in the event of an earth fault, what will operate and disconnect the supply?

Question

in the event of an earth fault, what will operate and disconnect the supply of an installation with an earhted equipotential bonding and automatic disconnection where the circuit is not protected by an rcd?

Answer 1

If it is low voltage circuit, it will be isolated by the fuse if not tripped by the miniature circuit breakdr (mcb) or mccb.
If it is higher voltage (that is in kilovolts,) it will be isolated by the local circuit breaker, and if it fails, then the circuit breaker which feeds the local circuit.