The KSD 9700 temperature switch is available in two main contact configurations:
1. Normally Closed (NC) Type
Default state (below rated temperature): The contacts are closed, circuit is ON → current flows.
When temperature rises to the set point: The bimetal disc bends, the contacts open, and the circuit is cut off.
When temperature drops back down: The contacts close again automatically, restoring the circuit.
Typical applications:
Over-temperature protection (motors, transformers, batteries).
Appliances or tools where the power must be cut off if overheating occurs.
Think of it as a safety fuse with auto reset - power is allowed normally, but cut when overheated.
2. Normally Open (NO) Type
Default state (below rated temperature): The contacts are open, circuit is OFF → no current flows.
When temperature rises to the set point: The bimetal disc bends, the contacts close, and the circuit turns ON.
When temperature drops back down: The contacts open again automatically, turning the circuit OFF.
Typical applications:
Temperature-triggered control (e.g., turn on a cooling fan, alarm, or heater when a threshold is reached).
Systems where an action is required only once a certain temperature is exceeded.
Think of it as a temperature switch - normally OFF, but switches ON when hot.
3. Key Specifications
Voltage / Current ratings:
Common: 250V AC, 5A (also available in 125V, 3A versions).
Temperature range:
Usually 40°C to 150°C, customizable (e.g., 60, 70, 80, 90, 100, 105, 110, 120°C etc.).
Reset type:
Mostly auto-reset (contacts return when cooled).
Some models can be manual reset.
Housing materials:
Metal case → faster response, better heat conduction (but needs insulation).
Plastic case → safer insulation, but slower response.
