Unique-Bargains KSD301 120C 248F NC Thermal Switch 4PCS

KSD301 120°C Thermal Switch Pack

This set contains four KSD301 normally-closed thermal switches rated for 120°C (248°F) and 250 V AC at 10 A. They suit technicians and hobbyists who need over-temperature protection for heating elements in appliances such as irons, coffee makers or water heaters. The compact body measures 3.4 × 3.2 × 1.2 cm and uses two terminals for simple wiring. Buyers needing a different trip temperature or a normally-open contact will not be served by this model.

Bundled Quantity and Specifications

The pack delivers four identical units so one purchase covers multiple devices or spares. Each switch offers a circuit resistance of 50 MΩ, insulation resistance of 100 MΩ and withstands 1500 V AC for one minute. The contacts automatically reset when the surface cools roughly 5 °C below the trip point, restoring the circuit without manual intervention. No extra brackets, wires or mounting hardware are included in the box.

Installation Notes and Common Issues

The two-terminal design allows quick soldering or crimp connections, but the small 1.2 cm thickness leaves little room for bulky insulation. Ensure the sensing face makes firm thermal contact with the monitored surface; poor contact delays opening and can cause nuisance cycling. The mechanical life is rated at 10 000 cycles under rated load, so frequent over-temperature events will eventually wear the mechanism. Verify the 250 V 10 A rating matches the load before fitting.