GOST standards for resistance of grounding devices of wired communication installations. Grounding for fixed installations of wired communications, radio relay stations, radio broadcasting nodes and antennas of collective television reception systems Terms used in
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GOST 464-79 Grounding for fixed installations of wired communications, radio relay stations, radio broadcasting nodes of wired broadcasting and antennas of collective television reception systems. Resistance standards.
GROUNDING CONNECTIONS FOR STATIONARY
WIRED COMMUNICATION INSTALLATIONS,
RADIO RELAY STATIONS,
RADIO BROADCASTING NODES
WIRED BROADCASTING AND ANTENNAS
COLLECTIVE RECEPTION SYSTEMS
TELEVISION
RESISTANCE STANDARDS
GOST 464-79
Moscow
STATE STANDARD OF THE USSR UNION
Date of introduction 01.01.80
This standard applies to station and linear structures of wired communication installations, radio relay stations, radio broadcasting nodes of wired broadcasting (WB), installations of selective railway communication and antennas of collective television reception systems (CPRT), for which stationary grounding devices are equipped, and establish standards for the resistance of grounding devices ensuring the normal operation of the structures and installations listed above, as well as the safety of operating personnel.
The standard does not apply to grounding devices that are provided in special-purpose equipment.
The terms used in this standard and their definitions are given in the Appendix.
1. GENERAL PROVISIONS
1.1. The following must be connected to the working-protective or protective grounding device using grounding wires using the shortest route:
one of the poles of the power supply installation;
neutral of transformers, output of a single-phase current source of a transformer substation or its own power plant that supplies equipment for communications enterprises, a radio relay station or a PV station;
metal parts of power, cabinet and switching equipment;
metal supporting equipotential surface of electronic telephone exchanges;
metal pipelines for water supply and central heating and other metal structures inside the building;
equipment and cable screens;
metal sheaths of cables, elements of protection circuits, lightning rods;
SKPT antennas subject to lightning protection in accordance with regulatory and technical documentation (hereinafter referred to as NTD).
The number of grounding wires and the procedure for connecting equipment and equipment to them are established in the technical documentation for equipment of a specific type.
(Changed edition, Amendment No. 2).
1.2. Telecommunications enterprises should be equipped with a protective grounding device if there are no connecting lines and remote power supply circuits for equipment that use the ground as an electrical circuit wire.
Requirements for protective grounding and grounding are in accordance with GOST 12.1.030.
(Changed edition, Amendment No. 1).
1.3. At communication enterprises, one working and protective grounding device should be equipped if the “minus” of the remote power supply current source is grounded (in this case, the remote power supply circuits can be connected according to the “wire-ground” circuit) or the “plus” of the current source is grounded, but there are no remote power supply circuits. power supply according to the wire-to-ground circuit. In this case, the connecting lines can use the ground as the wire of the electrical circuit. The circuit of the working and protective grounding device in the presence of remote power circuits must have two independent inputs into the building (before the grounding panel).
Enterprises should equip separate working and protective grounding devices if there are remote power circuits using a “wire-to-ground” circuit with grounding of the “plus” of the current source.
1.4. The neutral of transformers, the output of a single-phase current source of a transformer substation or its own power plant that supplies equipment for communications enterprises, a radio relay station or a PV station must be connected to a protective or operational-protective grounding device. In this case, the grounding device for the above enterprise and for the transformer substation must be common if the distance between the enterprise and the transformer substation is less than 100 m.
The resistance of the common grounding device must correspond to the resistance standards of grounding devices for each connected installation.
The resistance of the grounding device to which the neutrals of generators or transformers are connected or the output of a single-phase current source, with a soil resistivity of up to 100 Ohm m, should not be more than, Ohm:
2 - installations with voltage 660/380 V;
4 - installations with voltage 380/220 V;
8 - installations with voltage 220/127 V.
If the soil resistivity r is more than 100 Ohm m, it is allowed to increase the resistance value of the grounding device by r/100 times, but no more than ten times, and also no more than the values indicated in the table. Table 1-Table 3, Table 5 and in paragraphs. Clause 2.1.5, Clause 2.4.5, Clause 2.7.2.
1.3, 1.4. (Changed edition, Amendment No. 2).
1.4a. The resistance of a protective or operational-protective grounding device must be ensured taking into account the use of natural grounding conductors (metal pipes laid underground, metal structures, reinforcement of buildings and their concrete foundations, and others, with the exception of pipelines of flammable and explosive mixtures, sewerage, central heating and domestic water supply located outside the building in which the equipment of the communications company or the PV station is located).
(Introduced additionally, Amendment No. 2).
1.5. The design of artificial grounding devices or various circuits of a grounding device, the brand and cross-section of connecting conductors from the grounding device to the grounding panel, a list of equipment, equipment and protective elements connected to the grounding device, methods of connecting wires and their number, methods for measuring the resistance of grounding devices and soil resistivity installed in the technical documentation for a specific type of equipment.
(Changed edition, Amendment No. 2).
1.6. The distance between individual non-insulated parts of different grounding devices (between working, protective, measuring, etc.) in the area before entering the building should not be less than 20 m.
1.7. The resistance of the measuring grounding device should not be more than 100 Ohms in soils with a resistivity of up to 100 Ohm m and 200 Ohm in soils with a resistivity of more than 100 Ohm m.
1.8. The resistance of linear protective grounding devices for communication lines and wire hanging in areas of dangerous influence of power lines, electrified railways, as well as under the influence of radio stations and impulse influences (excluding lightning discharges), determined by calculation in accordance with the requirements of the NTD, should not exceed the values established by this standard.
(Changed edition, Amendment No. 2).
1.9. When operating grounding devices, their resistance should be checked periodically:
twice a year - in summer (during the period of greatest drying of the soil) and in winter (during the period of greatest freezing of the soil) - at long-distance, urban and rural telephone exchanges, telegraph stations, telegraph broadcasting, terminal and subscriber points;
once a year - in the summer (during the period of greatest drying out of the soil) - at radio relay stations, at stations and substations of radio broadcasting nodes;
once a year - before the start of the thunderstorm period (April - May) - in unattended reinforcement points (UPP) and regeneration points (RP) of long-distance, urban and rural communications; for containers of transmission system equipment (ICM-30, etc.);
once a year - before the start of a thunderstorm - on cable and overhead communication lines and radio broadcast networks, at cable supports and supports on which protective equipment is installed, at subscriber points of telephone and radio broadcast networks, at step-down transformers of payphone booths;
at least once a year (before the start of a thunderstorm) - for antennas of collective television reception systems.
Continue on to Resistance Standards. Resistance standards for grounding devices for long-distance telephone exchanges and terminal points of selective railway communications. Resistance standards of grounding devices for unattended amplification points of long-distance communication and intermediate points of selective railway communication. Resistance standards for grounding devices for telegraph stations and telegraph broadcast terminals and subscriber points. Resistance standards for grounding devices for city telephone exchanges and local railway communication stations
STATE STANDARD OF THE USSR UNION
GROUNDING CONNECTIONS FOR STATIONARY
WIRED COMMUNICATION INSTALLATIONS,
RADIO RELAY STATIONS,
RADIO BROADCASTING NODES
WIRED BROADCASTING AND ANTENNAS
COLLECTIVE RECEPTION SYSTEMS
TELEVISION
RESISTANCE STANDARDS
GOST 464-79
Moscow
STATE STANDARD OF THE USSR UNION
Date of introduction 01.01.80
This standard applies to station and linear structures of wired communication installations, radio relay stations, radio broadcasting nodes of wired broadcasting (WB), installations of selective railway communication and antennas of collective television reception systems (CPRT), for which stationary grounding devices are equipped, and establish standards for the resistance of grounding devices ensuring the normal operation of the structures and installations listed above, as well as the safety of operating personnel.
The standard does not apply to grounding devices that are provided in special-purpose equipment.
The terms used in this standard and their definitions are given in.
1. GENERAL PROVISIONS
1.1. The following must be connected to the working-protective or protective grounding device using grounding wires using the shortest route:
one of the poles of the power supply installation;
neutral of transformers, output of a single-phase current source of a transformer substation or its own power plant that supplies equipment for communications enterprises, a radio relay station or a PV station;
metal parts of power, cabinet and switching equipment;
metal supporting equipotential surface of electronic telephone exchanges;
metal pipelines for water supply and central heating and other metal structures inside the building;
equipment and cable screens;
metal sheaths of cables, elements of protection circuits, lightning rods;
SKPT antennas subject to lightning protection in accordance with regulatory and technical documentation (hereinafter - NTD).
The number of grounding wires and the procedure for connecting equipment and equipment to them are established in the technical documentation for equipment of a specific type.
(Changed edition, Amendment No. 2).
Requirements for protective grounding and grounding are in accordance with GOST 12.1.030.
(Changed edition, Amendment No. 1).
Enterprises should equip separate working and protective grounding devices if there are remote power circuits using a “wire-to-ground” circuit with grounding of the “plus” of the current source.
The resistance of the common grounding device must correspond to the resistance standards of grounding devices for each connected installation.
Resistance of the grounding device to which the neutrals of generators or transformers or the output of a single-phase current source are connected, with a soil resistivity of up to 100 Ohms× m should not be more, Ohm:
2 - installations with voltage 660/380 V;
4 - installations with voltage 380/220 V;
8 - installations with voltage 220/127 V.
With soil resistivityr more than 100 Ohm × m it is allowed to increase the resistance value of the grounding device byr/100 times, but no more than ten times, and also no more than the values indicated in the table. -, and in paragraphs. . . .
1.3, 1.4.
1.4a. The resistance of a protective or operational-protective grounding device must be ensured taking into account the use of natural grounding conductors (metal pipes laid underground, metal structures, reinforcement of buildings and their concrete foundations, and others, with the exception of pipelines of flammable and explosive mixtures, sewerage, central heating and domestic water supply located outside the building in which the equipment of the communications company or the PV station is located).
1.5. The design of artificial grounding devices or various circuits of a grounding device, the brand and cross-section of connecting conductors from the grounding device to the grounding panel, a list of equipment, equipment and protective elements connected to the grounding device, methods of connecting wires and their number, methods for measuring the resistance of grounding devices and soil resistivity installed in the technical documentation for a specific type of equipment.
(Changed edition, Amendment No. 2).
1.6. The distance between individual non-insulated parts of different grounding devices (between working, protective, measuring, etc.) in the area before entering the building should not be less than 20 m.
1.7. The resistance of the measuring grounding device should not be more than 100 Ohms in soils with a resistivity of up to 100 Ohms × m and 200 Ohm - in soils with a resistivity of more than 100 Ohm × m.
1.8. The resistance of linear protective grounding devices for communication lines and wire hanging in areas of dangerous influence of power lines, electrified railways, as well as under the influence of radio stations and impulse influences (excluding lightning discharges), determined by calculation in accordance with the requirements of the NTD, should not exceed the values established by this standard.
(Changed edition, Amendment No. 2).
1.9. When operating grounding devices, their resistance should be checked periodically:
twice a year - in summer (during the period of greatest drying of the soil) and in winter (during the period of greatest freezing of the soil) - at long-distance, urban and rural telephone exchanges, telegraph stations, telegraph broadcasting, terminal and subscriber points;
once a year - in the summer (during the period of greatest drying out of the soil) - at radio relay stations, at stations and substations of radio broadcasting nodes;
once a year - before the start of the thunderstorm period (April - May) - in unattended reinforcement points (UPP) and regeneration points (RP) of long-distance, urban and rural communications; for containers of transmission system equipment (ICM-30, etc.);
once a year - before the start of a thunderstorm - on cable and overhead communication lines and radio broadcast networks, at cable supports and supports on which protective equipment is installed, at subscriber points of telephone and radio broadcast networks, at step-down transformers of payphone booths;
at least once a year (before the start of a thunderstorm) - for antennas of collective television reception systems.
2. RESISTANCE STANDARDS
2.1. Resistance standards for grounding devices for long-distance telephone exchanges and terminal points of selective railway communications
2.1.1. Intercity telephone exchanges (MTS), terminal points of selective railway communications, line equipment shops (LAS) and intermediate amplification points with power supply installations must be equipped with a protective or operational-protective grounding device and two measuring grounding devices. When equipping working and protective grounding devices in accordance with clause, one measuring grounding device is installed, which must be connected in parallel to the protective grounding device.
In operating condition, measuring grounding devices must be connected on the grounding panel parallel to the protective or operational-protective grounding devices.
Up to 50
From 51 to 200
From 201 to 500
From 501 to 1000
St. 1000
Resistance of the working or working-protective grounding device, Ohm, no more
10,0
(Changed edition, Amendment No. 2).
The resistance of the working and protective grounding device, depending on the number of single-wire telegraph circuits introduced into the station (see GOST 5238, drawing 26 -31), should be no more than the values indicated in the table. .
Table 3
2.4. Resistance standards for grounding devices for city telephone exchanges and local railway communication stations
In operating condition, all three grounding devices must be connected in parallel on the grounding panel and are disconnected only to measure the resistance of the protective or operational-protective grounding device.
Table 5
Note: In cases where the connecting lines at the station are equipped with inductive and battery (using the ground as a current conductor) sets of the RSL type, the resistance value of the working and protective grounding is selected depending on the number of battery (polar) sets of the RSL type.
2.4.4. Maintenance-free amplifier and regeneration points powered remotely using the “wire-to-wire” and “wire-to-ground” circuits must be equipped with one protective grounding device, the resistance value of which must correspond to that given in paragraph .
2.5.2. Telephone exchanges with a capacity of up to 3000 numbers can be equipped with one protective or operational-protective grounding device, and temporary grounding devices can be used as measuring grounding devices.
(Changed edition, Amendment No. 2).
2.5.3. For compaction equipment of rural automatic telephone exchanges and radio telephone exchanges in the case of using the NUP “wire-to-wire” power supply system, one integrated protective grounding device should be used. In this case, unattended amplification points must be equipped with protective grounding devices with a resistance not exceeding the values specified in paragraphs. And .
2.5.4. Maintenance-free amplification points powered remotely using a wire-to-ground circuit should be equipped with two separate grounding devices: a working one and a line-protective one. The resistance of working and linear protective grounding devices should be no more than the values specified in paragraphs. And .
2.6. Grounding resistance standards for telephone exchanges with a local battery (MB)
2.6.1. Telephone exchanges of the MB system operating on two-wire circuits must be equipped with three separate grounding devices - a protective one and two measuring ones. In operation, these three grounding devices must be connected in parallel on the grounding panel. When the station capacity is up to 200 numbers, it is allowed not to equip stationary measuring grounding devices, and when measuring the protective grounding device, use temporary grounding devices.
2.6.2. The resistance of the protective grounding device of MB stations operating on two-wire circuits should be no more than the values indicated in table. .
2.7. Resistance standards for grounding devices for stations and PV
2.7.1. Stations and PV should be equipped with one protective or operational-protective grounding device. For control measurements of the resistance of the protective and working-protective grounding device, it is allowed to equip two stationary measuring grounding connections or use temporary grounding devices.
2.7-2.7.2.(Changed edition, Amendment No. 2).
2.7.3. PV stations and transformer substations feeding them, geographically close to one another (item), should be equipped with a common protective or operational-protective grounding device with a resistance of no more than the values specified in item.
(Introduced additionally, Amendment No. 2).
2.8. Resistance standards of grounding devices for combined installations of wired communication and PV
(Changed edition, Amendment No. 2).
2.8.1. Stationary installations of wired communications for various purposes, located in the same or adjacent buildings and powered by one transformer substation: intercity, city, railway selective communications and others, as well as stations and substations of radio broadcasting nodes, should be equipped with one common protective or operational-protective grounding device . In this case, the resistance of the connecting wires from the grounding device should be taken into account.
2.8.2. The resistance value of the common grounding device must comply with the standards for each connected installation.
2.8.3. It is not allowed to combine a common protective grounding device with a working one in unattended amplification points powered remotely by direct current.
2.9. Resistance standards for protective grounding devices for long-distance communication lines
2.9.1. Resistance values of grounding devices for:
cascade protection spark gaps of types IR-7, IR-10, IR-15 and IR-20;
spark gaps IR-0.2 or IR-0.3 - when installed on supports adjacent to the cable support or station;
spark gaps installed on overhead line wires to protect underground communication cables from lightning strikes;
lightning rods installed on overhead line supports;
rope and metal sheaths of cables suspended on overhead line supports should be no more than the values specified in table. .
Table 6
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2.9.4. The resistance of linear protective grounding devices for metal cable sheaths, protective wires (cables) or busbars laid in the ground when protecting the cable from lightning strikes should be no more than the values specified in table. . Table 8
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STATE STANDARD OF THE UNION OF GROUNDING FOR STATIONARY
WIRED COMMUNICATION INSTALLATIONS,
RADIO RELAY STATIONS,
RADIO BROADCASTING NODES
WIRED BROADCASTING AND ANTENNAS
COLLECTIVE RECEPTION SYSTEMS
TELEVISION
RESISTANCE STANDARDS
Moscow
STATE STANDARD OF THE USSR UNION
Date of introduction 01.01.80
This standard applies to station and linear structures of wired communication installations, radio relay stations, radio broadcasting nodes of wired broadcasting (WB), installations of selective railway communication and antennas of collective television reception systems (CPRT), for which stationary grounding devices are equipped, and establish standards for the resistance of grounding devices ensuring the normal operation of the structures and installations listed above, as well as the safety of operating personnel. The standard does not apply to grounding devices that are provided in special-purpose equipment. The terms used in this standard and their definitions are given in the appendix.
1. GENERAL PROVISIONS
1.1. The following must be connected to the working-protective or protective grounding device using grounding wires using the shortest route: one of the poles of the power supply installation; neutral of transformers, output of a single-phase current source of a transformer substation or its own power plant that supplies equipment for communications enterprises, a radio relay station or a PV station; metal parts of power, cabinet and switching equipment; metal supporting equipotential surface of electronic telephone exchanges; metal pipelines for water supply and central heating and other metal structures inside the building; equipment and cable screens; metal sheaths of cables, elements of protection circuits, lightning rods; SKPT antennas subject to lightning protection in accordance with regulatory and technical documentation (hereinafter - NTD). The number of grounding wires and the procedure for connecting equipment and equipment to them are established in the technical documentation for equipment of a specific type. (Changed edition, Amendment No. 2). 1.2. Telecommunications enterprises should be equipped with a protective grounding device if there are no connecting lines and remote power supply circuits for equipment that use the ground as an electrical circuit wire. Requirements for protective grounding and grounding are in accordance with GOST 12.1.030. (Changed edition, Amendment No. 1). 1.3. At communication enterprises, one working and protective grounding device should be equipped if the “minus” of the remote power supply current source is grounded (in this case, the remote power supply circuits can be connected according to the “wire-ground” circuit) or the “plus” of the current source is grounded, but there are no remote power supply circuits. power supply according to the wire-to-ground circuit. In this case, the connecting lines can use the ground as the wire of the electrical circuit. The circuit of the working and protective grounding device in the presence of remote power circuits must have two independent inputs into the building (before the grounding panel). Enterprises should equip separate working and protective grounding devices if there are remote power circuits using a “wire-to-ground” circuit with grounding of the “plus” of the current source. 1.4. The neutral of transformers, the output of a single-phase current source of a transformer substation or its own power plant that supplies equipment for communications enterprises, a radio relay station or a PV station must be connected to a protective or operational-protective grounding device. In this case, the grounding device for the above enterprise and for the transformer substation must be common if the distance between the enterprise and the transformer substation is less than 100 m. The resistance of the common grounding device must correspond to the resistance standards of grounding devices for each connected installation. The resistance of the grounding device to which the neutrals of generators or transformers are connected or the output of a single-phase current source, with a soil resistivity of up to 100 Ohm × m, should not be more than, Ohm: 2 - installations with a voltage of 660/380 V; 4 - installations with a voltage of 380/220 V; 8 - installations with a voltage of 220/127 V. If the soil resistivity r is more than 100 Ohm × m, it is allowed to increase the resistance value of the grounding device by r /100 times, but not more than ten times, and also no more than the values indicated in the table. 1- 3, 5 and in paragraphs. 2.1.5, 2.4.5, 2.7.2. 1.3, 1.4. 1.4a. The resistance of a protective or operational-protective grounding device must be ensured taking into account the use of natural grounding conductors (metal pipes laid underground, metal structures, reinforcement of buildings and their concrete foundations, and others, with the exception of pipelines of flammable and explosive mixtures, sewerage, central heating and domestic water supply located outside the building in which the equipment of the communications company or the PV station is located). 1.5. The design of artificial grounding devices or various circuits of a grounding device, the brand and cross-section of connecting conductors from the grounding device to the grounding panel, a list of equipment, equipment and protective elements connected to the grounding device, methods of connecting wires and their number, methods for measuring the resistance of grounding devices and soil resistivity installed in the technical documentation for a specific type of equipment. (Changed edition, Amendment No. 2). 1.6. The distance between individual non-insulated parts of different grounding devices (between working, protective, measuring, etc.) in the area before entering the building should not be less than 20 m.1.7. The resistance of the measuring grounding device should not be more than 100 Ohms in soils with a resistivity of up to 100 Ohm ×m and 200 Ohms in soils with a resistivity of more than 100 Ohm ×m. 1.8. The resistance of linear protective grounding devices for communication lines and wire hanging in areas of dangerous influence of power lines, electrified railways, as well as under the influence of radio stations and impulse influences (excluding lightning discharges), determined by calculation in accordance with the requirements of the NTD, should not exceed the values established by this standard. (Changed edition, Amendment No. 2). 1.9. When operating grounding devices, their resistance should be checked at intervals: twice a year - in summer (during the period of greatest drying out of the soil) and in winter (during the period of greatest freezing of the soil) - at long-distance, city and rural telephone exchanges, telegraph stations, telegraph broadcasting, terminal and subscriber points; once a year - in the summer (during the period of greatest drying out of the soil) - at radio relay stations, at stations and substations of radio broadcasting nodes; once a year - before the start of the thunderstorm period (April - May) - in unattended reinforcement points (UPP) and regeneration points (RP) of long-distance, urban and rural communications; for containers of transmission system equipment (ICM-30, etc.); once a year - before the start of a thunderstorm - on cable and overhead communication lines and radio broadcast networks, at cable supports and supports on which protective equipment is installed, at telephone and radio broadcasting networks, at step-down transformers of payphone booths; at least once a year (before the start of a thunderstorm) - for antennas of collective television reception systems.2. RESISTANCE STANDARDS
2.1. Resistance standards for grounding devices for long-distance telephone exchanges and terminal points of selective railway communications 2.1.1. Intercity telephone exchanges (MTS), terminal points of selective railway communications, line equipment shops (LAS) and intermediate amplification points with power supply installations must be equipped with a protective or operational-protective grounding device and two measuring grounding devices. When equipping working and protective grounding devices in accordance with clause 1.3, one measuring grounding device is installed, which must be connected in parallel to the protective grounding device. In operating condition, measuring grounding devices must be connected on the grounding panel parallel to the protective or operational-protective grounding devices. 2.1.2. Resistance of protective grounding devices of MTS, linear hardware shops and intermediate amplification points, as well as terminal points of selective railway communication with power supply installations that do not use the ground as a current conductor in circuits of connecting lines or remote power supply of unattended amplification and regeneration points using the “wire- earth”, should be no more than the values specified in clause 1.4. 2.1.3. The resistance of protective grounding devices at intermediate points that do not have power supply installations should be no more than 10 Ohm for soils with a resistivity of up to 100 Ohm × m and no more than 30 Ohm for soils with a resistivity of more than 100 Ohm × m. 2.1.4. The resistance of working or working-protective grounding devices of MTS, using the ground as one of the wires of connecting lines of any type (custom, service from MTS and ATS, transit service lines, etc.), or in remote power supply (DP) circuits should be no more values indicated in table. 1, and operational and protective grounding devices must also comply with the requirements of clause 1.4.Table 1
(Changed edition, Amendment No. 2). 2.1.5. Resistance of working or working-protective grounding devices of linear equipment shops, support points; serviced amplifier points feeding remotely unattended or regeneration points using the “wire-to-ground” circuit must be determined based on the voltage drop on the grounding device from the remote supply current of no more than 12 V. However, the resistance of working or operational-protective grounding devices should not be more than the values specified in clause 1.4. 2.1.6. Serviced amplification points of underwater cable lines that remotely feed underwater amplifiers using the wire-to-ground circuit must be equipped with two separate working grounding devices (main and backup), which in working order must be connected to the grounding panel. The resistance of the main working grounding device should be no more than 5 Ohms and the backup one - no more than 10 Ohms. (Introduced additionally, Amendment No. 2). 2.2. Resistance standards of grounding devices for unattended amplification points of long-distance communication and intermediate points of selective railway communication 2.2.1. Unattended amplification points (NUA), fed remotely using a wire-to-ground circuit, in which the remote power supply circuit ends, must be equipped with three separate grounding devices - working, protective and line-protective. Magnesium protectors used to protect metal NUP tanks from soil corrosion may be used as a protective grounding device. In cases where it is not necessary to protect metal tanks of the LUP from soil corrosion, as well as when using non-metallic bodies, the LUP must be equipped with a working and integrated protective grounding device. 2.2.2. Unattended amplification points (NUP) and regeneration points (RP), fed remotely according to the “wire-to-wire” circuit, as well as UUP, powered according to the “wire-to-ground” circuit, in which the remote power supply circuit does not end, must be equipped with two separate grounding connections. devices - protective and linear protective. As grounding conductors for a protective grounding device, it is allowed to use magnesium protectors used to protect metal tanks of the LUP or RP from soil corrosion. In cases where protection of metal tanks of the LUP or RP from corrosion is not required, as well as when using non-metallic bodies of the LUP or RP, it must be equipped with a combined protective grounding device. 2.2.3. The resistance of the working grounding device for LUPs powered by a wire-to-ground circuit must be no more than 10 Ohms for soils with a resistivity of up to 100 Ohms × m and no more than 30 Ohms for soils with a resistivity of more than 100 Ohms × m. When In this case, the voltage drop from remote power currents across the resistance of the grounding device should be no more than 12 V for soils with a resistivity of up to 100 Ohm × m and no more than 36 V for soils with a resistivity of more than 100 Ohm × m. 2.2.4. The resistance of protective grounding devices for LUP or RP, powered by a “wire-to-ground” and “wire-to-wire” circuit, should be no more than 10 Ohms for soils with a resistivity of up to 100 Ohm × m and no more than 30 Ohms for soils with a specific resistance resistance more than 100 Ohm × m. 2.2.5. The resistance of linear protective grounding devices for cable sheaths equipped at the NUP or RP, when protecting cables from lightning strikes, should be no more than, Ohm: 10 - for soils with a resistivity of up to 100 Ohm × m inclusive. ; 20 - for soils with a resistivity of St. 100 to 500 Ohm × m incl.; 30 - for soils with a resistivity of St. 500 to 1000 Ohm × m incl.; 50 - for soils with a resistivity of St. 1000 Ohm × m. (Changed edition, Amendment No. 2). 2.2.6. Intermediate points of selective railway communication must be equipped with one protective grounding device, the resistance of which must not exceed the values specified in Table. 2.table 2
2.3. Resistance standards for grounding devices for telegraph stations and telegraph broadcast terminals and subscriber points. 2.3.1. Telegraph stations, broadcasting, terminal and subscriber points operating on two-wire circuits, located in a separate building (not combined with MTS, automatic telephone exchanges and other enterprises) and not using “ground” as an electrical circuit wire, must be equipped with a protective and two measuring grounding devices. In operating condition, all grounding devices must be connected in parallel on the grounding panel. Telegraph stations, broadcast terminals and subscriber points combined with other enterprises (MTS, ATS) must include grounding wires to a common protective grounding device. For telegraph stations where up to five telegraph devices are installed, it is allowed to use temporary measuring grounding devices. 2.3.2. The resistance of the protective grounding device of telegraph stations that have power supply installations should not exceed the values specified in clause 1.4. Broadcasting, terminal and subscriber points that do not have power supply installations must be equipped with a protective grounding device with a resistance of no more than 10 Ohms at a specific resistance soil up to 100 Ohm ×m and 20 Ohm - for soils with a resistivity of more than 100 Ohm ×m. 2.3.3. Telegraph stations and telegraph broadcasting points operating on single-wire circuits must be equipped with a working-protective and two measuring grounding devices. For telegraph stations where up to five telegraph devices are installed, it is allowed to use temporary measuring grounding devices. The resistance of the working and protective grounding device, depending on the number of single-wire telegraph circuits introduced into the station (see GOST 5238, drawing 26-31), should be no more than the values indicated in the table. 3.Table 3
2.4. Resistance standards for grounding devices for city telephone exchanges and local railway communication stations 2.4.1. Telephone exchanges with a central battery (automatic telephone exchanges and manual telephone exchanges - RTS) must be equipped with three separate grounding devices - a protective or operational-protective one and two measuring ones. In operating condition, all three grounding devices must be connected in parallel on the grounding panel and are disconnected only to measure the resistance of the protective or operational-protective grounding device. 2.4.2. Telephone exchanges that have connecting lines and do not use the ground as a current conductor (for example, connecting lines equipped with inductive sets of the RSL type) should be equipped with protective grounding devices (clause 1.2), the resistance of which should not exceed the values specified in clause. 1.4. Telephone exchanges that do not have supply transformer substations receiving power from electrical networks with a voltage of 380/220/127 V must be equipped with a protective grounding device with a resistance not exceeding the values specified in table. 4.Table 4
(Changed edition, Amendment No. 2). 2.4.3. Telephone exchanges that have connecting lines using the ground as current conductors (according to clause 1.3) must be equipped with operational and protective grounding devices, the resistance of which should not exceed the values indicated in the table. 5 .Table 5
Note. In cases where the connecting lines at the station are equipped with inductive and battery (using the ground as a current conductor) sets of the RSL type, the resistance value of the working and protective grounding is selected depending on the number of battery (polar) sets of the RSL type. 2.4.4. Unattended booster and regeneration points powered remotely using the “wire-to-wire” and “wire-to-ground” circuits must be equipped with one protective grounding device, the resistance value of which must correspond to that given in clause 2.2.4. 2.4.5. The resistance of the protective or operational-protective grounding device of electronic telephone exchanges must be no more than 4 Ohms, and also comply with the requirements of paragraphs. 2.4.2 and 2.4.3. (Introduced additionally, Amendment No. 2). 2.5. Resistance standards for grounding devices of rural telephone exchanges (RTS) 2.5.1. Rural telephone exchanges with a central battery (RTS and ATS) must be equipped with three separate grounding devices in accordance with paragraphs. 2.4.1- 2.4.3.2.5.2. Telephone exchanges with a capacity of up to 3000 numbers can be equipped with one protective or operational-protective grounding device, and temporary grounding devices can be used as measuring grounding devices. (Changed edition, Amendment No. 2). 2.5.3. For compaction equipment of rural automatic telephone exchanges and radio telephone exchanges in the case of using the NUP “wire-to-wire” power supply system, one integrated protective grounding device should be used. In this case, unattended amplification points must be equipped with protective grounding devices with a resistance not exceeding the values specified in paragraphs. 2.1.2 and 2.1.3. 2.5.4. Maintenance-free amplification points powered remotely using a wire-to-ground circuit should be equipped with two separate grounding devices: a working one and a line-protective one. The resistance of working and linear protective grounding devices should be no more than the values specified in paragraphs. 2.2.3 and 2.2.5. 2.6. Grounding resistance standards for telephone exchanges with a local battery (MB) 2.6.1. Telephone exchanges of the MB system operating on two-wire circuits must be equipped with three separate grounding devices - a protective one and two measuring ones. In operation, these three grounding devices must be connected in parallel on the grounding panel. When the station capacity is up to 200 numbers, it is allowed not to equip stationary measuring grounding devices, and when measuring the protective grounding device, use temporary grounding devices. 2.6.2. The resistance of the protective grounding device of MB stations operating on two-wire circuits should be no more than the values indicated in table. 2. 2.7. Resistance standards for grounding devices for stations and substations 2.7.1. Stations and PV should be equipped with one protective or operational-protective grounding device. For control measurements of the resistance of the protective and working-protective grounding device, it is allowed to equip two stationary measuring grounding connections or use temporary grounding devices. 2.7.2. The resistance of the protective or operational-protective grounding device for PV stations should be no more than 10 Ohms. 2.7-2.7.2. (Changed edition, Amendment No. 2). 2.7.3. PV stations and transformer substations feeding them, geographically close to one another (clause 1.4), should be equipped with a common protective or operational-protective grounding device with a resistance of no more than the values specified in clause 1.4. (Introduced additionally, Amendment No. 2). 2.8. Resistance standards of grounding devices for combined installations of wired communication and PV (Changed edition, Amendment No. 2). 2.8.1. Stationary installations of wired communications for various purposes, located in the same or adjacent buildings and powered by one transformer substation: intercity, city, railway selective communications and others, as well as stations and substations of radio broadcasting nodes, should be equipped with one common protective or operational-protective grounding device . In this case, the resistance of the connecting wires from the grounding device should be taken into account. 2.8.2. The resistance value of the common grounding device must comply with the standards for each connected installation. 2.8.3. It is not allowed to combine a common protective grounding device with a working one in unattended amplification points powered remotely by direct current. 2.9. Resistance standards for protective grounding devices for long-distance communication lines 2.9.1. Resistance values of grounding devices for: cascade protection spark gaps of types IR-7, IR-10, IR-15 and IR-20; spark gaps IR-0.2 or IR-0.3 - when installed on supports adjacent to the cable support or station; spark gaps installed on overhead line wires to protect underground communication cables from lightning strikes; lightning rods installed on overhead line supports; rope and metal sheaths of cables suspended on overhead line supports should be no more than the values specified in table. 6.Table 6
(Changed edition, Amendment No. 2). 2.9.2. The resistance of protective grounding devices for input, cable and other supports of intercity communication lines and selective railway communications, on which, in accordance with the requirements of GOST 5238, it is required to turn on spark gaps of types IR-0.2 and IR-0.3 or gas-filled gaps, must not be more than the values indicated in the table. 7.Table 7
2.9.3. The resistance of protective grounding devices for arresters of type IR-0.3, included to protect the blocking coils in the third circuits (see GOST 5238, Fig. 9), must be no more than the values indicated in the table. 6. 2.9.4. The resistance of linear protective grounding devices for metal cable sheaths, protective wires (cables) or busbars laid in the ground when protecting the cable from lightning strikes should be no more than the values specified in table. 8.Table 8
Note. The number of linear protective grounding devices, their placement on cable lines and the method of connecting metal shells, cables and cable screens are established in the regulatory and technical documentation. 2.10. Resistance standards of protective grounding devices for lines of urban and rural telephone networks and local railway communication networks 2.10.1. Resistance of grounding devices for spark gaps of types IR-0.2; IR-0.3; IR-7; IR-10 and IR-15, connected according to diagrams. 19, 22-24 GOST 5238, should be no more than the values specified in table. 6.2.10.2. Resistance of grounding devices for gas-filled arresters of types R-84 and R-35 installed in cable boxes at the junctions of overhead lines of GTS, STS and railway communication networks with cable lines (see GOST 5238, drawings 15-17; 21a), and also for installation points of blockers (see GOST 5238, Fig. 24), there should be no more than the values specified in the table. 9.Table 9
(Changed edition, Amendment No. 2). 2.10.3. The resistance of grounding devices for subscriber points (see GOST 5238, drawings 16, 17, 21), for step-down transformers of payphone booths and lightning rods installed on overhead line supports should be no more than the values specified in table. 10 .Table 10
2.10.4. The resistance of grounding devices for the metal sheath of the cable, the screen of the cable with non-metallic sheaths when suspended on the supports of pole and rack lines, the rope used when suspending cables, as well as for the body of telephone distribution cabinets of the ShR or ShRP type, in which the cables are included, must not be more than the values indicated in the table. 6.2.10.5. The resistance of linear protective grounding devices when protecting GTS and STS cables laid in the ground from lightning strikes, as well as for the housing of telephone distribution cabinets of the ShR and ShRP types in which the cables are included, should be no more than the values specified in Table. 8. 2.11. Resistance standards for protective grounding devices on PV lines 2.10.4, 2.10.5, 2.11. (Changed edition, Amendment No. 2). 2.11.1. Resistance of linear protective grounding devices for spark gaps of types IR-0.5 and IR-7.0 (see GOST 14857, drawings 1, 2), as well as for spark gaps of types IR-0.3 and IR-7.0 (see GOST 14857, drawings 3, 5, 6) should be no more than the values indicated in the table. 6. 2.11.2. The resistance of linear protective grounding devices for grounding the metal sheath and screen of cables laid in cable ducts and collectors (at the beginning and end of the cable) must be no more than the values indicated in table. 8. 2.11.3. The resistance of linear protective grounding devices for lightning rods installed on the supports of overhead power lines must be no more than the values specified in table. 10. (Changed edition, Amendment No. 2). 2.12. Resistance standards for grounding devices for radio relay stations 2.12.1. Radio relay stations, including those with compaction equipment, must be equipped with one protective grounding device. To monitor the resistance of the protective grounding device, it is allowed to equip two stationary measuring grounding devices or use temporary grounding devices. In operating condition, protective and measuring stationary grounding devices must be connected in parallel on the grounding board. 2.12.2. The resistance of the protective grounding device must be no more than the values specified in clause 1.4. 2.13. Resistance standards for grounding devices for antennas of the collective television reception system 2.13.1. To protect SKIT antennas from dangerous voltages and currents arising from lightning discharges, a protective grounding device must be equipped. To monitor the resistance of the protective grounding device, it is allowed to use temporary measuring grounding devices. 2.13.2. It is allowed to connect lightning rods from two or more SKPT antennas located on the same building to one grounding device. 2.13.3. The design of the grounding device, as well as the lightning rod connecting the SKPT antenna to the grounding device, and the method of connecting them are established in the regulatory and technical documentation. 2.13.4. The resistance of the grounding device for SKPT antennas should be no more than the values indicated in the table. 6. 2.13.5. If there is a grounding device for the building on which the SKPT antennas are located (when protecting buildings from lightning strikes or to protect telephone communication and radio broadcasting equipment), it is allowed to connect lightning rods from the SKPT antennas to the existing grounding device. The resistance of the grounding device must be no more than the values indicated in the table. 6.APPLICATION
Information
TERMS USED IN THIS STANDARD AND THEIR DEFINITIONS
|
Definition |
|
| Grounding for wired communication installations, radio relay stations, MF radio broadcasting units, etc. | Intentional electrical connection of plant equipment or apparatus to a grounding device |
| Ground electrode | A metal conductor or group of conductors of any shape (pipe, angle, wire, etc.) in direct contact with the ground (soil) |
| Grounding conductor | Metal conductor connecting the grounded equipment or equipment to the ground electrode |
| Grounding device | A set of grounding conductors and grounding conductors |
| Resistance of the grounding device or resistance to current spreading | The total electrical resistance of the grounding conductors and the ground electrode relative to the ground, expressed in ohms. The resistance of the grounding conductor relative to the ground is defined as the ratio of the voltage of the grounding conductor relative to the ground to the current passing through the grounding conductor into the ground |
| Soil resistivity | Electrical resistance exerted by soil with a volume of 1 m 3 when current passes from one side of the soil to the opposite. The soil resistivity, denoted by r and expressed in ohms per meter, should be measured taking into account seasonal variations, taking the most unfavorable value as the calculated value |
| Working grounding device | A device intended for connecting wired communication equipment and radio devices (PV substations, radio relay stations) to the ground for the purpose of using the ground as one of the wires of the electrical circuit |
| Protective grounding device | A device designed for connecting to the ground the neutral wires of the windings of power transformer substations, lightning rods, arresters, equipment screens and in-station installation wires, metal sheaths and armored covers of cables, metal tanks, unattended amplification points (UPP), metal parts of power equipment of wired communication installations and stations PV, installations for maintaining cables under pressure and other equipment that are not normally energized, but may become energized if the insulation of live wires is damaged. Protective grounding devices ensure that the potential of metal parts of equipment is equalized with the ground potential and thereby protect operating personnel and equipment from the occurrence of dangerous potential differences with respect to the ground. |
| Linear protective grounding device | A device that provides grounding of metal cable sheaths and armored covers along the cable route and at stations (NSP) where cable lines are suitable, as well as on overhead lines for grounding lightning rods, cables and metal cable sheaths, etc. In some cases, it is possible to combine protective and linear protective grounding devices. Such a grounding device is called a combined protective |
| Measuring grounding device | An auxiliary device designed for control measurements of the resistance of working, protective and working-protective grounding devices. The resistance of the working and protective grounding devices should be measured, as a rule, from the grounding panel at the station, including the grounding conductor towards the grounding conductor. The resistance of grounding devices on overhead and cable lines is measured directly on the line |
| Working and protective grounding device | A device that serves simultaneously as both a working and a protective grounding device. The resistance of the working and protective grounding device must be no more than the minimum value provided for the working and protective grounding devices. |
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR Ministry of CommunicationsDEVELOPERS:A.K. Slanov(topic leader); V.V. Zakharov2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated January 29, 1979 No. 3043. The standard is unified with BDS 4722-704. Inspection frequency - 5 years5. INSTEAD GOST 464-686. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS 7. The validity period was lifted according to Protocol No. 4-93 of the Interstate Council for Standardization, Metrology and Certification (IUS 4-94) 8. REISSUE (October 1997) with Amendments No. 1, 2, approved in December 1983, June 1989 (IUS 4-84, 10-89)STATE STANDARD OF THE USSR UNION
Resistance standards
Grounding of stationary telegraph and telephone installations,
wire-broadoasting distribution points, radio-relay stations and CATV antennas.
Design objectives for resistance
By Decree of the USSR State Committee on Standards dated January 29, 1979 No. 304, the validity period was established
from 01.01. 1980
until 01.01. 1985
Failure to comply with the standard is punishable by law
This standard applies to station and line structures of wired communication installations, radio relay stations, radio broadcasting nodes, selective railway communication installations and antennas of collective television reception systems (CTRS), for which stationary grounding devices are equipped, and establishes standards for the resistance of grounding devices that ensure normal operation of the structure and installations listed above, as well as the safety of operating personnel.
The standard does not apply to grounding devices that are provided in special-purpose equipment.
The terms used in this standard and their definitions are given in the reference appendix.
1. GENERAL PROVISIONS
1.1. The following must be connected to the working-protective or protective grounding device using grounding wires using the shortest route:
one of the poles of the power supply installation; neutral wire of the windings of transformers of a power transformer substation or its own power plant that supplies equipment to communications enterprises. . radio relay station or radio broadcasting node station;
metal parts of power, cabinet and switching equipment;
metal pipelines for water supply and central heating, heating and other metal structures inside the building;
equipment and cable screens;
metal sheaths of cables, elements of protected circuits, lightning rods;
SKPT antennas subject to lightning protection in accordance with regulatory and technical documentation (hereinafter referred to as NTD).
The number of grounding wires and the procedure for connecting equipment and equipment to them are established in the technical documentation for equipment of a specific type.
1.2. Telecommunications enterprises should be equipped with a protective grounding device if there are no connecting lines and remote power supply circuits for equipment that use the ground as an electrical circuit wire.
1.3. At communications enterprises, one working and protective grounding device should be equipped if the “minus” of the current source is grounded (in this case, remote power circuits can be connected according to the “wire-ground” circuit) or the “plus” of the current source is grounded, but there are no remote power supply penalties according to the circuit "wire - ground". In this case, the connecting lines can use the ground as the wire of the electrical circuit. The circuit of the working and protective grounding device in the presence of remote power circuits must have two independent inputs into the building (before the grounding panel).
Enterprises should equip separate working and protective grounding devices if there are remote power circuits according to the “wire-to-ground” circuit with grounding of the “plus” of the current source.
2.1.3. The resistance of protective grounding devices at intermediate points that do not have power supply installations should be no more than 10 Ohms for soils with a resistivity of up to 100 Ohm-m and no more than 30 Ohm for soils with a resistivity of more than 100 Ohm-m.
2.1.4. The resistance of the working and protective grounding devices of MTS, using the ground as one of the wires of connecting lines of any type (custom, service from MTS and ATS, transit service lines, etc.), or in remote power supply (DP) circuits, should be no more values indicated in table. 1 and also meet the requirements clause 1.4;
Table 1
2.1.5. Resistance of working or working-protective grounding devices of linear equipment shops, support points; serviced amplification points feeding remotely unattended or regeneration points according to the “wire-to-ground” circuit must be determined based on the voltage drop on the grounding device from the remote supply current of no more than 12 V. However, the resistance of the working or operational-protective grounding devices should not be more than the values specified in clause 1.4.
2.2. Resistance standards of grounding devices for unattended amplification points of long-distance communication and intermediate points of selective railway communication
2.2.1. Maintenance-free amplification points (UPP), powered remotely according to the “wire-ground” circuit, in which the remote power supply circuit ends, must be equipped with three separate grounding devices - working, protective and line-protective.
Magnesium protectors used to protect metal PUP tanks from soil corrosion can be used as a protective grounding device.
In cases where it is not necessary to protect metal NUP tanks from soil corrosion, as well as when using non-metallic casings. NUP must be equipped with working and integrated protective grounding devices.
2.2.2. Unattended reinforcement points (NUP) and regeneration points (RP), powered remotely according to the “wire-to-wire” circuit, as well as UUP. powered according to the “wire-ground” circuit in which the remote power supply circuit does not end must be equipped with two separate grounding devices - protective and line-protective.
As grounding conductors for a protective grounding device, it is allowed to use magnesium protectors used to protect metal tanks NUP or RP from soil corrosion.
In cases where protection of metal tanks of the LUP or RP from corrosion is not required, as well as when using non-metallic bodies of the LUP or RP, a combined protective grounding device must be equipped.
2.2.3. The resistance of the working grounding device for LUPs powered by the “wire-ground” circuit should be no more than 10 Ohms for soils with a resistivity of up to 100 Ohm⋅m and no more than 30 Ohms for soils with a resistivity of more than 100 Ohm⋅m. In this case, the voltage drop from remote power currents across the resistance of the grounding device should be no more than 12 V for soils with a resistivity of up to 100 Ohm⋅m and no more than 36 V for soils with a resistivity of more than 100 Ohm⋅m.
Broadcasting, terminal and subscriber points that do not have power supply installations must be equipped with a protective grounding device with a resistance of no more than 10 Ohms for soil resistivity up to 100 Ohm-m and 20 Ohm for soils with a resistivity of more than 100 Ohm-m.
2.3.3. Telegraph stations and telegraph broadcasting points operating on single-wire circuits must be equipped with a working-protective and two measuring grounding devices. For telegraph stations where up to five telegraph devices are installed, it is allowed to use temporary measuring grounding devices.
The resistance of the working and protective grounding device depends on the number of single-wire telegraph circuits. fed into the station (see GOST 5238-73. drawings 1-6), should be no more than the values indicated in the table. 3.
Table 3
2.4. Resistance standards for grounding devices for city telephone exchanges and local railway communication stations
2.4.1. Telephone exchanges with a central battery (automatic telephone exchanges and manual telephone exchanges - RTS) must be equipped with three separate grounding devices - protective or operational-protective and two measuring ones.
In operating condition, all three grounding devices must be connected in parallel on the grounding panel and are disconnected only to measure the resistance of the protective or operational-protective grounding device.
2.4.2. Telephone exchanges that have connecting lines and do not use the ground as a current conductor (for example, connecting lines equipped with inductive sets of the RSL type) should be equipped with protective grounding devices (clause 1.2), the resistance of which should not exceed the values specified in g. 1.4.
Telephone exchanges that do not have supply transformer substations must be equipped with a protective grounding device with a resistance not exceeding the values specified in table. 4.
Table 4
2.4.3. Telephone exchanges that have redundant connecting lines using the ground as current conductors (according to clause 1.3) must be equipped with operational and protective grounding devices, the resistance of which should not exceed the values specified in the table. 5.
Table 5
Note. In cases where the connecting lines at the station are equipped with inductive and battery (using the ground as a current conductor) sets of the RSL type, the resistance value of the working and protective grounding is selected depending on the number of battery (polar) sets of the RSL type.
2.4.4. Unattended amplifier and regeneration points, powered remotely according to the “wire-to-wire” and “wire-to-ground” circuits, must be equipped with one protective grounding device, the resistance value of which must correspond to that given in clause 2.2.4.
2.5. Resistance standards for grounding devices of rural telephone exchanges (STO)
2.5.1. Rural telephone exchanges with a central battery (RTS and ATS) must be equipped with three separate grounding devices in accordance with paragraphs. 2.4.1—2.4.3.
2.5.2. Telephone exchanges with a capacity of up to 200 numbers may be equipped with one protective or operational-protective grounding device, and temporary grounding devices may be used as measuring grounding devices.
2.5.3. For compaction equipment of rural automatic telephone exchanges and radio stations in the case of (Use of the NUP “wire-to-wire” power supply system), one combined protective grounding device should be used. In this case, unattended amplification points should be equipped with protective grounding devices with a resistance not exceeding the value specified in clauses 2.1.2 and 2.1.3.
2.5.4. Maintenance-free amplification points powered remotely according to the “wire-ground” circuit should be equipped with two separate grounding devices: a working one and a line-protective one. The resistance of working and linear protective grounding devices should be no more than the values specified in paragraphs. 2.2.3 and 2.2.5.
2.6. Grounding resistance standards for telephone exchanges with a local battery (MB)
2.6.1. Telephone exchanges of the MB system operating on two-wire circuits must be equipped with three separate grounding devices - a protective one and two measuring ones. In operation, these three grounding devices must be connected in parallel on the grounding panel. When the station capacity is up to 200 numbers, it is allowed not to equip stationary measuring grounding devices, and when measuring the protective grounding device, use temporary grounding devices.
2.6.2. The resistance of the protective grounding device of MB stations operating on two-wire circuits should be no more than the values indicated in table. 2.
2.7. Resistance standards of grounding devices for stations and substations of radio broadcasting centers
2.7.1. Stations and substations of radio broadcasting units should be equipped with one protective or operational-protective grounding device. For control measurements of the resistance of the protective and working-protective grounding device, it is allowed to equip two stationary measuring groundings or use temporary grounding devices.
2.7.2. The resistance of the protective or working-protective grounding device must be no more than the values specified in clause 1.4 for amplification stations and substations, and no more than 10 Ohms for audio frequency transformer substations.
2.8. Resistance standards of grounding devices for combined installations of wired communications and radio broadcasting units
2.8.1. Fixed installations of wired communications of various sizes, located in one or nearby buildings and powered by one transformer substation: interurban, city, railway selective communications and others, as well as stations and substations of radio broadcasting nodes should be equipped with one common protective or working and protective grounding device. In this case, the resistance of the connecting electrodes from the grounding device should be taken into account.
2.8.2. The value of the resistance of the common grounding device must comply with the standards for each connected installation.
2.8.3. In unattended amplification points powered remotely by direct current, it is not allowed to combine a common grounding device with a working one.
2.9. Resistance standards for protection of grounding devices for long-distance communication lines
2.9.1. Resistance values of grounding devices for:
cascade protection spark gaps of types PR-7, IR-10, IIP-15 and IR-20;
spark gaps PR-0.2 or NR-0.3 - when installed on supports adjacent to the cable support or station;
spark gaps installed on overhead line wires to protect underground communication cables from moth strikes:
lightning rods installed on overhead line supports;
cables and metal sheaths of cables suspended on overhead line supports must be no more than the values specified in table 6.
2.9.2. Resistance of protective grounding devices for input, cable and other supports of long-distance communication lines and selective railway communications, on which, in accordance with the requirements of GOST 5238 - 73, it is required to turn on spark gaps of types IR-0.2 and IR-0.3 or gas-filled gaps, should be no more than the values indicated in Table 7.
Table 6
Table 7
1.10. The resistance of protective grounding devices for arresters of the PR-0.3 type, included to protect the blocking coils in the third circuits (see GOST 5238 - 73, Fig. 15), must be no more than the values specified in table 6.
1.11. The resistance of linear-protective grounding devices for metal cable sheaths, protective wires (cables) or busbars laid in the ground when protecting the cable from lightning strikes must be no more than the values specified in table 8.
Table 8
Note. The number of linear protective grounding devices, their placement on cable lines and the method of connecting metal shells, cables and screens with cables are established in the regulatory and technical documentation.
2.10. Resistance standards of protective grounding devices for lines of urban and rural telephone networks and local railway communication networks
2.10.1. Resistance of grounding devices for spark gaps of types IR-0.2; IR-0.3; IR-7; IR-10 and IR-15, connected according to diagrams. 27, 30-32 GOST 5238-73, should be no more than the values specified in table 6.
2.10.2. Resistance of grounding devices for carbon arresters of type UR-500 or gas-filled arresters of type R-27 installed in cable boxes at the junctions of overhead lines of GTS, STS and railway communication networks with cable lines (see GOST 5238-73, drawings 23 - 27 ), as well as for installation points of blockers (see GOST 5238 - 73, drawing 31), should be no more than the values specified in table. 9.
Table 9
2.10.3. The resistance of grounding devices for subscriber points (see GOST 5238-73, drawings 22-24; 29), for step-down transformers of payphone booths and lightning rods installed on overhead line supports should be no more than the values specified in table 10.
Table 10
2.10.4. The resistance of the grounding device for the metal sheath of the cable, the screen of the cable with non-metallic sheaths and the cable when suspended on the supports of pole and rack lines must be no more than the values specified in table 6.
2.10.5. The resistance of linear protective grounding devices when protecting GTS and STS cables from lightning strikes should be no more than the values specified in table 8.
2.11. Resistance standards for protective grounding devices on the lines of radio broadcasting nodes
2.11.1. Resistance of linear protective grounding devices for spark gaps of types IR-0.5 and IR-7.0 (see GOST 14857 - 76 drawings 1, 2), as well as for spark gaps of types IR-0.3 and IR-7, 0 (see GOST 14857-76 drawing 3.5.6) should be no more than the values specified in table 6.
2.11.2. The resistance of linear protective grounding devices for grounding the metal sheath and screen of cables laid in telephone sewer channels and collectors (at the beginning and end of the cable) must be no more than the values specified in table 8.
2.11.3. The resistance of linear protective grounding devices for lightning rods installed on PC overhead line supports must be no more than the values specified in table 10.
2.12. Resistance standards for grounding devices for radio relay stations
2.12.1. Radio relay stations, including those with compaction equipment, must be equipped with one protective grounding device. To monitor the resistance of the protective grounding device, it is allowed to equip two stationary measuring grounding devices or use temporary grounding devices. In operating condition, protective and measuring stationary grounding devices must be connected in parallel on the grounding panel.
2.12.2. The resistance of the protective grounding device must be no more than the value specified in clause 1.4.
2.13. Resistance standards for grounding devices for antennas of a collective television reception system
2.13.1 To protect SKPT antennas from dangerous voltages and currents arising from lightning discharges, a protective grounding device must be equipped. To monitor the resistance of the protective grounding device, it is allowed to use temporary measuring grounding devices.
2.13.2. It is allowed to connect lightning rods from two or more SKPT antennas located on the same building to one grounding device.
2.13.3 The design of the grounding device, as well as the lightning rod connecting the SKPT antenna to the grounding device, and the method of their connection are established in the regulatory and technical documentation.
2.13.4 The resistance of the grounding device for SKPT antennas should be no more than the values specified in table 6.
2.13.5 If there is a grounding device for the building on which the SKPT antennas are located (when protecting buildings from lightning strikes or to protect telephone communication and radio broadcasting equipment), it is allowed to connect lightning rods from the SKPT antennas to the existing grounding device. The resistance of the grounding device must be no more than the values specified in table 6.
APPLICATION
(informative)
TERMS USED IN THIS STANDARD AND THEIR DEFINITIONS
| Term | Definition |
| Grounding for wired communication installations, radio relay stations, radio broadcasting units, etc. | Intentional electrical connection of plant equipment or apparatus to a grounding device |
| Ground electrode | A metal conductor or group of conductors of any shape (pipe, angle, wire, etc.). in direct contact with the ground (soil) |
| Grounding conductor | Metal conductor connecting the grounded equipment or equipment to the grounding conductor |
| Grounding device | A set of grounding conductors and grounding conductors |
| Resistance of the grounding device or resistance to current spreading | The total electrical resistance of the grounding conductors and the ground electrode relative to the ground, expressed in ohms. The resistance of the grounding conductor relative to the ground is defined as the ratio of the voltage of the grounding conductor relative to the ground to the current passing through the grounding conductor into the ground |
| Soil resistivity | Electrical resistance exerted by soil with a volume of 1 m3 when current passes from one side of the soil to the opposite. The soil resistivity, denoted by Q and expressed in ohms per meter, should be measured taking into account seasonal variations, taking as the calculated most unfavorable value |
| Working grounding device | A device intended for connecting wired communication equipment and radio devices (radio broadcasting units, radio relay stations) to the ground for the purpose of using the ground as one of the wires of the electrical circuit |
| Protective grounding device | A device designed for connecting the neutral wires of the windings of power transformer substations, lightning rods, arresters, equipment screens and in-station installation wires to the ground. metal shells and armored covers of cables, metal tanks, unattended amplification points (UPP), metal parts of power equipment of wired communication installations and radio broadcasting units, installations for maintaining cables under pressure and other equipment that are not normally energized. but may become energized if the insulation of live wires is damaged. Protective grounding devices ensure that the potential of metal parts of equipment is equalized with the ground potential and thereby protect operating personnel and equipment from the occurrence of dangerous potential differences with respect to the ground. |
| Linear protective grounding device | A device that provides grounding of metal cable sheaths and armored covers along the cable route and at stations (NSP) where cable lines are connected, as well as on overhead lines for grounding lightning rods, cables and metal sheaths of cables, etc. In some cases It is allowed to combine protective and linear protective grounding devices. Such a grounding device is called a combined protective one. |
| Measuring grounding device | An auxiliary device designed for control measurements of the resistance of working, protective and working-protective grounding devices. The resistance of the working and protective grounding devices should be measured, as a rule, from the grounding panel at the station, including the grounding conductor towards the grounding conductor. The resistance of grounding devices on overhead and cable lines is measured directly on the line |
| Working and protective grounding device | A device that serves simultaneously as both a working and a protective grounding device. The resistance of the working and protective grounding device must be no more than the minimum value provided for the working and protective grounding devices. |
