4.3　The Types of Internal Equipotential Bonding

4.3.1　The star-mesh mixed earthing configuration shall be adopted in telecommunication bureaus （stations），which shall meet the requirements of Appendix D of this code.

4.3.2　The mixed earthing connection in the mode of ring main earthing conductor may be designed according to Fig.4.3.2.

Fig.4.3.2　Mixed earthing connection in mode of ring main earthing conductor

4.3.3　After buildings adopting equipotential bonding measures，each equipotential bonding network shall have reliable connection directly to the earth with the common earthing system.For the equipotential bonding system of each sub telecommunication system，the individual down-conductor system connected to the main earthing bar should no longer be set，and instead the equipotential bonding system should be led to the floor earthing bar of the same floor via the earthing conductor.