1. General Provisions
1. Project overview
The office building of the RESEARCH and Development Base of XX Design Institute of China Power Engineering Consulting Group (hereinafter referred to as the building) is located in the southwest corner of Tuanjie South Road and The intersection of Science and Technology 4th Road in Xi'an High-tech Development Zone. The main structure is 11 floors above ground, 1 floor underground, the height is 44.85m, the frame shear wall structure, the construction area is about 34900m2 (including the underground garage area of about 8000m2), the building is mainly used for xx design institute research and development base production management office space, the building belongs to the second class of lightning protection.
2. Scope of application
Applicable to xx design institute R & D base office building lightning protection grounding system engineering.
3. The standards and norms on which the preparation is based
GB 50303-2015 Construction Quality Acceptance Specification for Building Electrical Engineering.
2. Construction preparation
1. Material requirements
(1) Galvanized steel has flat steel, angle steel, round steel, steel pipe, etc., when using it should be cold galvanized or hot-dip galvanized material, there should be technical parameters when required should meet the design regulations. The product should have a material inspection certificate and a product factory certificate, and do a good job of acceptance records and acceptance data archiving.
(2) Galvanized accessories include lead wire (i.e. galvanized iron wire), bolts, washers, spring washers, U-bolts, yuanbao bolts, brackets, etc.
(3) Welding rods, oxygen, acetylene, asphalt paint, concrete brackets, buried iron parts, small wires, cement, sand, plastic pipes, red paint, white paint, anti-corrosion paint, silver powder, black paint, etc.
2. Main tools
(1) Commonly used electrician tools, hand hammers, hacksaws, saw blades, pressure cases, shovels, pickaxes, sledgehammers, rammer barrels,
(2) Wire drops, tape measures, large ropes, powder wire bags, grinding (or inverted chains), wire tighteners, electric hammers, impact drills, welding machines, welding tools, etc.
3. Working conditions
(1) Grounding body operating conditions.
1) Clean up the site according to the design location
2) The connection between the bottom plate rib and the column rib has been tied.
3) The connection between the reinforcement and the column rib in the pile foundation has been tied.
(2) Grounding trunk line operating conditions:
1) The bracket is installed.
2) The protective tube has been pre-buried.
3) Civil plastering is completed.
(3) Bracket installation working conditions:
1) Various brackets have been shipped to the site.
2) The structural works have been completed.
3) There must be scaffolding or climbing ladders outdoors.
(4) Lightning protection downline dark laying operating conditions:
1) The building (or structure) has scaffolding or climbing ladders to meet the conditions for human operation.
2) When using the main rib as the lead line, the steel bar is tied.
(5) Lightning protection leads down the line laying operating conditions:
1) The bracket is installed.
2) Buildings (or structures) have scaffolding or climbing ladders to meet the conditions for human operation.
3) The decoration of the civil construction is completed.
(6) Lightning protection belt and pressure equalizing ring installation operating conditions: when the civil ring beam steel bar is being lashed, cooperate with this work.
(7) Lightning protection net installation operating conditions:
1) The grounding body and the lead wire must be done.
2) The bracket is installed.
3) Have suitable site adjustment and vertical transportation conditions.
(8) Lightning rod installation operating conditions:
1) The grounding body and the lead wire must be completed.
2) The scaffolding and scaffolding are required.
3) The civil structural engineering has been completed, and the embedded parts have been completed with the structural construction.
Third, the operation process
1. Process flow
Lightning rod grounding body → grounding → line bracket→ lead down the line open → lightning protection belt or lead down line dark → pressure equalization ring.
2. Grounding body installation process
The installation of artificial grounding bodies (poles) shall comply with the following regulations:
(1) The minimum size of the artificial grounding body (pole) should meet the requirements of the specification.
(2) The burial depth of the grounding body should be no less than 0.6m at the top, and the angle steel and steel pipe grounding body should be vertically configured
(3) The degree of vertical direct earth body should not be less than 2.5m, and the spacing between them should generally not be less than 5m.
(4) The location of the grounding body should not be less than 1.5m from the building; when the grounding body is buried in garbage ash, the soil should be changed and tamped in layers.
(5) When the grounding device must be buried less than 3m from the entrance or sidewalk of the building, the method of equalizing belts should be adopted or a 50~90mm thickness asphalt layer should be laid on the grounding device, and its width should exceed 2m of the grounding device.
(6) The connection of the grounding body (line) should be welded, the weld should be full and have sufficient mechanical strength, there must be no slag, biting, cracking, virtual welding, porosity and other defects, after the skin of the weld is knocked clean, brush asphalt for anti-corrosion treatment.
(7) When lap welding is adopted, the welding length is as follows:
1) Galvanized flat steel is not less than 2 times its width, welded on three sides. (When the width of the flat steel is different, the lap length shall be the width). The flat steel before laying needs to be straightened, the simmering bend must not be too dead, there should be no obvious bending on the straight line section, and it should be placed upright.
2) The welding length of galvanized round steel is 6 times its diameter and should be welded on both sides (when the diameters are different, the lap length shall be subject to the large diameter).
3) When galvanized round steel is connected with galvanized flat steel, its length is 6 times the diameter of round steel.
4) Galvanized flat steel and galvanized steel pipe (or angle) welding inch, in order to be reliable connection, in addition to welding on both sides of its contact part, the flat steel should also be directly bent into an arc (or right angle) and steel pipe (or angle) welding.
(8) When the grounding line encounters a layer of white ash scorched slag and cannot be avoided, the cement mortar should be used for full protection.
(9) When using chemical methods to reduce soil resistivity, the materials used should meet the following requirements:
1) Weak corrosiveness to metals;
2) Low content of water-soluble ingredients.
(10) All metal parts should be galvanized. When operating, pay attention to the protective galvanizing method.
3. Artificial grounding body (pole) installation
(1) Processing of grounding bodies. According to the number of design requirements, material specifications for processing, the material is generally cut with steel pipe and angle steel, and the length should not be less than 2.5m. If the steel pipe is used to penetrate into the ground, it should be processed into a certain shape according to the soil quality, and when it encounters soft soil, it can be cut into a bevel shape. In order to avoid uneven force during entry and tilt the pipe, it can also be processed into a flat-pointed shape, and when the soil is very hard, the tip can be processed into a tapered shape. If the angle steel is selected, the angle steel should be not less than 40mmx40mmx4mm, the cutting length should not be less than 2.5m, and one end of the angle steel should be processed into a pointed shape.
(2) Trenching: According to the requirements of the design drawing, the line of the docking body (net) is measured, and the trench with a depth of 0.8 to 1m and a width of 0.5m is excavated on this line, and the upper part of the ditch is slightly wider, and if there is any stone at the bottom, it should be removed.
(3) Installation of grounding body (pole): After the ditch is dug, the grounding body and grounding flat steel should be installed immediately to prevent the earth from collapsing. First put the grounding body on the center line of the ditch, into the ground, generally use a hand hammer to hit the person, one person to support the grounding body, one person with a sledgehammer to hit the top of the grounding body, in order to prevent the steel pipe or angle steel splitting, you can add a protective pipe cap into the grounding pipe end, the angle steel grounding can be used short angle steel (about 1mm) welded in the grounding angle steel one, the use of hand hammer to hit the grounding body should be stable, the hammer grounding body is in the middle, not deflected, should be kept perpendicular to the ground, when the top of the grounding body is 0.6m away from the ground to stop punching.
(4) Fan steel laying between the grounding bodies: The flat steel should be straightened before laying, and then the flat steel is placed in the ditch, and the flat steel is welded with the grounding body by electric welding (gas welding) in turn. Flat steel should be placed sideways but not flat, and the scattering resistance is small when side-placed. The position where the flat steel is connected to the steel pipe is about 100 mm from the highest point of the grounding body. When welding, the flat steel should be straightened, the chemical skin should be removed after welding, the asphalt should be brushed for anti-corrosion treatment, and the ground wire should be led out to the desired position, leaving enough connection length for use.
(5) Verification of the grounding body (line): after the grounding body is connected, the quality inspection department should be asked to carry out hidden inspection, grounding body material, location, welding quality, etc. The cross-sectional specifications of the grounding body (line) should meet the requirements of the design and construction acceptance specifications, and can be backfilled after passing the inspection, and the layered compaction should be carried out. Finally, fill in the ground resistance shake value on the hidden inspection record.
4. Natural foundation grounding body installation
(1) Use non-waterproof bottom plate reinforcement or deep foundation as the grounding body.
Use non-waterproof bottom plate reinforcement or deep foundation to do the grounding body: according to the design drawing size position requirements, mark the position, and weld the bottom plate steel reinforcement lap welding. Then the bottom of the column main rib (not less than 2) and the bottom plate rib are welded, and the main welding plate is welded below the outdoor ground to eliminate the drug skin, and the two main ribs are marked with color paint for easy introduction and inspection. The quality inspection department should be asked to conduct a hidden inspection in a timely manner, and at the same time make a record of the hidden inspection.
(2) Use the cylindrical pile foundation and platform reinforcement to do a good job of grounding, according to the size of the design drawing position, find the position of the number of pile base groups, weld each group of pile foundation four-corner rebar lap welding, and then weld with the column main rib (not less than 2), and below the outdoor ground, the main rib is buried in the grounding connection plate, remove the chemical skin, and the two main ribs are marked with color paint, which is convenient for introduction and inspection, and should be timely asked to the quality inspection department for hidden inspection, and at the same time make a hidden inspection record.
5. Installation of grounding trunks
(1) When the grounding trunk line passes through the wall, it should be protected by a casing, and when crossing the expansion joint, it should be simmered and compensated.
(2) The grounding trunk should be equipped with a disconnection card prepared for measuring the grounding resistance, which is generally installed in a cassette, and the box cover is added and the grounding mark is made.
(3) When the grounding trunk line crosses the doorway, it should be secretly laid in the ground (buried before making the ground).
(4) The grounding trunk line should be no less than 200mm from the ground, the distance from the wall should be no less than 10mm, the support parts should be 40mmx4mm flat steel, the tail end should be made into a dovetail shape, the depth and width of the hole are 50mm each, and the total length is 70mm. The horizontal straight-line distance between the support parts is generally 1m, the vertical part is 1.5m, and the turning part is 0.5m.
(5) The grounding trunk line should be laid straight, and the allowable deviation of horizontality and verticality is 2/1000, but the total length shall not exceed 10mm.
(6) The bending middle diameter of the grounding trunk at the corner shall not be less than 2 times the width of the flat steel.
(7) The grounding trunk should be brushed with black paint, and the paint should be uniform and non-omission, but the paint should not be brushed at the broken connection card and the grounding terminal.
6. Grounding trunk line installation
The grounding trunk line should be connected with the flat steel connected by the grounding body, it is divided into two kinds of indoor and outdoor connections, the outdoor grounding thousand lines and branch lines are generally laid in the trench indoor grounding trunk line is mostly open, but some of the branch lines connected by equipment need to pass through the ground, and can also be buried in concrete. The specific installation method is as follows:
(1) Outdoor grounding trunk laying:
1) First of all, straightening, positioning, eye punching, simmering and bending of the grounding wide line are carried out, and the broken connection card and grounding terminal are installed.
2) Before laying, dig the trench according to the size position required by the design. Digging a trench requires seeing the above, and then laying flat steel and burying it. The backfill soil should be compacted but not rammed, and the exposed ground at the end of the grounding trunk should not exceed 0.5 m in order to connect the ground wire.
(2) Indoor grounding trunk line laying:
1) Reserved hole and buried support: according to the design requirements of the size position, reserve the grounding wire hole, the size of the reserved hole should be more than 6mm more than the thickness and width of the grounding trunk. There are three methods: (1) During construction, a section of flat steel can be pre-buried in the wall according to the above requirements, and when the concrete has not yet solidified, the flat steel is twitched so that it is easy to extract after solidification. (2) The flat steel is wrapped with a layer of linoleum or several layers of kraft paper and buried in the wall, and the dam hole should be 15 to 20mm from the wall surface. (3) The protective sleeve can be made of iron sheet with a thickness of more than 1mm to form a circle, and the size should make the grounding wire penetrate, and there is a gap of more than 6mm on each side.
2) Support fixed: According to the design requirements, first determine the coordinate axis position on the brick wall (or aerated concrete wall; hollow brick wall), and then with the masonry wall, the pre-made 50mmx50mm square wood model will be set on fire in the wall, and the square wood sample will be removed after the wall is built, and then the support parts will be put into the hole, and the water will be sprinkled to wet the hole, and then the support part will be buried with cement mortar, and then used after solidification. Fixed bracket on the cast-in-place concrete wall, first according to the design drawings to require the positioning of the bullet line, drilling, the bracket is dovetail buried in the hole, leveled, fixed with cement mortar.
3) Installation requirements for clear grounding wire:
(1) The laying position should not hinder the disassembly and maintenance of the equipment, and facilitate inspection.
(2) The grounding line should be laid horizontally or vertically, and can also be parallel to the straight line along the inclined structure of the building, and there should be no low undulations and bends.
(1) When the grounding line is laid horizontally along the wall of the building, the distance from the ground should be maintained 250~300mm, and the gap between the grounding line and the wall of the building should not be less than 10mm.
(2) The surface of the grounding wire of the Mingshiki should be coated with stripes of green paint and yellow paint of equal width of 15 to 100 mm, and its signs are obvious.
(3) At the entrance where the grounding wire leads to the entrance of the building or at the temporary grounding point for maintenance, it should be marked with a black symbol after a white primer, and its symbol is marked as "
"The signs are clear.
4) Open grounding wire installation: When the support parts are buried and the cement mortar solidifies, the grounding wire on the wall can be laid, the grounding flat steel can be hoisted along the wall, and the flat steel will be fixed with a card at one end of the support part, and the reserved hole should be crossed when passing through the partition wall, and the grounding trunk connection should be welded firmly. The end reservation or connection should meet the design requirements.
7. Lightning rod production and installation
(1) The production and installation of lightning rods should comply with the following provisions:
1) All metal parts must be galvanized, and attention should be paid to protecting the galvanized layer during operation.
2) The needle tip is made of galvanized steel pipe, the thickness of the pipe wall shall not be less than 3mm, and the length of the needle tip brush tin shall not be less than 70mm.
3) The lightning rod should be installed vertically and firmly, and the allowable deviation of verticality is 3/1000.
4) Welding meets the requirements of the specification, brush the anti-rust paint after removing the chemical skin.
5) The lightning rod is generally made of round steel or steel pipe, and its diameter should not be less than the requirements of the specification.
(1) Independent lightning rods generally use 19mm diameter galvanized round steel.
(2) The lightning rod on the roof is generally made of 25mm diameter galvanized steel pipe.
(3) The lightning rod at the top of the water tower adopts a galvanized steel pipe with a diameter of 25mm or 40mm.
(4) The lightning rod on the top of the chimney adopts 25mm diameter galvanized round steel or 40mm diameter galvanized steel pipe.
(5) Lightning protection ring with a diameter of 12mm galvanized round steel or a cross-section of 100mm2 galvanized flat steel, the thickness of which should be 4mm.
(2) Lightning rod production: according to the length of the material required by the design requirements, it is divided into three sections: upper, middle and lower sections for unloading. If the needle tip is made of steel pipe, you can first saw the upper section of the steel pipe into a serrated shape, after the hand hammer is sharpened, the weld is sharpened, the tin is shabu, and then the other end is straightened with the middle and lower two sections of steel pipe and welded well.
(3) Lightning rod installation: first fix the bottom plate of the support steel plate on the embedded anchor bolt, weld a rib plate, and then stand up the lightning rod, find straight, find the right, spot welding, and then correct it, weld the other two rib plates. Finally, the lead wire is welded to the bottom plate, and the anti-rust paint of the chemical skin brush is removed.
8. Bracket installation
(1) Bracket installation should comply with the following provisions:
1) Angle steel brackets should have dovetails, and their burial depth is not less than 100mm, and the burial depth of flat steel and round steel brackets is not less than 80mm.
2) All brackets must be firm, full of mortar, horizontal and vertical.
3) The top of the various brackets of the lightning protection device should generally be 100mm from the surface of the building; the top of the grounding trunk bracket should be 20mm from the wall.
4) The horizontal spacing of the bracket is not more than 1m (the concrete support is not more than 2m); the vertical spacing is not more than l.5m. The spacing should be uniform, and the brackets on both sides of the allowable deviation of 30mma should not be greater than 250mm from the center of the corner.
5) The stent should be straight. The horizontal degree is allowed to deviate from 3/1000 per 2m inspection section, and the vertical degree is allowed to deviate 2/1000 per 3m inspection section; however, the deviation of the full length shall not be greater than 10mm.
6) Iron parts such as brackets should be treated with anti-corrosion treatment.
7) The cement mortar used in the buried bracket should have a mix ratio of not less than 1:2.
(2) Bracket installation.
1) As far as possible, the bracket or iron part should be buried with the structural construction.
2) According to the design requirements for bullet line and gear positioning.
3) Use a hand hammer and hammer to remove the hole, and the size of the hole should be the same inside and out.
4) First bury the two ends of the bracket on a straight line, and then use the lead wire to pull the straight line to bury other brackets Before embedding, the hole should be wet with water.
5) If you use a concrete support, arrange the concrete support in gears, first pull a straight line between the two ends of the bracket, and then flatten the other supports with mortar to straighten.
6) If the daughter wall is reserved with embedded iron parts, the bracket can be welded directly on the iron part, and the straightening method of the bracket is the same as before.
9. Lightning protection leads down the line of dark laying
(1) The dark laying of lightning protection leads down the line shall comply with the following provisions:
1) The cross-section of the flat steel of the lead line shall not be less than 25mmx4mm; the diameter of round steel shall not be less than 12mm.
2) The lead line must be disconnected at 1.5 to 1 .8m from the ground (except for one lead down line). The diameter of the bolt used in the broken wiring card shall not be less than 10mm, and a galvanized washer and a galvanized spring washer shall be added.
3) When using the main rib as a dark lead line, each lead line shall not be less than two main ribs.
4) Cast-in-place concrete is laid down the line without anti-corrosion treatment. Welding meets the specifications.
5) The metal components of the building (such as fire ladders, iron ladders of chimneys, etc.) can be used as a lead line, but all metal parts should be connected to form electrical pathways.
6) The downline should be laid along the external wall of the building to connect the flasher to the grounding body, and the laying path of the lead line should be as short and straight as possible. It can also be bent when it is impossible to lead down in a straight line according to the specific conditions of the building, but it should be noted that the distance at the bending opening must not be equal to or less than 0.1 times the actual length of the curved segment. The lead line can also be installed darkly, but the truncated door should be increased by one level, and the distance of other metal components in the wall should also be paid attention to when darkly installed.
7) The distance between the fixed fulcrum points of the lead line should not be more than 2m, and a certain tightness should be maintained when laying the lead line.
8) The downline should avoid the entrances and exits of the building and the places that are more accessible to pedestrians to avoid danger.
9) In places prone to mechanical damage, a section of ground line from about 1.7m to 0.3m underground should be protected, in order to reduce the risk of contact voltage, bamboo cylinders can also be used to tie the lead wire up or wrap with insulating materials.
10) When using multiple open-mounted leads, in order to facilitate the measurement of ground resistance, as well as to test the connection between the lead wire and the ground wire, the grounding resistance should be measured at the end of the ground at 1.8 to 2.2m of each lead line.
11) Each building has at least two lead lines (except for buildings with a projection area of less than 50 m2). The lightning protection lead downline is preferably in a symmetrical position, the distance between the leads should not be greater than 20m, and when it is greater than 20m, one more lead downline should be led in the middle.
(2) Lightning protection downline dark laying method:
1) First of all, the required flat steel (or round steel) is straightened or straightened by hand hammer (or steel wrench).
2) The straightened lead line is transported to the installation site, and the building is introduced and hung according to the design requirements.
3) Timely weld the lower end of the lead wire with the grounding body, or connect it with the broken connection card. As the building gradually increases in height, the lead line is laid in the building up to the roof. If the joint is needed, it should be welded, and after welding, the chemical skin should be knocked off and brushed with anti-rust paint (except for cast-in-place concrete), and the relevant personnel should be asked to conduct a hidden inspection and record.
4) When using the main rib (diameter of not less than 16mm) as the lead line, find out all the main rib positions according to the design requirements, mark it with paint, weld the test point at 1 .8m from the outdoor floor, weld it layer by layer with the steel bar to the top layer by layer, weld out a certain length of lead line, the lap length should not be less than 100mm, after doing it, please ask the relevant personnel to conduct a hidden inspection and make a hidden inspection record.
5) After the civil engineering decoration is completed, the lower line is set on a section of 2m on the ground, and it is fixed firmly with a card and brushed with red and white paint.
6) The welding meets the requirements of the specification.
10. Lightning protection is laid under the line
(1) The laying of lightning protection leads down the line shall comply with the following provisions:
1) The vertical allowable deviation of the lead line is 2/1000.
2) The lead down line must be straightened and laid, and the bend should not be less than 90. , and must not be bent into a dead corner.
3) In addition to the special requirements of the design, the cross-section of galvanized flat steel shall not be less than 48mm2, and the diameter of galvanized round steel shall not be less than 8mm.
4) The position of the disconnection card should be carried out in accordance with the design and specification requirements.
5) The welding and lap length should be carried out in accordance with the relevant specifications.
(2) Lightning protection is laid under the line.
1) If the lead line is flat steel, it can be placed on the plate and straightened with a hand hammer; if it is a round steel leaf, the round steel will be released. One end is fixed to a fixture that is firmly anchored, and the other end is fixed to a clamp that is gripped (or inverted) for cold straightening.
2) Transport the straightened lead line to the installation site.
3) Lift the lead line with a large rope to the highest point, and then fix it point by point from the top to the factory until the broken connection card is installed. If a fitting or a disconnection clip is installed, it should be welded. After welding, remove the chemical skin, local straightening, brush anti-rust paint.
4) Put the grounding wire 2m above the ground, put on the protective tube, and snap and brush red and white paint.
5) Use galvanized bolts to connect the broken connection card with the grounding body firmly.
11. Lightning protection net installation
(1) The installation of lightning protection nets shall comply with the following provisions:
1) The lightning protection line should be straight and firm, there should be no high and low undulations and bending, the distance from the building should be consistent, and the straightness is allowed to deviate by 3/1000 per 2m inspection section. However, the total length must not exceed 10mm.
2) The bending place of the lightning protection line shall not be less than 90 °, and the bending radius shall not be less than 10 times the diameter of the round steel.
3) If the lightning protection line is made of flat steel, the cross-section shall not be less than 48mm; if it is round steel, the diameter shall not be less than 8mm.
4) The welding meets the requirements of the specification.
5) In case of deformation of the seam should be used as simmering compensation.
(2) Lightning protection net installation.
1) If the lightning protection line is flat steel, it can be straightened by hand hammer on the plate; if it is round steel, one end of the round steel can be fixed to the fixture with a firm anchor, and the other end can be fixed to the clamp of the grinding (or inverted chain) for cold pull straightening.
2) Transport the straightened lightning protection wire to the installation site.
3) The lightning protection line is lifted to the top with a large rope, straight, laid, stuck, welded into one, welded with the lower line, the skin of the weld should be knocked off, and after partial straightening, brush anti-rust paint and lead oil (or silver powder).
4) There are protrusions on the roof of the building, such as metal flagpoles, snorkels, metal gutters, iron railings, ladders, cooling water towers, TV antennas, etc., and the metal conductors in these parts must be welded with the lightning protection net. The top chimney should be used as a lightning rod or lightning rod.
5) Lightning protection should be done at the deformation joint of the building.
6) Lightning protection network is clearly divided into two kinds, the darker the net and the dark web, the better its reliability. The density of the grid should be determined by the lightning protection level of the building, the building with the high lightning protection level can use the 10mX10m grid, and the general building with the low lightning protection grade can use the 20mx20m grid, if the design has special requirements, it should be implemented according to the design requirements.
12. Installation of a pressure equalizing ring (or lightning protection belt).
(1) The pressure equalization ring (or lightning protection belt) should comply with the following provisions:
1) The diameter of round steel used in the lightning protection belt (lightning protection line) is generally not less than 6mm, and the flat steel is not less than 24mm x 4mm.
2) When the lightning protection belt is laid, the height of the bracket is 10~20cm, and the spacing of each fulcrum should not be greater than 1.5m.
3) For the parts of the building above 30m, a lightning protection belt is laid along the perimeter of the building every 3 floors and welded with each lead line.
4) Aluminum doors and windows and lightning protection device connection in the processing of ordered aluminum doors and windows should be thrown out of the 30cm aluminum strip or flat steel 2 places as required, such as more than 3m, it is necessary to connect 3 places. for crimping or welding.
(2) Installation of equalizing pressure ring (or lightning arresting belt).
1) The lightning protection belt can be secretly laid in the plastering layer on the surface of the building, or directly using structural reinforcement, and should be welded with the darkly applied lightning protection net or the steel bar of the floor slab, so the lightning protection belt is actually a pressure equalization ring.
2) The main rib or waist rib in the structural ring beam is welded into one with the pre-prepared connecting rebar head of about 20cm, and welded into a whole with the lead line in the column rib.
3) The points in the ring beam lead out of the steel head, after welding, with round steel (or flat steel) lay around, the ring beam welded each point, and with the surrounding leads to connect to form a ring, at the same time in the outside of the building along the metal doors and windows, metal railings throw out 30cm length and width 2mm galvanized round steel backup.
4) The embedded welding points of metal parts such as metal doors, windows, railings, handrails and other metal parts of the eaves should be no less than 2, and welded to the round steel reserved for the lightning protection belt as a whole.
5) When using the roof metal handrail railing as a lightning belt, the bend should be bent into a circular arc, and the railing should be reliably welded with the grounding lead.
(3) When the festival lantern is laid flat along the lightning belt, the height of the lightning strip should be higher than the top of the lantern, and when the lantern is laid vertically, the metal wire of the hanging lantern should be reliably grounded. At the same time, consideration should be given to installing a low-voltage lightning arrester or taking other lightning protection measures at the lantern control power box.
Fourth, quality standards
1. Guaranteed project
(1) The quality of the material meets the design requirements, and the grounding resistance value of the grounding device must meet the design requirements.
(2) Branch lines connected to the grounding of electrical equipment, appliances and other detachable non-live metal parts must be directly connected to the grounding trunk, and it is strictly forbidden to connect in series.
Inspection method: actual measurement or check ground resistance test record. Observe the inspection or check the installation records.
2. Basic items
(1) The lightning rod (net) and its support parts are installed in the correct position, fixed and well-protected; the outer body is vertical, the size and bending radius of the lightning arrest net are correct; the production quality of the lightning rod and support parts meets the design requirements The lightning rod lamp with the sign lamp is complete and clearly displayed. The lightning arrest net supports uniform spacing; the deviation of the verticality of the lightning rod is not greater than the diameter of the top outer rod.
Inspection method: observe inspection and actual measurement or check installation records.
(2) Grounding (zero) wire laying.
1) Straight, firm, uniform spacing between fixed points, compensation devices across the deformation joints of the building, protective pipes through the wall, and complete anti-corrosion of paint.
2) The weld seam of the weld connection is flat and full, and there is no obvious defect such as porosity and biting meat; the bolt connection is tight and firm, and there are anti-loosening measures.
3) The protective pipe of the lightning protection grounding lead line is fixed firmly; the broken wire card is set for easy detection, the contact surface is galvanized or tinned, and the bolts and other fasteners are all in place. Homogeneous corrosion protection, pollution-free buildings.
Inspection method: observation and inspection.
(3) Grounding body installation: the position is correct, the connection is firm, and the burial depth of the grounding body is not less than 0.6m from the ground. Concealed engineering records are complete and accurate.
Inspection method: Check the hidden engineering records.
3. Allow deviation items
(1) The lap length ≥ 2b; the round steel ≥ 6D; the round steel and flat steel ≥ 6D; where b is the flat steel width and D is the round steel diameter.
(2) Flat steel lap welding 3 edges, round steel welding double-sided.
Inspection method: ruler inspection and observation inspection.
Fifth, should pay attention to the quality of the problem
1. Grounding body
(1) The grounding body is buried deeply or the spacing distance is not enough, and it is implemented according to the design requirements.
(2) The welding surface is not enough, the chemical skin treatment is not clean, the anti-corrosion treatment is not good, the welding surface is corrected according to the quality requirements, the medicine skin is knocked clean, and the anti-corrosion treatment is done.
(3) The use of foundation, beam and column steel reinforcement overlapping area is not enough, should be strictly in accordance with the quality requirements to do.
2. Bracket installation
(1) The bracket is loose and the concrete support is unstable. Find the reason for the loosening of the bracket, and then fix it firmly; the concrete support is stable.
(1) The spacing between the brackets (or embedded iron parts) is uneven, the straight line segment is not straight, and the allowable deviation is exceeded, and the spacing is revised again, and the straight line segment is corrected and straightened, and the allowable deviation must not be exceeded.
(3) The welding port has defects such as slag clamping, biting meat, cracks, and porosity. Re-welding, the above defects are not allowed.
(4) The treatment of the drug skin at the weld is not clean, and the anti-rust paint that leaks the brush should be treated cleanly at the weld, and the anti-rust paint should be brushed.
3. Lightning protection leads down the line dark (bright) laying
(1) The welding surface is not enough, and the welding joint has the phenomenon of slag clamping, biting meat, cracks, pores and dirty treatment, etc., and should be repaired and changed according to the requirements of the specification.
(2) Leakage of brush anti-rust paint, should be repainted in time.
(3) The lead position of the main rib should be corrected in time.
(4) The lead line is not vertical, and the line exceeding the allowable deviation should be horizontal and vertical, and the deviation should be corrected in time.
4. Lightning protection net laying
(1) Welding is not enough, the welding joint has fire slag, biting meat, cracks, porosity and dirty treatment and other phenomena, should be repaired and changed according to the requirements of the specification.
(2) The anti-rust paint is uneven or there is a leakage of brush, which should be brushed evenly and the leakage of brush should be repaired.
(3) The lightning protection line is not straight, exceeding the allowable deviation, and should be horizontal and vertical after adjustment, and shall not exceed the allowable deviation.
(4) The card screw is loose, and the screw should be tightened in time.
(5) The deformation joint is not compensated and should be made up.
5. Lightning protection belt and pressure equalizing ring
(1) The welding surface is not enough, and the welding joint has slag, biting, cracks, porosity, etc., and should be repaired and changed according to the requirements of the specification.
(2) The grounding leads of steel doors and windows and iron railings are missing and should be filled in time.
(3) The joint of the ring beam is not welded, and it should be welded.
6. Lightning rod production and installation
(1) The welding place is not full, the solder treatment is not clean, the brush anti-rust paint should be welded in time, the drug skin is knocked clean, and the anti-rust paint is brushed.
(2) The needle body is bent, and the appropriateness of the installation exceeds the allowable deviation, and the needle body should be resalined and installed after meeting the requirements.
7. Grounding trunk line installation
(1) The flat steel is not straight and should be readjusted.
(2) The grounding terminal leakage pad spring pad should be completed in time.
(3) The weld joint has the phenomenon of clipping, biting, cracking, stomata and unscrapered treatment of the drug skin, etc., and should be repaired and changed according to the requirements of the specification.
8. Miscellaneous
(1) Leakage of brush anti-rust paint should be repainted in time.
(2) The protective distance between the single-house lightning rod and its grounding device and the entrance and exit of the road or building does not meet the regulations, and its distance should be greater than 3m, and when it is less than 3m, it should take pressure equalization measures or lay pebble or asphalt ground.
(3) When using the main rib as a lightning protection lead, in addition to the main rib section shall not be less than 90mm2, its welding method can be pressure submerged arc welding butt welding, etc.; mechanical methods can be cold extruded wire connection, etc., and the above joint can be used to do lightning protection lead down the line, but it is necessary to carry out hidden engineering inspection and acceptance.
6. Quality records
(1) Galvanized flat steel or round steel material certificate and product factory certificate.
(2) Lightning protection and grounding construction pre-inspection, self-inspection, hidden inspection records are complete.
(3) Design change negotiation record, completion drawing.
(4) Lightning protection grounding sub-project quality site inspection and evaluation records.
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