substances.

Threaded steel conduits also provide an essential ground pathway, reducing the risk of static discharge or electrical faults that could ignite materials. In settings with dangerous materials, it's critical to minimize risks, and steel conduits help in achieving compliance with safety regulations and standards for installation in such sensitive areas.

In contrast, non-metallic conduits, flexible tubing, and PVC pipes may not offer adequate protection against the hazards present in these storage areas. Non-metallic options might not stand up to physical stress or exposure to chemicals, while flexible tubing could be insufficient for both mechanical protection and grounding needs in hazardous settings.