KSD9700/BK05-BB1D Metallic Shell Temperature Control Switch - 75°C NC, 10A 250V

The KSD9700 series typically includes both automatic-reset and one-time (non-resettable) variants. This specific BK05-BB1D model is commonly an automatic-reset type. After tripping at 75°C, it will automatically re-close the circuit once the temperature cools below the reset point, which is usually several degrees lower than the trip point. Always verify the specific reset behavior for your application's safety requirements.

Wire the switch in series with the load (e.g., a heating element or motor) on the live (hot) wire of the power line you wish to protect. The two pre-attached leads are not polarized. When the ambient temperature around the switch's metallic shell reaches 75°C, the internal bimetallic disc will snap open, breaking the circuit and cutting power to the load until it cools down.

Standard bimetallic thermal switches like the KSD9700 typically have an actuation tolerance of ±3°C to ±5°C. Therefore, the actual trip temperature for this 75°C rated switch can range from approximately 70°C to 80°C. For critical applications, consider this tolerance and ensure the setpoint provides adequate safety margin for your protected components.

Yes, the rating of 250V and 10A applies to both AC and DC loads. The switching mechanism is mechanical, so it is suitable for DC circuits. Ensure the DC voltage does not exceed 250V and the current does not surpass 10A. Breaking a DC inductive load (like a motor) can be more demanding on the contacts than an AC load due to arcing.