A contractor has provided the single-phase electrical installation in 12 new, very small, individual commercial units. For whatever reason he provided two 6way distribution boards one appears to be for lighting and the like and the other for power, both with 30mA overall RCD protections both boards have a main switch. The tails for both boards are brought to a set of ISCOs from which he left a short tail connection for the meter. Now 4 of the units have been connected to the supply but apparently connection is being refused to the remaining units as no main switch has been provided. I guess different DNOs, different rules and indeed attitudes but I can find no reference to the need for a main switch in the DNO connection guide other than that the installation has to comply with 7671.