In Class II Division 1 locations, which wiring methods are approved for use?

In Class II Division 1 locations, which wiring methods are approved for use?

• A. II & III only
• B. I, II, or III
• C. I & II only
• D. I & III only

Answer: (A)

In Class II Division 1 locations, the wiring must be protected against dust intrusion and physical damage because dust is present and can ignite if it contacts energized conductors. The two protected wiring methods provide that level of protection by enclosing the conductors or using armored/rigid routes that prevent dust from entering and resist damage. The unprotected or open wiring method would leave conductors exposed to dust and damage, creating ignition risk, which is not acceptable in Division 1. So only the two protected methods are approved for use in these locations.

In Class II Division 1 locations, the wiring must be protected against dust intrusion and physical damage because dust is present and can ignite if it contacts energized conductors. The two protected wiring methods provide that level of protection by enclosing the conductors or using armored/rigid routes that prevent dust from entering and resist damage. The unprotected or open wiring method would leave conductors exposed to dust and damage, creating ignition risk, which is not acceptable in Division 1. So only the two protected methods are approved for use in these locations.