Also known as thermal cut-offs, these fuses prevent equipment from overheating by opening circuits to cut off power. They react to excessive temperature in the same way electrical fuses react to excessive current. They can’t be reset, so replace them once they open.

Choose a fuse based on your device's normal operating temperature and the temperature at which you want the fuse to trip. Opening temperature is the temperature at which the fuse trips and turns off the device. Maximum operating temperature is the highest temperature a fuse can handle on an ongoing basis. These fuses tolerate temperature spikes that fall between the two values, but prolonged exposure to temperatures above the maximum operating temperature may cause the fuse to fail.

Parallel lead fuses take up less space on a crowded circuit board than inline lead fuses. Solder to connect.