External fuse sockets. Mounting advice and safety rules question

[catalin gramada]

Supposed all types of fuses socket devices are agreed to be used from a standard safety perspective according to the law, I wonder if exist also some safety rules to follow when mount it ? I just imagine possible scenario when opening the cap the fuse remains stucked into the socket with a live end exposed, very possible. There are any safety rules for mounting external fuse sockets please ? Thx.

[vintagekiki]

Any intervention regarding the replacement of fuses implies that the device is previously disconnected from the voltage by disconnecting it from the wall.

[catalin gramada]

Sure it is but this didn't excuse the potential danger. Think more 100% safe. I remember in the past some external fuse sockets which can be opened just with a scew drivw but many can be opened by a child from curiosity.

[g1]

The convention is that the live wire should attach to the rear post of the fuse holder (the terminal furthest from fuse-cap).
I'm not sure if there are actual standards that dictate this.

[vintagekiki]

If 100% safety is meant, the only solution is fuses inside the device.
External fuse sockets are made of more or less brittle materials (bakelite) where the moving part is subject to damage.
Specific tools like scew drive may be the solution, but they are not practical because sockets are not standardized, so every guitarist must have a gallery of tools to replace the fuse.

[Dave H]

I just imagine possible scenario when opening the cap the fuse remains stucked into the socket with a live end exposed

I think "touchproof fuseholders" were designed to prevent this.

[vintagekiki]

The convention is that the live wire should attach to the rear post of the fuse holder (the terminal furthest from fuse-cap).
I'm not sure if there are actual standards that dictate this.

This solution is not possible at EU devices, because the mains socket is symmetrical, unlike western devices where the mains socket is asymmetric.
In addition, when a faulty fuse is replaced with a correct, the voltage from the rear post of the fuse holder via correct fuse comes to the front fuse holder.

[Enzo]

Old style fuse holders allowed one to still touch the fuse with the cap off. But newer ones have the fuse recessed so this cannot happen.

[loudthud]

There are IEC socket and fuse combo units that force you to detach the Mains cable before you can access the fuse.

[vintagekiki]

[J M Fahey]

Even "touchproof" fuse holders and recessed (but still visible fuse) ones *can* fail and retain fuse and other end is live, so the one you touch too.

Only really safe one is the one included together with male IEC sockets, I use the stand alone version, which holds the fuse in a small plastic drawer or cradle, contacts are internal.

So fuse is either inside and surrounded by plastic or outside and **BOTH** contacts are outside, connected to nothing.

Similar to this cradle:



I couldnīt find images (wrong search term?) but I use the stand alone type, similar to tye lower section of this picture.