About this deal
The distributor may require a minimum size of earth conductor at the origin of the supply of 16mm² copper or greater for TN-S and TN-C-S supplies. Protective conductors (including earth and bonding conductors) of 10mm² cross-sectional area or less shall be of copper.
16.0mm 6242Y Twin and Earth Cable - Edwardes
The most typical method chosen is selection, in accordance with table 54.7 and the size selected is based on the cross-sectional area of the line conductor. For 25mm tails this results in a 16mm main earth. Using regulation 543.1.3 and the calculation method, the size of the protective conductor chosen is typically smaller than through selection. In the situation, you describe the calculation would need to be completed to determine whether the earthing conductor is adequate. The size of an earthing conductor shall be in compliance with regulation 543.1.1. This requires either:
The main protective bonding conductors shall have a cross-sectional area of not less than half that required for the earthing conductor and not less than 6mm². is a non standard size protective conductor size, so the next size up is 10mm2 is acceptable, which saves money installing a 16mm2. I have an install involving 3 four core SWA of 240 mm2 feeding an MDP from a generator.The load is 1200 amps. Would I consider sizing it to half of the combined area of the 3 (240mm2) size as in half of 720 mm2 or half of each 240mm2 .
Cable - 6mm, 10mm and 16mm - TLC Direct 6491X Single Core Cable - 6mm, 10mm and 16mm - TLC Direct
When calculating the size of the protective conductor do I use Table 54.7 or the Aidabatic equation? c) Where practicable, the connection to the gas, water, oil, etc service should be within 600mm of the service meter, or a point of entry to the building if the service meter is external and must be on the consumer’s side before and branch pipework and after any insulating section in the service. The connection must be made to hard pipework, not to soft or flexible meter connections. b) Bonding connections to incoming metal services should be made as near as practicable to the point of entry of the services into the premises, but on the consumer’s side of any insulating section. This 16mm² Single Core Earth Cable is suitable for power and lighting circuits, building wiring, use in conduits and closed installation ducts and internal appliance wiring. The 6491X cable comes in a 50m drum.