Abstract:

Rational equipotential bonding is fundamental for Metro works so as to reduce the risk of electric shocks in Metro stations. In the paper, 3 equipotential bonding manners commonly used in Metro stations, i.e., connection between local equipotential terminals and earthing busbar, auxiliary equipotential bonding, and connection between local equipotential bonding terminal box and structural reinforcement bars, are analyzed, the disadvantages of these 3 bonding manners are discussed, and a rational equipotential bonding manner, i.e., a combination of auxiliary equipotential bonding and local equipotential bonding, is proposed on basis of relevant standards. In the end, the electric shock has been effectively avoided. It is also concluded that the local equipotential bonding terminal board should not be interconnected, and it is unnecessary to set additional earthing cable to connect the earthing busbar.

Key words: equipotential bonding, Metro station, protective earthing, earthing fault