Chapter 1 General
Article 1 - To reduce and prevent the danger of lightning strikes, to protect the safety of life and property of the country and people, to standardize the detection of lightning protection facilities in the province and to ensure the quality of inspections, according to the "Meteorological Regulations of the Province" and the "Administrative Measures for Lightning Prevention and Mitigation of the Province". Formulate these rules.
Article 2 The inspection agencies at all levels of the province shall be based on the National Standard of the People's Republic of China "Standards for the establishment of juices for buildings" (hereinafter referred to as the "Specifications") and the current relevant technical specifications and standards, and shall strictly follow the "Quality Management Manual" formulated by the inspection organizations at all levels. 》Working.
Article 3 The "Detailed Rules" shall apply to the use of mine detection agencies at all levels in the province.
Chapter II Inspection Project
Article 4 Judgment of Lightning Protection Category for Buildings (including Structures, the Same below)
According to the importance of the building, the nature of the use, the possibility and consequences of the occurrence of a lightning accident, and the lightning protection requirements are divided into three categories. For the classification of lightning protection of various types of buildings, see "Lightning Protection Design Specifications for Buildings"
Article 5 Examination of Design Documents for Construction Drawings of Lightning Protection Devices of a Building
The design review office shall be responsible for the review of the lightning protection installation drawing design documents.
To examine whether there are measures to prevent direct lightning strikes and lightning wave intrusion in the lightning protection design of Class I, II and III newly constructed and constructed buildings. For the second type of lightning protection buildings of the first type and No. 2.0.3 of No. 2.0.3 of the “Specifications”, it is still necessary to examine whether or not lightning protection measures shall be taken.
Lightning protection equipment construction drawing design documents review sub-drawings and on-site review. Mainly in accordance with lightning protection category to check whether the lightning protection meets the requirements of the specification, whether the drawings are normative, and whether the design unit is qualified, the on-site inspection is mainly based on the review of whether the construction plan according to the design, and ultimately through the on-site testing to determine the performance of the facility. . After the completion of the review, the inspection station shall be notified to perform on-site tracking and inspection according to the results of the review.
Article 6 Detection of Lightning Protection Devices for Buildings.
1, the geometry of the building.
Characterize the structure and features of the building, and also provide the length, width, height, radius, etc. of the building for the determination or determination of the parameters of the lightning protection device. Due to the different buildings, this rule specifies the measurement of the geometric dimensions of the building as follows (see drawing).
(1) Measurement of the dimensions of the sky
Measure sky dimension according to "common sky shape measurement diagram"
(2) Height
Measure height of building according to "height measurement diagram".
(3) Measurement requirements for building geometry
A Unit: m, instrument: tape measure (length, width, height), accuracy 0.01m (high, accuracy 0.2m, range 0-70m). 0-50m, line-of-sight altimeter
B. The dimensions of the aeroplane are measured on the ground in the case of a reference design and measured on the surface of the sky when there is a special shape.
C The length and width of the ground shall be measured at a height of 1.2m from the ground. The tape shall be kept straight. When using a tape measure, it shall be kept vertical. When measuring the geometric dimension with a tape measure, two persons must take a reading. When the reading error of the two persons is less than ± 0.1 In m, only one measurement is made and recorded. When the error is greater than ±0.1m, the measurement should be repeated until the error is satisfied. When using the line-of-sight altimeter to measure the height, at least two gears are selected to measure the distance. The two measurement errors are less than ±0.2m. Otherwise, the measurement is repeated until the error is met.
(4) Judgment: There is no standard for the geometry of the building, and no judgment on whether it is qualified or not.
2, the type of lightning receptor
The types of lightning receptors include lightning rods, lightning protection strips, lightning protection nets, and lightning protection cables. According to the design drawings and the site's visual inspection, it is determined that the same type of building can use different types of air-termination devices. Therefore, the air-termination device only records and does not make judgments.
3, the effective height of the lightning receptor
The effective height of the flasher refers to the height of the receptor above the plane of the object to be protected.
(1) The effective height of the lightning rod = the height of the lightning rod - the height of the object to be protected.
(2) The height of the lightning rod and the height of the object to be protected shall be m. Measured with a line-of-sight altimeter, with an accuracy of 0.2m, the same target shall be selected for two ranges of distance measurement. The two measurement errors shall be less than ±0.2m, otherwise Measurement. The measuring person should keep the lightning rod and the object to be protected on the same plane.
(3) The effective height of the lightning conductor = the minimum height of the lightning conductor from the ground - the height of the object to be protected.
(4) The projection point of the lowest point of the lightning conductor is the lowest point of the two rods of the lightning conductor. According to the above method, the minimum point of the lightning conductor and the height of the object to be protected can be measured by the line-of-sight altimeter. Measurement methods and requirements are the same as before.
(5) The effective height of the lightning protection zone: The effective height of the lightning protection zone is the height of the lightning protection zone above the protected roof. For the lightning protection strips on flat roofs, the height regulations can only be between 0.1-0.3m. For the lightning protection strips laid on the daughter's wall, there is no standard for the height above the parapet walls.
(6) The height of the flat roof lightning protection zone is measured with a steel tape measure or a tape measure with an accuracy of 0.001m. The long edge is selected at one point every 10-15m, and the short edge is only measured at one point. The measurement error at each point should be less than ±0.005m. Otherwise retest. Parapet wall lightning strips do not measure height.
(7) Lightning rods, lightning conductors and non-planar lightning conductor heights are only used as the basic parameters for calculating the protection scope. They are not judged as qualified; the effective height of roof lightning protection strips for newly-built buildings must meet the design requirements, and the height of lightning protection strips for building inspections should be the same. There is no inconsistency between levels, otherwise it is judged as unqualified.
4、Aircraft Specifications
(1) The lightning rod should be made of round steel or welded steel pipe, and its specifications should meet the following requirements:
When the needle length is less than lm, the diameter of the round bar is ≥12mm and the diameter of the steel pipe is ≥20mm;
When the needle length is 1-2m, the diameter of round bar ≥ 16mm, the diameter of steel pipe ≥ 25mm;
Chimney on the top of the chimney, diameter of round bar ≥ 20mm, diameter of steel pipe ≥ 40mm.
(2) Materials and specifications of lightning protection nets and lightning protection strips
Lightning protection nets and lightning protection strips should be round steel or flat steel, and their specifications should meet the following requirements:
Round steel diameter ≥ 8mm Flat steel section ≥ 48mm2 Thickness ≥ 4mm.
(3) Lightning protection on top of chimney adopts round steel flat steel
Round steel diameter ≥ l2mm. Flat steel section ≥ lOOmm2 thickness ≥ 4mm.
(4) Measured with a vernier caliper, accuracy 0.02mm, lightning rod diameter should be made twice repeated measurement, the error is less than 0.1mm, otherwise re-measurement, lightning strip specifications measurement long side at least every 15-20m choose a point, short side at least selected One point of measurement, each measurement point should be repeated for two measurements, the error is less than 0.1mm.
(5) When the diameter of the lightning rod meets the requirements of its minimum specification, it is judged as qualified, otherwise it is judged as unqualified. When the lightning arrester does not meet the minimum specification when the edge-measurement result fails, it is judged to be unqualified
5, air receiver grid size:
(1) Specification requirements, one type ≤ 5m × 5m or 4m × 6m, two types ≤ 10m × 10m or ≤ 8m × 12m, three types ≤ 20m × 20m, or when the width does not exceed 20m, the surrounding surface is surrounded by circular lightning protection band.
(2) The measuring instrument is a tape measure with an accuracy of 0.01m and a measurement error of 0.05m.
(3) When measuring the same plane, two grid measurements that are not adjacent to each other should be selected. Each side measures two times and the error should be less than 0.05m. Otherwise, the measurement is repeated. For the third type of building, when the width of the same day is less than 20m, it is not necessary to install a grid, so it is only recorded as an "annular zone".
(4) When the mesh size on the same day meets the specified requirements, it is judged to be qualified, otherwise it is judged as unqualified; if it is less than 20m, if it is judged as "circular belt", it is judged as unqualified if it is not "ring belt".
6, pressure ring vertical distance
Third building width
(1) The first, second, and third types of lightning protection structures, when the height exceeds the radius of the rolling ball, the over-surfacing portion of the structure shall be laid along the perimeter of the wall of the building every 12m.
(2) Measure the belt spacing with a tape measure. The accuracy is 0.1m, the measurement error is ≤ 0.2m. Two non-adjacent wall measurements are selected. Each wall measurement is performed from top to bottom.
(3) When each zone of equalization pressure is less than 12m, the judgement is qualified. When any zone equalizing belt spacing is greater than 12m, the judgement is unqualified.
7, lead off the line
(1) Specifications
Round steel diameter ≥8mm
Downstream on the chimney
Flat steel section ≥ 48mm2 Flat steel thickness ≥ 4mm Round steel diameter ≥ l2mm Flat steel section ≥ l00mm2 Thickness ≥ 4mm Computer room down conductor Multi-core copper cross section≥35mm2
(2) When multiple subcontractors are used, breakout cards shall be installed between the lead-off distances of 0.3-1.8m. The distance between the downleads should be ≤12m (-), ≤18m (second-class), and ≤25m (three-category).
(3) Measuring instrument: vernier caliper, precision 0.02mm. The detection of lead-off line, its measurement allowable error is: round steel and steel pipe diameter ≤ 0.5mm flat steel thickness ≤ 0.1 mm
(4) Each lead from 0.1-0.5m away from the ground, optional - point measurement twice, when all primers to meet the requirements, determine the pass, otherwise unqualified.
(5) The lead-off line spacing is measured with a tape measure with an accuracy of 0.1m and a measurement error of ≤ 0.2m. Each measurement repeats twice and meets the requirements for determination. Otherwise, it fails.
8, highlight the roof of the metal objects are grounded
According to the “Code for the Design of Buildings for Lightning Protection” (GB50057-94), metal objects (such as water tanks, overhead pipes, etc.) that protrude from the roof should be grounded. The inspection methods are visual inspection and instrument measurement. According to the ground treatment or with roof lightning rods, belts, nets, etc., made a reliable welding, if made grounding treatment, determine the pass, did not press the ground treatment or connection is not good, to determine the unqualified.
9. Highlight whether roof metal is protected by lightning protection
The highlighting whether the roof non-gold flexure is protected by lightning protection mainly refers to whether the non-metallic roofing is installed with a flasher and grounded on it.
The inspection method is visual inspection. It is protected or equipped with a lightning arrester and grounded. It is judged as qualified, otherwise it is unqualified.
10, according to the measurement of ground resistance
(1) Technical requirements: Grounding resistance R ≤ 10Ω for each grounding device of Class I and II lightning protection buildings Ground resistance R ≤ 30Ω for each group.
(2) Measuring instruments: M4102, ZC-8, accuracy 0.2Ω.
(3) Measurement method: Operate according to the instruction manual of the instrument. Repeat the measurement twice with the measurement position of each group of grounding devices unchanged. The error should be less than ±0.2Ω. Otherwise, repeat the test. When observed data are close to the standard value, measurements should be made in at least two different directions that are not adjacent to each other.
(4) When the grounding resistance of each grounding device meets the technical requirements, it can be judged as qualified, otherwise it is judged as unqualified.
(5) Ground Resistance Measurement Wiring Method
When measuring the grounding resistance of a ground net, the wiring method usually used is generally a straight-line method, and the other method is a triangle method or an angle method.
1 electrode linear layout method:
The distance between the current pole and the edge of the grounding body is d13 = 4 - 5 times the diagonal length of the net, d12 = 50% - 60% d13. During the measurement, the voltage pole is moved three times along the connection line between the grounding body and the current pole. Each movement distance is 5% of d13, and the number of three measured differences is less than 5%. Then take the average of three times the ground resistance. In regions where soil resistivity is uniform, d13=2D and d12=1.2D.
2-electrode triangle method:
Generally take d13 = d12≥2D angle α≈30°
When measuring the microwave station ground network, electrode triangle arrangement must be adopted according to its industry standard. And d13=d12≥4--5D
Practice shows:
The grounding resistance value measured by the triangle method is less than the grounding resistance value measured by the straight line method. However, the grounding resistance obtained by the straight line method is more reliable. When measuring a large-scale ground network, a voltage and current meter method is applied and the electrodes are arranged in a triangle.
3 Requirements for measuring instruments
(1) Internal resistance:
Since the internal resistance of the meter directly affects the measurement reading, when the error due to the internal resistance of the meter is less than 2%, the internal resistance of the meter should be equal to or greater than 50 times the internal resistance of the voltage pole.
(2) Accuracy of meter:
The accuracy level of voltmeters, ammeters, current transformers, etc. used to measure the grounding resistance should not be lower than 0.5. (A total of 7 levels)
Conductor cross section:
The cross-section of the voltage-level lead during measurement should not be less than 1.0-1.5 square millimeters; the cross-sectional area of the current lead is determined by the magnitude of the current, preferably 5 A per square millimeter. The resistance of the conductor connected to the grounding body to be measured shall not be greater than 2-3% of the grounding resistance. It shall require the rust removal treatment at the lead of the grounding body and good contact so as to avoid measurement errors.
11, according to the specifications of the body
(1) Technical Requirements:
Artificial vertical grounding should use angle steel, steel pipe, or round steel. Artificial horizontal grounding body should use flat steel or round steel.
Its specifications are as follows:
Round steel diameter ≥ 10mm Flat steel section ≥ 100mm2 Thickness ≥ 4mm Thickness of angle steel ≥ 4mm Thickness of steel tube ≥ 3.5mm The manual vertical earthing body specification inspection generally uses the method of consulting the construction data and construction acceptance drawings to obtain data. The data is enclosed in parentheses when it is filled in, indicating that the data is not directly measured and used for reference only. However, if there are conditions that can be directly measured, it should be measured and recorded as it is. Measuring instruments, measuring methods, and determining principles are the same as those of the air receptor.
12. Inspection of whether the roof discharge pipes and interior design are grounded
(1) Technical requirements: The "Code" stipulates that the lightning protection structures of Types 1 and 2 Clause 3, 2, 1 and 4, 5, and 6 shall be used as lightning protection inductors for roof discharge pipe and indoor equipment.
(2) Measurement method: visually measure the roof discharge pipe and whether the indoor equipment is grounded. If it is grounded and the grounding resistance is less than 10Ω, it shall be judged as qualified, otherwise it shall be unqualified.
13, parallel pipe, line span spacing
(1) Technical requirements: When parallel metal pipe, line net distance