Main switch room as ingress of dust , the switch room also has many openings to allow the ingress of dust. A recent EICR as coded the Distribution equipment in the room C2 not fit for external influences . One side of the room as an 800A BS 5709 isolator supplying a busbar with 10 BS 5709 isolators supplying various pieces of equipment. Can’t find a decent IP65 MCCB board. Or could holes be sealed in the switch room to minimise the ingress of dust (they should have be done to prevent the spread of fire) and an IP44 MCCB DB used.