GB 50057-2010 第4.3.1条
| **** | **Down-conductor spacing**: For Class II lightning protection hotel buildings, the average spacing of down-conductors shall not exceed **18m**; for Class III lightning protection hotel buildings, the average spacing of down-conductors shall not exceed **25m**. Down-conductors shall be arranged evenly and symmetrically around the building perimeter, with priority given to using the building's steel structure or the reinforcement within concrete columns. |