for instance, using 5x20 1A Fast Ceramic Fuse 250V in an installation ...

Not exactly what you asked for, but may help?

https://uk.rs-online.com/web/p/cartridge-fuses/1677869

Clive

BS EN 60127

You need to be careful about prospective fault current for these devices, it's relatively low … even HBC if memory serves is Max 1500 A

In my view, the limited breaking capacity of these small fuses means that they should not be used directly from the incoming supply, nor from a large sub main with a similar load capacity and potential fault current to a DNO supply.

They may, in my view be used  to protect small loads that are connected to a sub-circuit.

To connect a clock, small extract fan, emergency light, or the like to a 6 amp circuit, or any size circuit up to say 32 amps.

But not suitable for use in a consumer unit, or other equipment connected directly to the incoming DNO supply.

Also suitable for use within equipment that is connected to the supply via a relatively small OCPD.

If a one amp fuse is required for direct connection to the DNO, or other similarly large supply, then in my view a physically larger fuse with a larger breaking capacity should be selected. Such as a BS 88 type.

I might not even go as far as Broadgage.

In most installations, I would recommend BS EN 60127 fuses are restricted to appliances or equipment where an OCPD in the installation can be used as backup protection for the prospective fault current. 

Just a cautionary note that, where the supply is received at low voltage, the prospective fault current is not guaranteed to remain as low as you measured it on-site.

Thank you for the contributions

I had noticed too, that the braking capacity was relatively low. 

My thoughts were for their use in a [smaller form factor] fused terminal block requirement (I was discussing this a week or so back)   inside an enclosure, effectively to protect up close the final wiring to a lamp(s) arrangement.  It would indeed be backed up by a CPD at the board and really only offering overload protection.

I couldn't find the BSEN  in  7671,  but so long as all the factors required of it are satisfactory, I couldn't see an issue.

Is there anything to be aware of aside to what's already been mentioned in this thread please ?

Thank you

HAbS

I have seen this type of fuse used within fluorescent light fittings, but not that often. BS 1362 types were more common. 

A drawback of the mini fuses is the likelihood of replacement with unsuitable types. Plain glass fuses with a very low breaking capacity are available in this size. Sometimes as low as 100 amps, and that only at ELV, not suitable for mains use.

These type of disco light controllers had one or more 5 Amp or 6.3 Amp 20mm fuses inside them, one for each lighting channel. The unit was often plugged into a 13 Amp socket or  a 16 Amp socket. If supplied with glass 20mm fuses I would replace them with H.R.C. ceramic 20mm fuses of the correct rating.

Edit. Add. The history of N.J.D.

Z.

In days past such thing were used a lot inside TV sets and similar, and the glass bodied ones had a disappointing failure mode, where the end caps stayed in the holder, and the glass had to be swept out of the set with a dustpan and brush. Nowadays the glass bodied ones sometimes pop up inside things like laptop power supplied, and are one step up on the PCB weak link, but there is no expectation that they will be changed once blown, as the unit is sealed, and being sealed, the glass can be allowed to explode, and the unit remains safe. It does not sound nice but it is an acceptable design to allow the outer casing to catch the bits.

The other things to watch with really low values are failure on in-rush - they are a lot  friskier than say 13A plug style fuses, especially the ‘F’  (flink = fast,nimble) type let through is reassuringly low, and the significant element resistance, less of an issue on 230V..

Do not try to fuse your load too closely unless you use the ‘T’ (träge = slow, sluggish, lazy) type. Thanks DIN.

more generally 

DIN Marking	Description
FF	Very Fast Acting Fuse (Flink Flink)
F	Fast Acting Fuse (Flink)
M	Medium Acting Fuse (Mitteltrage)
T	Slow Acting Fuse  (Trage)
TT	Very Slow Acting Fuse  (Trage Trage)
	Slow Acting Fuse