mapj1:

531.3.5.3.2.201

For Class I enclosures in TT systems where RCD protection is used on outgoing circuits, double or reinforced insulation of all live conductors (incoming cables, extension terminals, etc.) on the supply side of the incoming device, e.g. main switch, shall be used. Insulated and non-metallic sheathed cables are deemed to meet the requirements of double or reinforced insulation.

NOTE: Consideration should be given to the manufacturer's internal live interconnecting cable links on the supply side of an RCD being double insulated, having reinforced insulation or equivalent mechanical protection.

To me the 'NOTE' is not strong enough. You may consider it if you like but it rather leaves the door open to misinterpretation . To have insulated and sheathed meter tails into to a DIN rail main switch, but then some bare bus bar to take live feed from the switch to a row of RCBOs, or in the CU of at least one well known brand what looks like very thick enameled wire to the RCDs  appears to be acceptable,  so in one case nothing and in the other only varnish insulating a pre RCD live, and I rather think it should not be.


I'd be far happier if it said "double or reinforced insulation  is required for all wiring not protected by an RCD or RCBO"

It does not.

mapj1:

531.3.5.3.2.201

For Class I enclosures in TT systems where RCD protection is used on outgoing circuits, double or reinforced insulation of all live conductors (incoming cables, extension terminals, etc.) on the supply side of the incoming device, e.g. main switch, shall be used. Insulated and non-metallic sheathed cables are deemed to meet the requirements of double or reinforced insulation.

NOTE: Consideration should be given to the manufacturer's internal live interconnecting cable links on the supply side of an RCD being double insulated, having reinforced insulation or equivalent mechanical protection.

To me the 'NOTE' is not strong enough. You may consider it if you like but it rather leaves the door open to misinterpretation . To have insulated and sheathed meter tails into to a DIN rail main switch, but then some bare bus bar to take live feed from the switch to a row of RCBOs, or in the CU of at least one well known brand what looks like very thick enameled wire to the RCDs  appears to be acceptable,  so in one case nothing and in the other only varnish insulating a pre RCD live, and I rather think it should not be.


I'd be far happier if it said "double or reinforced insulation  is required for all wiring not protected by an RCD or RCBO"

It does not.