I manage a residential mobile home park with homes that individually have mains supply TT coming to a meter box recessed into a breeze block shed. The tails then come from the meter into the shed and into an old style bakelite rewireable 40a fused isolator switch. There is then an outgoing 10mm SWA cable running from the isolator switch underground from the shed to the home and then into the consumer unit for the home (total run approx. 8 to 10 metres). Having had an EICR for one of the homes I have been adviced that these isolator switches will need to be replaced as the swa cable is not properly terminated (it is not glanded in to the isolator switch and the wire stranded sheathing is twisted together and connected to the earth block.) My question is can this isolator switch be replaced with an 18th edition 3 way metal enclosure with double pole isolator switch and 40a mcb or should it be replaced with a 60a (or 40a) cartridge fused double poled mains isolator switch. Additionally would it a be a good idea to put a 60a RCD into the shed and either use a five way enclosure (in place of 3 way enclosure) or a 2 way enclosure fed from the cartridge isolator switch. All the homes have a standard consumer unit containing either a 60a or 80a RCD and 3 to 5 suitable MCB's (32a, 16a, 6a).