i have added a shower circuit to my home. i have an old mem fuse board and cant add to it as they dont make those rewireable fuses anymore. i have bought a \\\"shower pack\\\" which includes a 63 amp rcd and a 40 amp mcb. how do i connect into what is there? there is no isolator at the cut out, only at the fuse board which obviously doesnt deadon ( is that a word?!! ) the incoming. do i need to use a tails splitter? if so how do i isolate the incoming? pull the main fuse? i have never done this and have been told its illegal. but also been told that the leccy board can make you go without power for days if they pull the main! or do i do it live?? any help will be appreciated