I guess the main issue is verifying that the fuse is <=100A. Without knowing that the cutout is of a type which only accommodates <=100A fuses, you're into speculation territory . . .
No speculation required. Where “whole current” metering is used, that is the current carrying conductors route directly through the tariff meter, the cutout fuse will always be 100A or less. Where a “looped service” is observed, such as the photo in this thread, it is probable that the cutout fuse will be either 60A or 63A.
Actually, it is a lot neater than one I saw recently where there is a horrific confustication of Henley blocks and short lengths of tail to achieve a similar effect, but in open air, with 21 flats and a 'landlord' meter split out across 3 phases, each with a 60A switch fuse as well. In that case though the incomer was 3 phase 100A, so some quite fierce diversity assumed, or more likely it just grew like topsy and has never been designed formally.
well, at least they look like someone has thought about it, and left enough room to do a decent job, with post meter switch fuses and so on. Not so keen on the mid row of trunking with both pre-meter and post meter cables being mixed inside - is it tamper sealed ?
