Which statement correctly differentiates a fused disconnect from a non-fused disconnect?

• A. It is rated for higher voltage only.
• B. Fused disconnects interrupt current under load; non-fused do not.
• C. Non-fused disconnects provide current interruption via mechanical means; fused do not.
• D. Fused disconnects provide current interruption via fuses; non-fused disconnect only provides isolation.

Answer: (D)

The main idea is how the current is actually interrupted. A fused disconnect includes a fuse element that will melt open when the current exceeds its rating, so it can stop current flow even if the circuit is closed—it provides both isolation and overcurrent interruption. A non-fused disconnect is just a switch that physically separates the conductors to provide isolation, but it does not interrupt current by itself and is not intended to clear faults.

That’s why the statement describing current interruption via fuses in a fused disconnect and isolation-only function in a non-fused disconnect is the best answer. The other options don’t capture the essential difference: voltage rating alone doesn’t define the distinction, and non-fused disconnects aren’t designed to interrupt current mechanically in a safe, controlled way.