The earth protection measures are introduced, and the measured grounding resistance is not greater than 1ω.
(1) The grounding grid must be connected with all down leads with steel bars or round bars not less than φ 10, and all down leads should be connected in series.
(2) When the steel bars in the grounding grid are bound, two overlapping steel bars shall be welded; Cross steel bar connection is adopted.
Not less than φ 10 steel bar or round steel jumper connection; The bending radius of the jumper bar should not be less than 10d, and it should not be less than 6d under special circumstances.
(3) When welding the grounding grid, the weld length should be ≥6d when double-sided welding is adopted, and ≥ 12d when single-sided welding is adopted.
All welds must be full.
(4) Equipotential grounding points are reserved for strong and weak wells, elevators and various computer rooms, and 40×4 galvanized flat steel is adopted.
lead-in (wire)
(1) Use two vertical steel bars not less than φ 16 (or four vertical steel bars less than φ 16 and greater than φ 10) to connect with ground beam steel bars and column steel bars.
(2) Jumpers shall be welded with round steel not less than φ 10, and the length of double-sided weld shall be greater than the diameter of round steel by 6d, and the length of single-sided weld shall be greater than 12d.
The bending radius of round steel is 6 days larger than the diameter of round steel, so it is easy to find traces with paint.
(3) The cold lap joint of the main reinforcement must be welded, and the threaded connection must be welded with jumper wires. When the main reinforcement is connected by pressure welding, its joint is welded.
Jumpers and other welding processes are not needed.
(4) The down lead spacing of lightning protection buildings of Category I to III shall not exceed 12m, 18m and 25m respectively.
equipotential
Equipotential mainly includes total equipotential bonding (MEB), auxiliary equipotential bonding (SEB) and local equipotential bonding (LEB).
(1) The equipotential bonding terminal board and connecting wires should be made of copper, and their cross-sectional areas must meet the requirements of the specification. In general,
On the premise of meeting the mechanical strength, the cross-sectional area of the equipotential terminal board should not be less than the cross-sectional area of the connecting wire; Cross-sectional area of connecting line
Not less than? S(PE line)
, the specific situation needs to be determined according to the actual situation.
(2) In general, equipotential bonding installation of metal pipe joints does not need bridging, and jumper wires need to be added at the water meter in the water supply system;
For the incoming power supply, it is necessary to do equipotential bonding by yourself, and all equipotential bonding systems should be connected nearby.
Electrify the whole building
The devices are at the same potential level; For the equipotential connection of the bathroom, if there is no PE line in the bathroom, the part in the bathroom, etc.