GB/T 9816.2-2018 in English

GB/T 9816.2-2018, as the second part of the thermal cutoff series standard, specifically regulates the special requirements of organic temperature-sensitive thermal cutoff. This standard is applicable to protective devices for preventing overheating in indoor electrical and electronic equipment, and the technical indicators cover three dimensions: mechanical strength, electrical performance, and temperature characteristics.

1. Mechanical test

Bending/twisting test:As shown in Figure 1, bend 90° at a distance of 10mm from the body and then perform 180° forward and reverse twisting. After the test, the electrical strength verification must be passed.

2. Electrical test

Load aging test:Apply rated current Ir, heat up to Th-3K~Th range at a rate of 0.5-1K/min, keep for 1.5 hours and then cool down. After 200 cycles, verify the stability of the operating temperature.

3. Temperature test

Graded temperature rise test:For products ≤250℃, start from Tf-12K, and for products >250℃, start from Tf-22K. Record the operating point at a rate of 0.5-1K/min. The measured value is required to be within the declared tolerance range.

Selection considerations

• For vibration environments, it is recommended to use encapsulated thermal fuses and pass the 50Hz/3g vibration test
• High-temperature applications (such as electric irons) require special verification of material heat resistance (GWIT≥850℃)
• Lead cross-sectional area and current carrying capacity match (see standard Table 3)

Installation specifications

According to Appendix A, the distance between the welding point and the body should be ≥3mm, and the mounting bracket must be able to withstand 98N mechanical stress. For safety-critical equipment, it is recommended to use a dual thermal fuse redundant design.