Blown fuse element indicator

[drax]

Looking for help on an indicator that could be used to detect a blown copper link fuse that is rubber encased.  Does anyone know of a compound (plastic, etc.) that would change colors under intense heat?  Thanks in advance for any suggestions on a method of design for this.

 

[bfuchs]

Have you thought of paper ? ... just kidding...<br>I have heard of fuses that have a mechanical device that 'shoots out' when they blow. This form of trigger is used in the fuse switch to control an electrical switch (NO or NC). Is this what you are looking for ?

 

[drax]

This type of fuse is basically a copper bar (.50x2.5) with a machined down mid-section.&nbsp;&nbsp;The trouble is that there is really no way to tell if the thing is blown being that it is encased in rubber.&nbsp;&nbsp;I was thinking of an exposed section of plastic that could change colors due to the heat of interruption or maybe some sort of fragile ring surrounding the fuse element.&nbsp;&nbsp;Thanks for your response, any ideas would be greatly appreciated...<br><br>

 

[dclem]

Hey Drax,<br>&nbsp;&nbsp;&nbsp;&nbsp;There's a product on the market that electricians and thermographers use to indicate temperature of electrical conductors.&nbsp;&nbsp;It's like an identification label that is applied like tape . . . wrapped around the insulation of the conductor, and it changes color according to the temperature it has subjected to.&nbsp;&nbsp;I wish I could tell where to find it, but I don't know the manufacturer's name, (actually, I'm sure there are several manufacturers of this type of product).&nbsp;&nbsp;I would start looking at electrical wholesale houses.<br>Regards, DC

 

[Gibbs]

You didn't mention your application so neither of these may be useful.&nbsp;&nbsp;The old type plug fuses that screw into a fuse holder indicate they're blown (max rating is usually 30 amps or less).&nbsp;&nbsp;Bussman makes an R-rated fuse that has a small pin in the end which is pushed outward when the fuse blows.&nbsp;&nbsp;They are intended for motor protection and are only available in medium voltages, 2400 volts and above.

 

[PATAMAT]

Often a lamp is put in parallel with the fuse...so when the fuse is blown the lamp will light up. when the fuse is not blow it shorts the lamp and the lamp is not lit. [sig][/sig]