On 03/14/2016 9:56 AM, Jeff Wisnia wrote:
Over the years I've had to replace maybe a half dozen thermal fuses
which appear to have failed without ever being heated beyond their rated
temperatures.

Most recently a small electric space heater used in our office under my
desk stopped working because its thermal fuse had opened. The fuse was a
MICROTEMP G4A0 121 degree C unit, and I'm pretty sure that nothing had
blocked air passage through the heater and caused its internal
temperature to rise enough to open the thermal fuss.

Jeff



My expectation is yes, they do fail from age/power cycles. Most likely
failure point is the wire to passive element junction...why not take it
apart and see?

John :-#)#

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