micky wrote:

On Thu, 22 Mar 2012 00:03:41 -0400, jeff_wisnia
wrote:


Over the years I've had a few thermal fuses in houshold appliances go
open for no apparent reason. When I've replaced them with ones with the
same temperature rating they stayed working fine for years more.

A couple of days ago our three year old Bunn coffee maker quit, because
a 141 degree celcius overtemperature thermal fuse on the water tank
opened. It might possibly have happened because the water tank
thermostat stuck closed, but after I repaired it the thermostat cycled
just as it should.

I was suprised to find that there were TWO identical thermal fuses
connected in series located right next to each other, the bodies were
actually touching. That seemed like a belt and suspenders approach,
unless there's a significant likelihood that a thermal fuse won't open
when it should?


I wouldn't think they fail just from age, but what do I know?

I r eally posted to ask how you crimp them in place, what kind of
connector do you use?

And where do you buy them?


Comments?


May it be our biggest problem.

Thanks guys,

Jeff



The one I replaced is about the size of a 1/2 watt carbon resistor and
looks like this:

http://parts.digikey.com/1/parts/726...df-df141s.html

The way the original was installed The fuse's leads were left about an
inch long and the flexible insulated wires connecting to them were
fastened with little uninsulated metal crimps. I didn't have any of
those crimps so I just clamped a heat sink to the fuse's lead wire and
quickly soldered the flexible wire to the fuse lead with an 1/8 inch
long lap joint.

(Probably more than you needed to know, eh?)

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.