Generic KSD301 Ceramic Temperature Controlled Switch Thermostat - Normally Closed NC, 100°C, 250V 16A

The KSD301 is a Normally Closed (NC) switch. Its contacts are closed at temperatures below its 100°C setpoint. When the sensed temperature reaches 100°C, the internal bimetallic disc snaps and opens the contacts, breaking the circuit. It does not automatically reset; the contacts close again only after the device cools down below the reset temperature.

This thermal switch is rated for a maximum of 250 Volts AC or DC and a current of 16 Amps. This rating is typically for resistive loads. For inductive loads (like motors or solenoids), derating or additional protection (like an RC snubber) may be required to handle voltage spikes and extend contact life.

Install the switch in direct thermal contact with the component or surface you wish to monitor (e.g., a heat sink or motor housing). Secure it using its mounting bracket or adhesive. Wire it in series with the load you want to control or protect. The two terminals are not polarized; connect one side to the power source and the other to the load for SPST-NC operation.

The actuation temperature is fixed at 100°C and is not user-adjustable. It is factory-calibrated using the specific bimetallic disc. The typical operating tolerance is ±5°C. For a different setpoint, you would need to select a different model from the KSD series (e.g., KSD302 for 120°C).