What type of sheathing is required for cables that contain conductors of intrinsically safe circuits?

Cables that contain conductors of intrinsically safe circuits are required to have grounded metal sheathing or metal cladding due to safety concerns in hazardous locations. The use of metal sheathing serves to contain any fault current and reduce the risk of ignition of flammable materials in the atmosphere. This grounding offers an additional layer of protection and ensures that if a fault occurs, it will be safely diverted, minimizing the risk of sparking.

Metal sheathing effectively contributes to the safety measures already in place for intrinsically safe circuits, which are designed to prevent energy levels from being high enough to create an ignition source. By utilizing grounded metal, the cables aid in maintaining the integrity of the wiring systems in potentially explosive environments, thus ensuring compliance with safety regulations and standards.

Other types of sheathing, such as plastic, insulated, and non-metallic sheathing, do not provide the same level of robust protection against electrical faults in hazardous locations. These materials may not adequately safeguard against ignition sources that could arise from electrical failures, making them unsuitable for use with intrinsically safe circuits.