Which PV isolating device is permitted?

Which PV isolating device is permitted?

• A. FUSE HOLDER
• B. circuit breaker
• C. general-use switch
• D. molded case switch

Answer: (A)

In PV installations, the isolation point for the DC source must be a listed device specifically designed for PV use, providing a clear, accessible break in the circuit. A fuse holder fits this role because it is a purpose-built disconnect that accepts PV-rated fuses, giving a visible open or closed state and reliable interruption of the PV current. When paired with the correct PV fuses, it serves as both protection and a readily accessible disconnection point at the PV source. The other options don’t meet that requirement as reliably. General-use switches aren’t typically listed for PV DC circuits and may not guarantee a safe, visible disconnection under DC conditions. Molded case switches and standard circuit breakers may not be approved as PV isolators unless specifically listed for PV use; their suitability depends on compliance with PV-specific listing and mounting requirements. Therefore, the fuse holder is the permitted PV isolating device in this context.

In PV installations, the isolation point for the DC source must be a listed device specifically designed for PV use, providing a clear, accessible break in the circuit. A fuse holder fits this role because it is a purpose-built disconnect that accepts PV-rated fuses, giving a visible open or closed state and reliable interruption of the PV current. When paired with the correct PV fuses, it serves as both protection and a readily accessible disconnection point at the PV source.

The other options don’t meet that requirement as reliably. General-use switches aren’t typically listed for PV DC circuits and may not guarantee a safe, visible disconnection under DC conditions. Molded case switches and standard circuit breakers may not be approved as PV isolators unless specifically listed for PV use; their suitability depends on compliance with PV-specific listing and mounting requirements. Therefore, the fuse holder is the permitted PV isolating device in this context.