A meter board is assembled from partly cabled building blocks. The cabinet (6) is one such block. The panels or bays (30) and the upper terminal chamber (31) form another and the lower terminal chamber is a third. The assembly is by plug connectors at the top and bottom of the back wall of the cupboard. The connectors are shaped like a knuckle with a circular tongue on one side and a retainer for this on the other side. The tongue and retainer are each at one end of a transverse bar of the unit and both abut each other in the final connection. The lower terminal chamber has a profiled section on its left and right sides.
