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Bonding and earthing: static electricity. Can you help a fellow member of the Voltimum community find a solution to their problem?
Question:
I've been asked to install an earth connection to a number of above-ground steel storage tanks to reduce the risk of static electricity caused by liquid transport/movement. HS(G)176 paragraph 152 states that a maximum resistance of 10 ohms to earth is recommended and it should be possible to disconnect the earthing facility for periodic testing. EEMUA Publication 159 paragraph 8.9 states that an earth conductor connected to the tank should to connected to one or more earth electrodes. These tanks stand on solid concrete foundations. My thoughts are to install a local EMT (earth marshalling terminal) and run say a 25mm G/Y copper conductor to each tank.
My question is: can I then connect this EMT to the earth bar in a local distribution board OR do I need to install an earth rod/s and connect it to that?