KSD301 Ceramic Temperature Control Switch Thermostat - 105°C NC, 250V 16A

The KSD301 is a non-resetting, one-shot thermal switch. Once the internal bimetallic disc actuates at 105°C and opens the contacts, it does not automatically reset when cooled. It must be manually replaced or, in some designs, a separate reset button may be pressed if the model variant includes it. It is primarily designed as a safety cutoff.

While rated for 250V AC / 16A, it can typically handle DC voltages at a significantly derated current due to arc suppression. For DC applications, consult derating curves. It is perfectly safe for lower current applications; the rating indicates its maximum capacity, not a minimum requirement.

Install the switch with its metal sensing face in direct thermal contact with the component or surface to be monitored (e.g., heater sheath, motor housing). Wire the two terminals in series with the load (e.g., heating element) on the live (hot) side of the AC line. Ensure wiring is secure and insulated, respecting the 250V/16A rating.

Standard bimetallic thermal switches like the KSD301 typically have an actuation tolerance of ±5°C to ±10°C. The exact tolerance is not usually specified on Generic components. For critical applications, batch testing or selecting a switch from a supplier providing a calibrated tolerance band is recommended.