Looking at all the 3P MCBs, I presume that discrimination on earth faults, or per-circuit isolation, isn't a priority for the customer.

How does the double/reinforced insulation before the incomer look? (or is there an upstream RCD?)

   - Andy.

Looking at all the 3P MCBs, I presume that discrimination on earth faults, or per-circuit isolation, isn't a priority for the customer.

How does the double/reinforced insulation before the incomer look? (or is there an upstream RCD?)

   - Andy.

Customer would have no idea Andy, nor would it seem has the contractor. My view is a blatant disregard for 314.1, a regulation that is often swept under the carpet. Likely not a significant safety consideration but a real PITA for the client should the main RCD jump out. Twelve forecourt pumps fed from one of the 3P MCBs via an adjacent board. Oh and a 100mA RCD at intake some 20m away, no time delay and no overcurrent protection other than the DNO service head. The earth loop socket is wired correctly at least. 
Caveat Emptor and all that but perhaps clients will eventually realise contractors don’t usually make good designers!