Check your fuses!

[Buck Turgidson]

It was a blade fuse as fitted by OEM so I don’t know the brand. The plastic cap of the fuse was completely melted and had fused the holder closed. More pics when I get home.

Here you can see the melted blade fuse plastic inside the cap.

 

[Cerebus]

You’re right Paul, in my experience when a fuse is never cleaned, corrosion builds up on the connections causing high resistance and heat. The old plastic “Continental” fuses where a bugger for this as the plastic body would melt.

Posts numbers six and seven suggest the fuse heated and post seven gives a possible reason.

I found this news shocking (no pun intended) and would like to know if anyone can confirm post seven is the answer or could there be other causes?

It really looks like a nasty incident that all sailors would like to avoid.

 

[Seamonk]

Ancor makes these beauties:
Blue Sea Blade Fuse Block

 

[Bouba]

Ancor makes these beauties:
Blue Sea Blade Fuse Block

They look exactly like the ones on my electric cupboard.....problem is there are extra fuses around the boat on various equipment....some of which I don’t actually know

 

[Dockhead]

If a fuse doesn’t blow...but melts the housing...suggest to me that it needs replacing by a lower amp fuse

Or a higher amp fuse.

Fuses by design get hot when they are used at near their rated capacity. A fuse which is too small may heat up inordinately even when there is no fault in the circuit.

The fuse should be rated to protect the wiring and junctions, and the whole lot of them should have plenty of reserve capacity compared to the load. If the fuse is sized correctly for the circuit but the load is near the capacity of the circuit, then inordinate heating of the fuse would be a natural consequence. Good practice would call for the whole circuit to be upgraded. Don't, for example, run an 18A load on a 20A circuit with a 20A fuse.


ChatGPT. Note that this assumes the fuse is in open air. If it's enclosed like in the OP, it will get even much hotter.

 

[PCUK]

My post was from experience.

 

[penberth3]

My post was from experience.
View attachment 193677

Interesting. More Chinese crap? Those fuses were always ceramic, not plastics, so couldn't possibly melt.

 

[Cerebus]

Yes one would expect the white material to withstand heat better than the thickest part of the metal.

Crazy.

 

[DangerousPirate]

What? It still worked? Now that is a real concern!

 

[PaulRainbow]

What? It still worked? Now that is a real concern!

It will still work, the fuse didn't blow, it got hot and melted the holder.