Beware eBay fuses/ fuse holders

[DonnieBrodan]

I blew up an ESP32 Devboard connected to a 12v PSU recently, just got a new ESP32 in the mail, went to test it and no power. Went to check the inline fuse that I installed... Well isn't this interesting...




You can see the case for the fuse is all warped. Might think that a fuse labelled F1AL250V would blow before warping the plastic? Unsure if the fuse did actually blow, as when I went to pull the fuse out, it shattered into many pieces.

Edit: should have been a 200mA fuse, thats likely what caused this

[mikerj]

I suspect the problem is you don't have enough cable splices, I can see runs of almost an inch of plain wire without a splice 

The fuse holder almost certainly melted due to a bad contact to the end of the fuse causing the heating.  Most of of these junky connectors and fuse holders use inappropriate metal and/or plated finishes that oxidise and cause poor connections.

[CJay]

I suspect the problem is you don't have enough cable splices, I can see runs of almost an inch of plain wire without a splice 

 

You can get a surprising amount of heat out of a fuse being run at or close to its rating, used to amuse me when I was repairing audio power amps to watch them on full output test into a load bank because some of them had fuses which would glow orange and sag in time with bass beats.