Terminal blocks - no fusing down?

What I wonder is then how such distribution blocks like these Weidmüller AWPD 35 4X6/6X2.5 are safe:

Such blocks are often used as Neutral commoning blocks - in such cases the smaller conductors will be protected by the OPDs on the corresponding L conductors (ignoring faults between conductors of differing circuits, which is usually the case).

Where they're used on Line conductors, there will usually be downstream overcurrent protection which will protect the smaller conductors from overload and fault protection is either provided by an upstream device (in general an OPD will provide fault protection to much smaller conductors than it could provide overload protection for), or fault protection is omitted (most standards have provision for that - e.g. where the connections are short, precaution are taken to minimise the chances of a fault occurring, and precautions are taken to mitigate the results of a fault - e.g. to contain any resulting overheating or fire).

   - Andy. 

What I wonder is then how such distribution blocks like these Weidmüller AWPD 35 4X6/6X2.5 are safe:

Such blocks are often used as Neutral commoning blocks - in such cases the smaller conductors will be protected by the OPDs on the corresponding L conductors (ignoring faults between conductors of differing circuits, which is usually the case).

Where they're used on Line conductors, there will usually be downstream overcurrent protection which will protect the smaller conductors from overload and fault protection is either provided by an upstream device (in general an OPD will provide fault protection to much smaller conductors than it could provide overload protection for), or fault protection is omitted (most standards have provision for that - e.g. where the connections are short, precaution are taken to minimise the chances of a fault occurring, and precautions are taken to mitigate the results of a fault - e.g. to contain any resulting overheating or fire).

   - Andy.