Where a metering enclosure is remote from the main switchboard, the enclosure needs to be effectively earthed by either of two methods.
The enclosure is bonded to the consumer mains neutral on the load side of the meter by an earthing conductor, with a cross sectional area not less than the consumer mains neutral conductor. The neutral conductor must be continuous and the connection be made by splicing and soldering or the use of a two screw connector.
This method must not be used where the metering enclosure and the main switchboard are attached to the same metal frame of the building structure.
The enclosure is bonded to the earth bar of the main switchboard via an earthing conductor of the same cross sectional area as the consumer mains neutral.
This method must be used when the metering enclosure and the main switchboard are attached to the same metal frame of the building structure.