Debate at work...what code would you give a earth leakage switch as main isolator in domestic property
I can only assume the op is talking about a front end rcd? The c/unit would have a main switch, if this is the case I don't see any code necessary.
Its not exactly a lot of info on which to make a decision. If your talking about a 30ma RCD covering the whole board then only a C3 as a recommended improvement. you still find in older TT installations there may be a 100mA RCD as a main switch covering the lights ect, then a 30ma for the sockets even then just a C3 as long as they still trip.
If youre talking about an old voltage operated elcb,and its the sole protection on a TT supply,then it needs rectifying with haste. C2
If it’s a 30mA RCD then C3. It breaks the reg regarding splitting of circuits- single point of failure. But then a dual RCD CU has that feature as well!!