KSD9700/BK05-BB1D Metallic Shell Temperature Control Switch 130C NC - 10A 250V

This specific KSD9700/BK05-BB1D model is a Normally Closed (NC) switch. This means the electrical circuit is complete (contacts are closed) under normal operating temperatures below 130°C. When the sensed temperature reaches the 130°C trip point, the internal bimetallic disc snaps and opens the contacts, breaking the circuit to stop current flow and provide protection.

The switch is rated for a maximum of 250 Volts AC or DC and a maximum current of 10 Amperes. It is crucial not to exceed these ratings to ensure safe operation and prevent contact welding or switch failure. The 10A rating applies at the full 250V, making it suitable for protecting significant loads like heating elements or motor windings.

Installation requires mechanically securing the metallic shell (typically via a bracket or clip) directly to the component or surface whose temperature you need to monitor, ensuring good thermal contact. Electrically, you connect the two pre-attached 7cm lead wires in series with the load (e.g., the heater or motor) and the power source. The switch acts as a thermal fuse, interrupting power to the load when its set temperature is exceeded.

The reset behavior depends on the specific variant of the KSD9700 series. Some models are automatic reset, where the contacts close again once the temperature cools below the trip point. Others are manual reset or single-use. The product title specifies 'Normally Closed' but not the reset type. For critical safety applications, verify the exact reset specification with the supplier or assume a manual-reset design for fail-safe operation.