I have on "old" style fusebox with 1 white,1 blue and two red fuses. I have established that the ring main circuit upstairs &n downstairs is connected to one of the red fuses. The other red fuse is used for the 45amp cooker control unit.Is it just a simple matter of upgrading the fusewire in this "red" fuse to 45amp fuse wire , I assume that the existing fuse as 30 amp fusewire.