Presuming there is not a circuit protective conductor running through the conduit to provide an earth connection to equipment and appliances connected to the circuit it is undoubtedly a C2.
If there is a circuit protective conductor running through the conduit I would still be inclined to go for a C2 as a insulation fault within the conduit, I know that’s unlikely but possible, would liven the conduit up without a fuse or MCB operating, it might take a RCD out but without a reasonable earth connection it’s not guaranteed.
So I would go C2 with or without a CPC conductor within the conduit.
Presuming there is not a circuit protective conductor running through the conduit to provide an earth connection to equipment and appliances connected to the circuit it is undoubtedly a C2.
If there is a circuit protective conductor running through the conduit I would still be inclined to go for a C2 as a insulation fault within the conduit, I know that’s unlikely but possible, would liven the conduit up without a fuse or MCB operating, it might take a RCD out but without a reasonable earth connection it’s not guaranteed.
So I would go C2 with or without a CPC conductor within the conduit.
