1. Application Background
Thermal protectors are crucial in the science and technology industry, particularly for systems like heating belts used in vacuum tubes and gas pipelines. When the heating system malfunctions and the temperature exceeds safe levels, these protectors activate to cut off the power supply, preventing further damage. The temperature switch is an integral part of this protection mechanism, ensuring the heating system operates within safe parameters.

2. Protection Principle
The temperature switch is a mechanical, passive component that plays a vital role in temperature regulation. It’s installed in the main circuit of the heating system. When the circuit malfunctions or the current surpasses the rated value, the temperature rises due to abnormal heating. The bimetallic heat-sensitive element within the temperature switch detects the change in temperature. Once the threshold temperature is exceeded, the bimetallic element deforms, disconnecting the circuit and cutting off the power supply, thus protecting the entire system.

Operation Flow:

• When the heat-sensitive element triggers, the contacts open, and resistance changes drastically, shutting off the main circuit.
• Once the temperature drops to the reset point, the element returns to its original state, and the contacts close, allowing the system to resume operation.

3. Installation Position
The temperature switch is ideally installed near the heating elements in the heating belt system, typically close to the heating wire. This ensures that the switch can detect temperature changes rapidly and provide timely protection.

4. Selection Factors

• Rated Current and Voltage: Ensure that the temperature switch is compatible with the heating belt's operating current and voltage for smooth operation.
• Protection Temperature: Select the temperature switch based on the required protection temperature. Common temperature settings are 120°C, 150°C, and 200°C.
• Contact Switch Form: Choose between normally open or normally closed switch forms, depending on the system design and needs. Normally closed contacts open at the protection temperature, while normally open contacts close.
• Size and Installation Mode: Ensure the size and installation mode of the thermal protector fit the heating belt’s specifications and installation space for easy installation and uninterrupted equipment operation.