KSD9700/BK05-BB1D Metallic Shell Temperature Control Switch - 130°C Normally Open, 5A 250V

The KSD9700/BK05-BB1D is factory-calibrated to open its normally open (NO) contacts at 130°C. Typical bimetallic switches of this type have an operating tolerance of approximately ±5°C around the set point. The exact trip point is fixed and not user-adjustable.

This thermal switch is rated for a continuous current of 5 Amps at a maximum voltage of 250 Volts, either AC or DC. It is designed for resistive loads typical in heating elements and motor protection. For inductive loads, derating may be necessary to ensure contact longevity.

Wire the switch in series with the load (e.g., a heating element) on the live or hot wire. In its normal state below 130°C, the circuit is open and no current flows. When the ambient temperature around its metallic shell reaches 130°C, the internal bimetallic disc snaps, closing the circuit to break the connection and cut power to the load for protection.

Yes, this is an automatic, resettable snap-action switch. Once the temperature cools below the trip point (typically by 10-20°C), the bimetallic disc resets and the contacts return to their normally open state, restoring the circuit. The robust housing is a metallic shell, providing good thermal conduction for accurate sensing and mechanical durability.