Which type of cable is prohibited for permanent mine wiring applications?

In the context of mine wiring applications, portable (trailing) cables are prohibited for permanent installation due to their design and intended use. These cables are specifically designed for flexible applications where they may be moved or repositioned frequently. Because of their mobility and lighter construction, they may not provide the necessary durability and protection for fixed installations that are subject to harsh underground conditions typical in mining environments.

Permanent installations require cables that are rated for continuous use in a static position, which ensures they can withstand environmental stresses such as abrasion from equipment, exposure to moisture, and chemical exposure without degradation over time. This makes the use of static cables, high-voltage cables, or heavy-duty cables more suitable for permanent wiring, as these options provide higher levels of insulation, protection, and mechanical strength necessary for safe and reliable long-term performance in permanent mine applications.