I have been testing a 1 Amp resettable fuse on a 12 Volt supply. The supply cuts off instantly when I put a dead short on the output. However I am worried that the resettable fuse gets VERY hot. How long will it last with a dead short?

 

Hello,

What kind of resetable fuse are you using ?
The polyfuse are working on heating by overcurrent .
The heating will raise the resistance of the polyfuse .
There are also mechanical resetable fuses .

Bertus

 

I found a shorted car door lock switch that had been under safety lock out with a polyfuse for months, and it was still working when I found the fault. So, there you are. These things can safely hold in overload condition for months.

 

Hello,

What kind of resetable fuse are you using ?
The polyfuse are working on heating by overcurrent .
The heating will raise the resistance of the polyfuse .
There are also mechanical resetable fuses .

Bertus

Its a poly fuse

I have attached the datasheet from the supplier

 

Hello,

Here is a page from littlefuse about the polyfuse versus a conventional fuse:
http://www.littelfuse.com/technical-resources/education-center/fuses-vs-ptcs.aspx

A polyfuse will "reset" as soon as the overload is removed.
The removal of the overload will let the polyfuse cool down and have a low resistance again.

Bertus

 

The polyfuse will reach an equilibrium temperature and resistance where just the right amount of current conducts in order to maintain a given temperature.