4.8　The Earthing of Other Facilities

4.8.1　Various metal facilities at the roof must be separately connected with the nearby roof lightning strips or preinstalled earthing terminals.

4.8.2　Power lines for roof aviation obstruction beacon，colored lamps，aviation obstruction beacons at the telecommunication tower of wireless telecommunication system and other electric equipment shall adopt metal sheath cables.Cable metal protective coverings or metal pipes，which are laid horizontally，shall be connected with the nearby lightning strips or earthing conductors at an interval of 5m-10m.Cable metal protective coverings，which are laid in up and down direction，shall be earthed nearby at least once at the upper end or the lower end.

4.8.3　Metal pipelines at each floor in the building shall be earthed at the place nearby.The upper and lower ends of elevator slideways in the buildings shall also be earthed at the place nearby，besides，the elevator slideways should be earthed every other floor，starting from the place where the distance to the ground is over 30 meters.

4.8.4　The electrical connection shall be made for all sections of metal vertical shafts and metal channels in the building.The upper and lower ends of the metal vertical shaft shall also be earthed at the place nearby，besides，the metal vertical shaft should be earthed every other floor，starting from the place where the distance to the ground is over 30 meters.Metal channels shall also keep good connection with racks or reinforced steel beams.

4.8.5　Signal vertical shafts at the comprehensive telecommunication building should be designed at the middle of the building.