Connection of roof equipment.
Manual grounding devices or grounding devices using building foundation reinforcement must set test points above the ground according to the design requirements.
After welding, the coating shall be knocked off and marked with paint.
Equipotential wiring in toilet.
When round steel is used to lap the lightning strip, the reinforcement should be connected up and down, which is more beautiful.
In this paper, seven important processes of lightning protection and grounding construction are illustrated in detail for your reference and comparison to guide construction or inspection.
Not less than 1×2.5 ㎜ ² Equipotential bonding (concealed laying through pipes) of BV conductor; 3.
Connection of roof metal pipes.
05 roof metal lightning protection connection roof metal ladder lightning protection connection.
1.
The lightning strip and lightning downlead shall be reliably connected and used in the roof protective layer Φ 12.
The lightning strip shall be welded with the building down lead.
Because of its strong professionalism and many concealed works, it is often a difficulty in building engineering.
The reinforcement is welded to the parapet on the top floor in series layer by layer, and the upper end of the downlead is connected with the lightning strip.
Except for the welded joints buried in concrete, anti-corrosion measures should be taken.
The lightning rod and wall lightning strip shall be in correct position, the welding seam fixed by welding shall be full without omission, the anti loose parts such as caps fixed by bolts shall be complete, and the anti-corrosion paint applied on the welding part shall be complete.
The equipotential bonding in the bathroom shall not be connected with the PE line outside the bathroom to prevent the introduction of dangerous potential in case of failure..
When there are no requirements in the design, when the lightning strip is exposed, the height of the support is 10 ~ 20 cm, the spacing of its fulcrum is uniform, which should not be greater than 1m, and the spacing of fulcrum at the corner is 0.3 ~ 0.5m.
02 the down lead grounding main line shall be welded with the reinforcement connected with the grounding body.
06 connection between equipotential bonding wire and various metal pipelines (except gas pipelines) (as shown in the schematic diagram): select a special hoop (made of galvanized flat steel or copper strip) according to the outer diameter of the pipeline, put the hoop on the pipeline, and firmly connect it with the equipotential bonding wire through bolts, nuts and spring washers of corresponding specifications.
The supports on both sides of the corner are 300 mm away from the corner center.
To prevent lightning current from generating sparks in the gas pipe, spark discharge gaps should be bridged at both ends of this insulation section.
When the independent foundation is used as the grounding device, the lead-in wire is welded with the two reinforcements inside and outside the bottom plate to form a loop.
03 grading ring the grading ring should adopt round steel with a length of about 28 cm to weld the two main reinforcements of the peripheral structure into one.
However, the total length shall not exceed 10mm; The bending of lightning protection network shall not be less than 90 °, and the bending radius shall not be less than 10 times the diameter of round steel; If flat steel is used for lightning protection network, the sectional area shall not be less than 48 mm ²； If round steel is used, the diameter shall not be less than 8mm.
When the foundation is grounded, welding marks can be made on the raft to prevent overlapping errors.
Connection between equipotential bonding wire and gas pipeline (as shown in the schematic diagram): to avoid using gas pipeline as grounding electrode, an insulating section (such as insulating plate between flanges) should be inserted into the gas pipeline after entering the house to isolate it from the outdoor buried gas pipeline.
Use column main reinforcement [2 ≥ Φ 16 (column main reinforcement ≥ Φ 16) Or 4 pieces ≥ Φ 10 (main reinforcement of column< Φ 16) When making the downlead, use the connected main reinforcement in the column Φ 12 round steel shall be bridged and welded to make it a good lightning protection lead.
The lightning strip shall be bended at the deformation joint for compensation.
The weld should be full.
There should be no slag inclusion, overlap, false welding, undercut and other phenomena at the welding lap.
The cross-sectional area of equipotential downlead shall not be less than 80 mm ²， Galvanized flat iron or galvanized round steel is used to reliably connect with the reinforcement mesh of the building on this floor; 2.
04 the lightning strip of the lightning arrester should be straight and firm, without ups and downs and bending, and the distance from the building should be consistent.
Welding method can also be used for thick wall metal pipes with design permission.
The allowable deviation of the flatness every 2m inspection section is 3/1000.
The galvanized round steel divides the roof plane into grids of no more than 20m*20m or 24m*16m.
During installation, wipe the contact surface between the hoop and the pipeline.
Schematic diagram of lightning protection and grounding system construction process whole process lightning protection and grounding construction process: grounding device → concealed laying of down lead (or exposed laying of down lead) → grading ring → lightning strip or lightning network → equipotential and indoor grounding trunk line → installation and testing of grounding test points 01 when grounding device uses building raft reinforcement as grounding body, more than 2 main reinforcements (diameter not less than Φ 16) Weld through, weld the intersection with each other, and reliably weld with the two main reinforcements in all passing concrete piles, and make bow connection at the building deformation joint.
Main reinforcement less than φ Four pieces shall be used for 16mm.
According to the design requirements of the drawing, the grading ring and the downlead shall be reliably lap welded.
Lightning protection and grounding is an important sub project in building electrical engineering.
The exposed metal objects protruding from the building need to be connected for lightning protection: the parts that cannot be welded should be connected with special grounding screws.
When equipotential and lightning strip are connected by welding, lap welding should be adopted and the following requirements should be met: when round steel is connected with round steel, welding should be carried out on both sides, and the lap length is 6 times the diameter of round steel; When flat steel is connected with round steel, it should be welded on both sides, and the lap length is 6 times the diameter of round steel; When the flat steel is connected with the flat steel, it should be welded on three sides (three edges), and the lap length is twice the width of the flat steel (when the width of the flat steel is different, the lap length is subject to the width).
In combination with the drawings, galvanized flat iron shall be reserved in the elevator shaft, pipe shaft and other places where grounding points need to be reserved.
The lightning rod and wall lightning strip on the top of the building must be connected with other metal objects exposed on the top to form an integral electrical path, and be reliably connected with the lightning downlead.
