1. Buildinggrounding resistance requirements
    According to GB50057-94 (2000 version) "Building Lightning Protection Design Code" Chapter III, lightning protection measures for buildings; Section 2, lightning protection measures for lightning protection buildings of the first type, Article 3.2.1: The lightning protection grounding device should be shared with the electrical equipment grounding device, and its power frequency grounding resistance should not exceed 10Ω. Section 3, lightning protection measures for lightning protection buildings of the second type, Section 3.3.4: Grounding resistance of each down conductor is not less than 10Ω, anti-lightning grounding device and lightning protection, electrical equipment, information A common grounding device such as a system. Article 3.3.9: Lightning arrester, cable metal sheath, steel pipe and insulator iron feet, metal fittings, etc. should be grounded together, and the impact grounding resistance should not exceed 10Ω. Overhead and directly buried metal pipes shall be connected to the lightning protection grounding device at the entrance and exit of the building; when not connected, the overhead piping shall be grounded and its impact grounding resistance shall not exceed 10 Ω. For the buildings specified in paragraphs 4, 5 and 6 of Article 2.0.3 of this code, the metal pipes leading and leading the building shall be connected to the lightning protection grounding device at the entrance and exit; the overhead metal pipe shall be at a distance The building should be grounded once at about 25m, and its impact grounding resistance should not exceed 10Ω. Section 4, the third type of lightning protection measures for lightning protection buildings, Article 3.4.2: The impact grounding resistance of each down conductor should not be greater than 30Ω. Article 3.4.9: Lightning arrester, cable metal sheath and insulator iron feet, metal fittings, etc. should be grounded together, and the impact grounding resistance should not be greater than 30Ω.
 
2. Power system grounding resistance requirements
    According to JGJ/T16-92 "Electrical Design Code for Civil Buildings" Chapter 14 Grounding and Safety: According to the requirements of Article 14.7.5.3, when the grounding of the equipment room is shared with the lightning protection grounding system, the grounding resistance requirement is less than 1Ω. Therefore, the grounding of the monitoring equipment room and the communication equipment room should be shared with the lightning protection ground of the building, and the grounding resistance should be less than 1Ω.
    According to GB50089-98 "Safety Code for Civil Blasting Equipment Factory Design" Chapter 12: Electrical; Article 12.6.4: At the connection between cable and overhead line, lightning arrester should be installed. Arrester, cable metal sheath, steel pipe and insulator iron feet, fittings, etc. should be grounded together, and the impact grounding resistance should not be greater than 10Ω. Article 12.7.2: All kinds of outdoor overhead pipes for transporting dangerous materials should be grounded once every 20 to 25 meters, and the grounding resistance of each impact should not exceed 10 Ω. Article 12.7.3: Corresponding anti-static measures should be taken in hazardous areas. In the process of producing, processing or storing dangerous goods, metal equipment, metal pipes and conductive objects that may accumulate electrostatic charges shall be directly grounded, and the grounding resistance shall not exceed 100Ω. Article 12.7.4: The grounding of the low-voltage distribution line shall be TN-S or TN-C-S system, and the power line of the building shall be introduced. The neutral point shall be grounded repeatedly, and the grounding resistance shall not exceed 10Ω.
 
3. Petrochemical grounding resistance requirements
    According to GB50074-2002 "Code for Design of Petroleum Reservoirs" Chapter 14: Electrical Installations; Article 14.2.2: The spacing of the grounding point of steel tanks along the circumference of the tank should not exceed 30m, and the grounding resistance should not be greater than 10Ω. Article 14.2.3: The metal parts of the tank and tank of the earth-filled oil tank and the metal parts such as the breathing valve and the oil hole shall be electrically connected and grounded, and the grounding resistance shall not be greater than 10 Ω. Article 14.2.10: The grounding resistance of the metal pipe entering and leaving the hole shall not be greater than 20 Ω. Power and information lines should be buried in the hole using armored cables. The grounding resistance should not be greater than 20Ω. An overvoltage protector shall be installed at the junction of the cable and the overhead line. Overvoltage protector, cable sheath and porcelain iron feet should be electrically connected and grounded. The grounding resistance should not be greater than 10Ω. Article 14.2.13: The oil (oil and gas) pipeline entering the oil loading area shall be grounded at the entry point, and the grounding resistance shall not exceed 20 Ω. Article 14.2.16: The grounding resistance of the lightning rod (net, belt) should not be greater than 10Ω. Article 14.3.5: The electrified railway side of each group of insulated rail joints shall be provided with a set of grounding devices extending in the direction of the electrified railway. The grounding resistance shall not exceed 10 Ω. Article 14.3.6: Rails, oil pipelines, crane pipes, steel trestles, etc. of railway oil loading and unloading facilities shall be equipotentially connected and grounded. The distance between the two sets shall not exceed 20m, and the grounding resistance of each group shall not exceed 10Ω. . 14.3.15: The grounding resistance of the antistatic device should be less than 100Ω. Article 14.3.16: lightning protection grounding, anti-static grounding, working grounding of electrical equipment, protective grounding and grounding of information system in the oil depot, etc., the grounding device should be shared, and the grounding resistance should not exceed 4Ω.
    According to GB50156-2002 "Code for Design and Construction of Automobile Refueling Stations" Chapter 10: Electrical Installations; Article 10.2.2: Lightning protection grounding, anti-static grounding, working grounding of electrical equipment, protective earthing and grounding of information systems, etc. It is advisable to share the grounding device and its grounding resistance should not exceed 4Ω. Clause 10.2.3: When the liquefied gas cylinder is subjected to cathodic corrosion protection by sacrificial anode method, the grounding resistance of the sacrificial anode should not exceed 10 Ω. Article 10.3.1: The joint grounding device of anti-static and anti-inductive lightning shall be provided at the beginning, end and branch of the oil, liquefied petroleum gas and natural gas pipeline laid on the ground or trench, and the grounding resistance shall not exceed 30Ω. 10.3.4: The grounding resistance of the anti-static device should be less than 100Ω.
    According to GB50028-93 "Code for Town Gas Design", Article 6.10.2: The grounding resistance of the lightning protection grounding device should be less than 10Ω. Article 6.10.3: The grounding resistance of the electrostatic grounding body should be less than 100Ω. Article 7.2.31: When the building is outside the lightning protection zone, the lead of the discharge pipe shall be grounded, and the grounding resistance shall be less than 10Ω.
 
4. Computer system grounding resistance requirements
    According to the requirements of Chapter 4 of GB/T2887-2000 "General Rules for Electronic Computer Sites": Requirements for grounding in Section 4: Grounding resistance and mutual relationship requirements of Article 4.4.2, the working ground of the computer system DC, the grounding resistance should be determined according to the specific requirements of the computer system; AC work grounding, grounding resistance should not be greater than 4Ω; safety protection grounding, grounding resistance should not be greater than 4Ω; lightning grounding grounding resistance should not be greater than 10Ω. The relationship and connection between the various places should be determined by the requirements of different computer systems.
    According to GB50174-93 "Electronic Computer Room Design Specification" Chapter 6 Electrical Technology: Section 4 Grounding Requirements: Section 6.4.2, Section 6.4.3, AC working grounding, grounding resistance should not exceed 4Ω; safety protection grounding , the grounding resistance should not be greater than 4Ω; DC working grounding, grounding resistance should be determined according to the specific requirements of the computer system; lightning protection grounding should be carried out according to the current national standard "Building Lightning Protection Design Code". Article 6.4.3 requires AC grounding, safety protection grounding, DC working grounding, and lightning protection grounding. A set of grounding devices should be used, and the grounding resistance is determined by the minimum value.
 
5. Cable TV system grounding resistance requirements
    According to GB50198-94 "Civil Closed Circuit Surveillance Television System Engineering Technical Specification" Chapter 2: Section 2.5 Power Supply, Grounding and Safety Protection: Article 2.5.4 requires that when the system adopts a special grounding device, its grounding resistance shall not be greater than 4 Ω, and when integrated grounding, the grounding resistance shall not be greater than 1 Ω;
 
6. Mobile communication system grounding resistance requirements
    According to YD5068-98 "Design Specification for Lightning Protection and Grounding of Mobile Communication Base Stations", Chapter 5: Requirements for Grounding Resistance, 5.0.1: The grounding resistance of the grounding network of the mobile communication base station shall be less than 5 Ω, and the grounding resistance of the area with an annual thunderstorm day less than 20 days may be less than 10 Ω; 5.0.2: The grounding resistance of the protective earthing at the interface between the overhead power line and the power cable and the protective earthing of the power transformer (below 100KVA) shall be less than 10Ω. 5.0.3: The grounding resistance of the lightning protection line above the overhead power line and the lightning arrester installed on the high voltage line shall be less than 10Ω at the head end (ie, the inbound end) and less than 30Ω at the middle or end.
     According to Chapter 4 of YD2011-93 "Code for Design of Lightning Protection and Grounding for Microwave Stations": Grounding resistance requirements, 4.0.1: The power frequency grounding resistance of the ground station in the microwave should not exceed 10Ω; the power frequency grounding resistance of the grounding station of the microwave hub station should be no more than 5Ω. Its grounding resistance can be less than 10Ω; 5.0.2: The power frequency grounding resistance of the ground station in the passive station is 20~30Ω. 4.0.3: The grounding resistance of the protective earthing at the interface between the overhead power line and the power cable and the protective earthing of the power transformer (below 100KVA) shall be less than 10Ω. 4.0.4: The grounding resistance of the lightning protection line above the overhead power line and the lightning arrester installed on the high-voltage line shall be less than 10Ω at the head end (ie, the inlet end) and less than 30Ω at the middle or end.
   

上一篇：Methods for measuring insulation resistance

下一篇：ES3050 equipotential tester installation engineering typical