dummy question about fuses

[boatmike]

I should really know the answer to this but a friend has sown doubt in my mind. If I have a fuse on my boat that says 10 amp is that same fuse still good for a 240 volt application? I have a 240 volt electric gate operating system and the fuse has blown. Its a simple round ceramic bodied fuse like a household 13 amp one that you commonly find in 3 pin plugs but smaller and marked 10 amp.. looks identical to spare line fuses i have on my boat but that's a 12v system of course. Are they the same? The fuse on my gate is mounted on a PC board and although the system is fed by 240 volt household supply I don't of course know the precise voltage across the fuse but does it actually matter?

 

[Dellquay13]

If it is a 20mm fuse, look carefully at the metal ends, it should give a voltage rating as well as the amperage and possibly F or T for fast blow or time delay.
I personally haven’t seen a 20mm fuse not rated at 250v, and in many cases I have seen these 250v fuses in circuits around 12-50v, so your boat ones may be 250v rated.
Someone will now prove me wrong though…

This picture shows the dimensions, but the voltage rating is usually stamped into the metal ends, not on the ceramic body as here. The glass variant is also used.

 

[B27]

Some low voltage fuses are only rated to 30 or 40 V, above that they may just arc over.
You can certainly get 20mm mains fuses in fast blow, slow blow and all sorts of ratings, most seem to be 250V rated.
For a motor you probably want a slow-blow fuse, or at least not a quick blow.

 

[andsarkit]

Glass 20mm fuses only have an interrupt capacity of 32A to 80A depending on the fuse rating. Ceramic 20mm fuses are often 1500A interrupt capacity but there are exceptions to this. In practice either fuse will just blow if overloaded and you will also have other circuit protection in the main distribution box feeding the gate circuit. If you are buying new fuses you might as well get the ceramic ones as the extra cost is minimal.
Do you know why the fuse has blown? It could be old age or has the mechanical mechanism seized and overloaded the motor. It might be worth checking for free movement with an oil can in your spare hand.