Thermal Fuse - Holding Temperature vs. Rated Functioning Temperature

The Holding Temperature is the Max Temperature that the Thermal Fuse will continuously operate at without opening.
Keep in mind if the Temperature is exceeded for a period of time the thermal fuse can open.
The Rated Functioning Temperature is the Minimum Temperature that the Thermal Fuse is rated to open.
However, Thermal Fuses can open between the stated holding and the functioning temperature ratings.

Thanks. But the old thermal fuse that I want to replace has printed on it a temperature of 174 deg. C. Is that he holding or functioning temperature?

Hi jcmetzler777,

Welcome to the Tech Forum!

Well, I can’t say whether every manufacturer follows the same standard or not, but it looks like most, if not all of the types we sell print the functioning temperature on the thermal fuse.


A 98°C thermal fuse: