KSD301 Normally Open NC Thermostatic Switch - 90°C Trip, Bakelite Housing, 250V 10A

A Normally Open (NO) configuration means the electrical contacts are open (no connection) when the switch is in its resting state at temperatures below its trip point. For the KSD301, the contacts close at temperatures below 90°C, allowing current to flow. When the sensed temperature reaches 90°C, the bimetallic disc snaps and opens the contacts, breaking the circuit to stop the connected load, such as a heater.

Yes, the KSD301 is rated for 250VAC and 10A, which exceeds common 120VAC household voltages. It can directly switch a 120VAC heater drawing up to 10 amps. Ensure the heater's steady-state current does not exceed the 10A rating. For inductive loads like motors, derating may be necessary to account for inrush current.

The switch typically has mounting holes for screws. Mount it securely with good thermal contact to the surface or component you wish to monitor (e.g., a metal heatsink or appliance housing). Wiring involves connecting the two blade terminals in series with the load (e.g., heater) and power source. Polarity does not matter for AC operation. Ensure all connections are tight and insulated.

The trip temperature for the KSD301 model is fixed at 90°C and is not user-adjustable. It is factory-calibrated using the bimetallic disc's mechanical properties. For a different trip point, you would need a different model number from the KSD series (e.g., KSD302 for 95°C).

This is an automatic reset thermostat. Once the switch trips open at 90°C, it will remain open until the temperature cools down below its reset temperature (typically several degrees below the trip point). The bimetallic disc then snaps back, closing the contacts to restore power to the circuit automatically.