No earth in cable?

[ericmark]

such a circuit should already be fused at 6A.

There is no requirement for a lighting circuit to be protected with a 5/6A device.

It depends on what is in the circuit. A B22d bulb holder is often rated 2A but in theory there should be a built in fuse in the bulb so that does not reflect on supply fuse size. But a ceiling rose is used as a junction box and only they are only rated either 5 or 6 amp so they will limit the size of the supply MCB/fuse/RCBO even using some 5A connector strip.

So although if suitable components are used you could protect up to 16A in the main suitable components are not used so yes should be fused at 6A.

 

[Risteard]

A B22d bulb holder is often rated 2A but in theory there should be a built in fuse in the bulb so that does not reflect on supply fuse size.

Why? The lampholder will only pull a maximum of the connected load through it, so as long as short circuit protection is afforded what need is there for additional fusing?

 

[Risteard]

How do you know what the internals of the appliance will withstand?

I know what a BS 1362 fuse is intended for, and that isn't it.

Do you think that a manufacturer cannot design his product to withstand the let-through energy of a BS1362 fuse?

If a manufacturer wanted closer protection then they certainly wouldn't be achieving this through the use of a BS 1362 fuse. To suggest that they would or could is frankly ludicrous.

A 3A BS 1362 fuse won't offer any benefit over a 6A BS EN 60898 circuit breaker - there isn't even any guarantee with a 32A BS EN 60898 circuit breaker!