mattyj wrote:That's an interesting regulation.
Out of interest which edition of BS7671 are you referring to?
The Green Regs. 16th Edition Second Edition (voltage and colour harmonisation)
mattyj wrote:The problem with that old regulation is that a user can replace the fuse / cartridge with a higher value.
Not if the installation has a proper fuseboard where it's impossible to insert a lower rated fuse holder. As opposed to the modern cheap-tack MCB/RCD things
mattyj wrote:I may have a chat with an NICEIC inspector to find out the history behind it's omission from the current regulations.
It makes a lot of installations non-compliant if they were new, particularly 16mm supply tails which I find in practially every house built before about 1980.