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Ivan Vegvary
Nov 9, 2015, 11:40:57 AM11/9/15
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Replacing thermal fuse in wall oven power supply.
Does fuse measure temperature of ambient, or, temperature based on current through fuse?
I ask because I would like to attach wire leads to fuse since I screwed up soldering directly to the board.
Thank you.
Does fuse measure temperature of ambient, or, temperature based on current through fuse?
I ask because I would like to attach wire leads to fuse since I screwed up soldering directly to the board.
Thank you.
Cydrome Leader
Nov 9, 2015, 12:40:18 PM11/9/15
to
Ivan Vegvary <ivanv...@gmail.com> wrote:
> Replacing thermal fuse in wall oven power supply.
> Does fuse measure temperature of ambient, or, temperature based on current through fuse?
It just measures heat, doesn't matter where it comes from. But-
> Replacing thermal fuse in wall oven power supply.
> Does fuse measure temperature of ambient, or, temperature based on current through fuse?
Keep in mind heating the fuse with current will heat the inside to a
higher temp that just warming the outside as there is thermal resistance
of the device package to overcome.
Just be careful soldering the leads and you should be ok.
John Robertson
Nov 9, 2015, 1:36:40 PM11/9/15
to
their design failure point.
Certainly if you pass too much current through it will fail! Most
thermal fuses are on heat sinks or fans and open at relatively low
temperatures to indicate that the fan or cooling system has failed and
this helps to protect the electronics from heat failure.
Due to their sensitivity they are hard to solder without opening
internally! You MUST heatsink the leads to protect the element inside
the thermal fuse from getting too hot. A heatsink can be the jaws of
needle nosed pliers or similar clamp with lots of metal to absorb the
heat of soldering. I'm not certain that all types of thermal fuses can
even be soldered - most I've seen have metal clips clamping them to the
wires. You may have to experiment. You probably should get more than one
in case of failure...
Pigtail screw-on clips might work fine.
John :-#)#
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N_Cook
Nov 9, 2015, 5:14:37 PM11/9/15
to
On 09/11/2015 18:36, John Robertson wrote:
> On 11/09/2015 8:40 AM, Ivan Vegvary wrote:
>> Replacing thermal fuse in wall oven power supply.
>> Does fuse measure temperature of ambient, or, temperature based on
>> current through fuse?
>> I ask because I would like to attach wire leads to fuse since I
>> screwed up soldering directly to the board.
>> Thank you.
>>
>
> Thermal fuses are supposed to open when their temperature rises above
> their design failure point.
>
> Certainly if you pass too much current through it will fail! Most
> thermal fuses are on heat sinks or fans and open at relatively low
> temperatures to indicate that the fan or cooling system has failed and
> this helps to protect the electronics from heat failure.
>
> Due to their sensitivity they are hard to solder without opening
> internally! You MUST heatsink the leads to protect the element inside
> the thermal fuse from getting too hot. A heatsink can be the jaws of
> needle nosed pliers or similar clamp with lots of metal to absorb the
> heat of soldering. I'm not certain that all types of thermal fuses can
> even be soldered - most I've seen have metal clips clamping them to the
> wires. You may have to experiment. You probably should get more than one
> in case of failure...
>
> Pigtail screw-on clips might work fine.
>
> John :-#)#
>
Another tip is to freezer spray the body of the thermal fuse before
> On 11/09/2015 8:40 AM, Ivan Vegvary wrote:
>> Replacing thermal fuse in wall oven power supply.
>> Does fuse measure temperature of ambient, or, temperature based on
>> current through fuse?
>> I ask because I would like to attach wire leads to fuse since I
>> screwed up soldering directly to the board.
>> Thank you.
>>
>
> Thermal fuses are supposed to open when their temperature rises above
> their design failure point.
>
> Certainly if you pass too much current through it will fail! Most
> thermal fuses are on heat sinks or fans and open at relatively low
> temperatures to indicate that the fan or cooling system has failed and
> this helps to protect the electronics from heat failure.
>
> Due to their sensitivity they are hard to solder without opening
> internally! You MUST heatsink the leads to protect the element inside
> the thermal fuse from getting too hot. A heatsink can be the jaws of
> needle nosed pliers or similar clamp with lots of metal to absorb the
> heat of soldering. I'm not certain that all types of thermal fuses can
> even be soldered - most I've seen have metal clips clamping them to the
> wires. You may have to experiment. You probably should get more than one
> in case of failure...
>
> Pigtail screw-on clips might work fine.
>
> John :-#)#
>
pre-tinning the wires and then repeat freezing before soldering proper.
Phil Allison
Nov 9, 2015, 9:17:34 PM11/9/15
to
Ivan Vegvary wrote:
>
>
> Replacing thermal fuse in wall oven power supply.
> Does fuse measure temperature of ambient, or, temperature
> based on current through fuse?
** Thermal fuses respond to the temperature of the case and are designed to have low self heating due to current flow. Makers specify the operating temp and also give a max continuous current rating at which self heating is not significant.
>
>
> Replacing thermal fuse in wall oven power supply.
> Does fuse measure temperature of ambient, or, temperature
> based on current through fuse?
> I ask because I would like to attach wire leads to fuse since
> I screwed up soldering directly to the board.
>
.... Phil
Ivan Vegvary
Nov 10, 2015, 8:30:04 AM11/10/15
to
Thanks everyone! Decided to crimp on some 2" leads and thereby keep soldering heat far away from the Thermal Fuse.
Your help is greatly appreciated.
Your help is greatly appreciated.
Fred McKenzie
Nov 11, 2015, 1:27:40 PM11/11/15
to
In article <9d349513-df7d-4592...@googlegroups.com>,
Ivan-
When I've soldered a thermal fuse, I held a lead by a heavy pair of
pliers next to the body. The pliers had a rubber band around the
handles so my hands were free. So far there were no failures due to
soldering.
Some thermal fuses are supplied with a little brass sleeve for crimping.
However, it is difficult to get a good crimp between two solid wires.
Be sure you crimp to a stranded wire with the solid wire in the same
bundle.
Fred
When I've soldered a thermal fuse, I held a lead by a heavy pair of
pliers next to the body. The pliers had a rubber band around the
handles so my hands were free. So far there were no failures due to
soldering.
Some thermal fuses are supplied with a little brass sleeve for crimping.
However, it is difficult to get a good crimp between two solid wires.
Be sure you crimp to a stranded wire with the solid wire in the same
bundle.
Fred
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