GB 50057-2010 第6.4.1条
| The total resistance of the bonding conductor between the lightning protection equipotential bonding bar and the grounding device in the hotel shall not exceed 0.5Ω (including the resistance of the bonding conductor itself and the contact resistance). The bonding conductor shall be connected by welding or bolted compression; the weld length shall be not less than 6 times the diameter of the round steel or 2 times the width of the flat steel.