If anyone could help me that would be great. Wired a sub-main for an extension from an existing MK split load board in 16mm t+e. MK don't seem to make a 63a MCB for it 50 is the highest. Does anyone know which brand MCB (if there is one) suitable or will just fit in the CU? Wholesaler's weren't particularly helpful , I know the BG fit's but maximum they come in is a 50a.