Embedding of grounding flat steel 1) water supply and drainage, cable, wire and gas inlet (if the installation height of inlet pipe is relatively high, its grounding terminal can be reserved in the ceiling) 2) cable, information wire The telephone line enters the pipe (see installation of equipotential bonding (02d501-2) P12) 3) high and low voltage distribution room (at least 2 points) 4) the distribution cabinet in the pump room (it is recommended to surround the pump room and connect the conductors within the arm, see the provisions of the atlas) 5) the temporary distribution box 6) the distribution box in the basement, Outdoor distribution box 7) basement machine room (ventilator room, civil air defense fan room) 8) outdoor distribution box (such as outdoor advertising distribution box and roof outdoor advertising distribution box) 9) the first distribution box introduced outdoors (such as civil air defense distribution box) 10) elevator shaft 11) temporary construction elevator 5.
Its purpose is to facilitate the connection of metal doors and windows on the upper and lower floors within 6m height.
Find out the position of all main reinforcement according to the design requirements, mark it with paint, weld the disconnection clip at 0.5m away from the outdoor surface, weld it to the top layer in series with the reinforcement layer by layer, and weld a certain length of down lead on the roof Ф 12mm galvanized round steel for connection with lightning strip.
All upward pipe orifices and junction boxes buried in the concrete must be sealed tightly to prevent sundries from entering the pipe.
Lightning protection construction 1.
After the foundation grounding project is completed, the grounding resistance test shall be conducted at the outgoing line of each grounding electrode.
The construction quality requirements of lightning protection grounding.
3、 Electrical piping (I) structural piping 1.
The embedded pipes shall be prefabricated in advance.
The spacing between the fixed points of PVC pipeline shall not be greater than 1m, and the distance from the end and bending midpoint shall not be greater than 500mm.
The grounding resistance R is required to be less than 1 ohm.
When the main reinforcement in the structural column is used as the down lead, each down lead shall not be less than two main reinforcements, and the diameter of each main reinforcement shall not be less than Ф 16mm, the lightning protection downlead position should be symmetrical Distance between downleads: class I lightning protection building: ≤ 18m; Secondary lightning protection building: ≤ 20m; Class III lightning protection building: ≤ 25m.
The equipotential equipotential method adopts the welding of two main reinforcements in the ring beam around the toilet, The surface reinforcement of the toilet bottom plate is welded into a grid according to 600 * 600 span and connected with the reinforcement of the vertical and horizontal ring beam.
The weld at the welding position shall be full and have sufficient mechanical strength, and there shall be no slag inclusion, undercut, crack, false welding, pore and other defects.
In design, the grading ring can be welded into a closed ring by using two main reinforcements in the ring beam, which must be connected with all downleads.
Except that the welding points buried in the concrete are not treated, the other welding points shall be taken with anti-corrosion measures: brush one layer of antirust paint and two layers of silver powder paint.
The welding of lightning protection grounding adopts lap welding, and the lap length shall comply with the following provisions: the lap length of round steel and round steel shall not be less than 6 times the diameter of round steel, and welding shall be carried out on both sides (when the diameter is different, the lap length shall be subject to the larger diameter); When the round steel is overlapped with the flat steel, it shall not be less than 6 times the diameter of the round steel, and it shall be welded on both sides; The overlap between flat steel and flat steel is that the flat steel shall not be less than 2 times of its width and shall be welded on no less than three sides (when the width of flat steel is different, the overlap length shall be subject to the width); When flat steel is welded with steel pipe or angle steel, it shall be close to the surface of 3 / 4 steel pipe or close to the two sides outside the angle steel, and the upper and lower sides shall be welded.
When pouring and tamping concrete, the buttress shall be protected.
2.
The pipeline and the bottom reinforcement shall be bound firmly with iron wire to avoid the displacement and damage of the pipeline.
The downlead in the column shall be reliably welded with the grading ring in the beam, which adopts double-sided welding.
1、 Foundation Grounding 1.
After the welding of each lead-in point on each floor and before concealment, the on-site constructor and supervisor shall be invited to carry out concealed inspection, and the concealed inspection record shall be filled in at the same time.
Grading ring grading ring is a horizontal lightning strip around the building designed by the high-rise building to prevent side lightning.
The bending radius of the pipe and the number of additional transfer boxes shall be in strict accordance with the national specifications.
Electrical pipes shall be embedded.
After welding, the coating shall be removed.
The grounding body (wire) shall be connected by welding.
The process flow grounding device uses two main reinforcements at the opposite corners of the inner (peripheral) ring beam of the building foundation to weld into a ring network (four main reinforcements must be used if the main reinforcement is less than ø 12), and the downlead is welded into one with the ring network.
To prevent the root of the electric tube from being bent and broken, a special lock head (cup comb) shall be used for the pipe entering the box, and a cushion block shall be plugged under the lock nut to prevent the lock nut from being stepped off or disconnected..
The box must be positioned accurately, the box end face is closely attached to the template, and the box is filled with waste paper and foam board, and the red paint is used as a mark.
This paper is compiled according to an actual high-end residential project in country garden, which has great practical guiding significance.
Lightning protection test point 4.
2.
The double-sided welding length of the weld shall be greater than 6D, and the lower end shall be welded with the two main reinforcements of the building pile foundation reinforcement and the foundation bottom beam reinforcement.
3.
The buried pipeline shall be laid along the shortest path to minimize the number of turns.
Country garden requires a grading ring on the 10th floor, and then a grading ring on every two floors.
In architectural design, when the height exceeds the radius of the rolling ball (30M for class I, 45m for class II and 60m for class III), a grading ring shall be set every 6m.
A – 25 * 4 galvanized flat steel is welded by the ring beam to connect the local equipotential box of the toilet (300mm from the ground).
After the coating at the welding position is knocked clean, anti-corrosion treatment shall be carried out.
Lightning rod the setting law of lightning rod is generally: the highest point and prominent point, such as ridge, eaves corner, flat roof and wall corner.
If it fails to meet the requirements, the manual grounding electrode shall be added until it meets the requirements.
The welds of the welding points shall be full and free from slag inclusion, undercut, false welding, pores and other defects.
If the embedded pipe box is damaged, the socket pipe bent from the ground to the slab surface shall be repaired in time.
II.
Special personnel must be assigned to strengthen the protection of PVC pipes during concrete pouring to prevent displacement or damage during vibration; The personnel on duty must watch until the concrete pouring and tamping is completed, and shall not leave the post halfway.
