Normally Closed (NC) Thermal Switch – 120°C

The device has a sensitive thermal element that reads the ambient temperature and, once the 120°C threshold is passed, trips the mechanism that opens the contact. Once the temperature drops back below the critical value, the contact closes again automatically and the circuit is restored.

The NC 120°C thermal switch is commonly used where electric motors, electronic equipment, battery power supplies and electrical installations need protecting from damage caused by high temperatures. It is particularly useful in devices that work in places with wide temperature swings, or that could overheat because of a fault.

• Controlling fans or cooling systems
  The switch opens the circuit when 120 °C is reached, automatically starting fans or cooling systems.
• Thermal warning (LED or buzzer)
  Used to trigger a visual or audible signal (e.g. an LED or buzzer) warning that the thermal threshold has been passed.
• Logic input for microcontrollers
  It can provide an input signal to a microcontroller when the temperature threshold is exceeded.
• Switching loads according to temperature
  Fitted in a circuit where a component is to be switched on only when the temperature rises above 120 °C (e.g. heating elements, relays, indicators, etc.).

• Sensor material:
  Bimetal: the sensor is made of two metals with different thermal expansion coefficients; when the trip temperature is reached, the bending of the bimetallic strip opens or closes the electrical contact.
• Reset: automatic (when the temperature drops below the threshold value)

• KSD9700 datasheet