Which wiring methods are permitted in Class 1, Division 1 locations?

In Class 1, Division 1 locations, wiring methods are subject to stringent requirements due to the presence of flammable gases or vapors that could create explosive atmospheres. The National Electrical Code (NEC) recognizes several wiring methods that can provide adequate protection in these hazardous environments.

Permissible wiring methods in these areas include metal conduit, flexible cords, and non-metallic conduit, as each has specific attributes that can enhance safety and prevent the ignition of explosive mixtures. Metal conduit is recognized for its ability to provide good grounding and physical protection. Flexible cords may be used in certain applications where flexibility is necessary, and non-metallic conduit is also allowed for its lightweight and corrosion-resistant properties.

The inclusive nature of the options indicates that all the listed methods are compliant with safety codes when installed correctly. Hence, the choice indicating that all of these options are permitted correctly reflects the NEC guidelines for wiring methods in Class 1, Division 1 locations, ensuring versatile and safe electrical installations in hazardous areas.