Which statement about a dual-element fuse is true?

• A. Two normal one-time fuse links
• B. A thermal cutout only
• C. A thermal cutout and a normal fuse link
• D. The ability to carry locked-rotor current of a motor but not to protect against short circuits

Answer: (C)

Dual-element fuses protect a motor circuit with two layers: a fuse link that provides fast short-circuit protection and a thermal cutout that guards against overheating from overloads or stalled conditions. The fuse link melts when current spikes—like during a short—to isolate the circuit quickly. The thermal cutout responds to rising temperature and trips if the motor overheats, often resetting after cooling. This combination means the device can handle both excessive current faults and overheating scenarios, which is why the correct statement describes both a thermal cutout and a normal fuse link. The idea of two normal fuse links misses the thermal protection, and a thermal cutout alone isn’t enough to protect against short circuits. Also, it’s not accurate to say it merely carries locked-rotor current without protecting against short circuits, since the fuse element provides short-circuit protection.