7.1.1. This chapter of the Rules applies to electrical installations: residential buildings listed in SNiP 2.08.01-89 "Residential buildings"; public buildings listed in SNiP 2.08.02-89 "Public buildings and structures" (with the exception of buildings and premises listed in Ch. 7.2): administrative and household buildings listed in SNiP 2.09.04-87 "Administrative and domestic buildings" ; additional requirements may be imposed on electrical installations of unique and other special buildings not included in the above list.
The requirements of this chapter do not apply to special electrical installations in medical institutions, organizations and institutions of science and scientific service, to dispatching and communication systems, as well as to electrical installations, which, by their nature, should be attributed to electrical installations of industrial enterprises (workshops, boiler rooms, heating points, pumping stations, laundry factories, dry cleaning factories, etc.).
7.1.2. Electrical installations of buildings, in addition to the requirements of this chapter, must meet the requirements of chapters of section. 1-6 PUE to the extent that they are not changed by this chapter.
7.1.3. Input device (VU) - a set of structures, devices and devices installed at the input of the supply line to the building or to its separate part.
The input device, which also includes devices and devices of the outgoing lines, is called the input-distribution device (ASU).
7.1.4. The main distribution board (MSB) is a distribution board through which the entire building or its isolated part is supplied with electricity. The role of the main switchboard can be performed by an ASU or a low voltage board of a substation.
7.1.5. Distribution point (RP) - a device in which protection devices and switching devices (or only protection devices) are installed for individual electrical receivers or their groups (electric motors, group panels).
7.1.6. A group shield is a device in which protection devices and switching devices (or only protection devices) are installed for individual groups of lamps, plug sockets and stationary electrical receivers.
7.1.7. Apartment panel - a group panel installed in an apartment and designed to connect the mains supplying lamps, sockets and stationary electrical receivers of the apartment.
7.1.8. Floor switchboard - a switchboard installed on the floors of residential buildings and intended for powering apartments or apartment panels.
7.1.9. Switchboard room - room. accessible only for qualified service personnel, in which VU, VRU, main switchboard and other switchgears are installed.
7.1.10. Supply network - a network from a substation switchgear or a branch from overhead power lines to VU, VRU, main switchboard.
7.1.11. Distribution network - a network from VU, VRU, main switchboard to distribution points and panels.
7.1.12. Group network - a network from panels and distribution points to lamps, plug sockets and other electrical receivers.
General requirements. Power supply
7.1.13. The power supply of electrical consumers should be carried out from the 380/220 V network with the system earthing TN-S or TN-C-S.
When reconstructing residential and public buildings with a voltage of 220/127 V or 3 x 220 V, it is necessary to provide for the transfer of the network to a voltage of 380/220 V with a TN-S or TN-C-S grounding system.
7.1.14. External power supply of buildings must meet the requirements of Chapter 1.2.
7.1.15. In dormitories of various institutions, in schools and other educational institutions etc. the construction of built-in and attached substations is not allowed.
In residential buildings, in exceptional cases, it is allowed to place built-in and attached substations using dry transformers in agreement with the state supervision authorities, while the sanitary requirements for limiting the level of noise and vibration must be fully met in accordance with current standards.
The device and placement of built-in, attached and free-standing substations should be carried out in accordance with the requirements of chapters of Sect. 4.
7.1.16. It is recommended to supply power and lighting electrical receivers from the same transformers.
7.1.17. The location and layout of transformer substations should provide for the possibility of round-the-clock unhindered access to them by the personnel of the power supply organization.
7.1.18. Power supply of safety lighting and evacuation lighting must be carried out in accordance with the requirements of Ch. 6.1 and 6.2, as well as SNiP 23-05-95 "Natural and artificial lighting".
7.1.19. If there are elevators in the building, which are also intended for the transportation of fire departments, their power supply must be provided in accordance with the requirements of Ch. 7.4.
7.1.20. The electrical networks of buildings should be designed to power advertising lighting, showcases, facades, illumination, outdoor, fire-prevention devices, dispatching systems, local television networks, fire hydrant light indicators, security signs, bell and other alarms, lights of light barriers, etc. in accordance with the design assignment.
7.1.21. When powering single-phase consumers of buildings from a multiphase distribution network, it is allowed for different groups of single-phase consumers to have common N and PE conductors (five-wire network) laid directly from the ASP, the combination of N and PE conductors (four-wire network with a PEN conductor) is not allowed.
When supplying single-phase consumers from a multiphase supply network with branches from overhead lines, when the PEN conductor of the overhead line is common for groups of single-phase consumers powered from different phases, it is recommended to provide a protective shutdown of consumers when the voltage exceeds the allowable voltage arising from the load asymmetry in the event of a PEN break conductor. Disconnection should be carried out at the entrance to the building, for example, by acting on the shunt release of the input circuit breaker by means of an overvoltage relay, while both phase (L) and zero working (N) conductors should be disconnected.
When choosing devices and devices installed at the input, preference, other things being equal, should be given to devices and devices that remain operational when the voltage is exceeded above the permissible voltage arising from load asymmetry when the PEN or N conductor is broken, while their switching and other performance may not be met.
In all cases, it is prohibited to have switching contact and non-contact elements in PE and PEN conductor circuits.
Connections that can be disassembled with a tool are allowed, as well as connectors specially designed for this purpose.
Input devices, switchboards, distribution points, group boxes
7.1.22. A VU or ASU must be installed at the entrance to the building. One or more VU or ASU can be installed in the building.
If there are several economically isolated consumers in the building, each of them is recommended to install an independent VU or ASU.
Power supply to consumers located in other buildings is also allowed from the ASP, provided that these consumers are functionally connected.
With branches from overhead lines with a design current of up to 25 A, the VU or VU at the inputs to the building may not be installed if the distance from the branch to the group panel, which in this case performs the functions of the VU, is not more than 3 m.This section of the network should be performed with a flexible copper cable with with a cross-section of conductors of at least 4 mm 2, flame-retardant, laid in a steel pipe, while the requirements for ensuring a reliable contact connection with branch wires must be met.
For air inlet, surge suppressors must be installed.
7.1.23. Before entering buildings, it is not allowed to install additional cable boxes to separate the service area of \u200b\u200bexternal supply networks and networks inside the building. Such division must be performed in the ASU or the main switchboard.
7.1.24. VU, VRU, main switchboard must have protection devices at all inputs of supply lines and on all outgoing lines.
7.1.25. Control devices should be installed at the input of the supply lines to the VU, VRU, main switchboard. On outgoing lines, control devices can be installed either on each line, or be common to several lines.
The circuit breaker should be regarded as a protection and control device.
7.1.26. Control devices, regardless of their presence at the beginning of the supply line, must be installed at the inputs of the supply lines in retail premises, utilities, administrative premises, etc., as well as in the premises of consumers, isolated in administrative terms.
7.1.27. The floor panel should be installed at a distance of no more than 3 m along the length of the wiring from the supply riser, taking into account the requirements of Ch. 3.1.
7.1.28. VU, VRU, main switchboard, as a rule, should be installed in switchboard rooms accessible only to service personnel. In areas prone to flooding, they should be installed above the flood level.
VU, VRU, main switchboard can be located in rooms allocated in operated dry basements, provided that these rooms are accessible to service personnel and separated from other rooms by partitions with a fire resistance limit of at least 0.75 hours.
When placing VU, ASU, main switchboard, distribution points and group boards outside the switchboard rooms, they should be installed in convenient and accessible places for maintenance, in cabinets with a shell protection degree of at least IP31.
The distance from pipelines (water supply, heating, sewerage, internal drains), gas pipelines and gas meters to the installation site must be at least 1 m.
7.1.29. Switchboard rooms, as well as VU, VRU, main switchboard, are not allowed to be located under toilets, bathrooms, showers, kitchens (except kitchens of apartments), sinks, washing and steam rooms of baths and other rooms associated with wet technological processes, except for cases when special measures have been taken to reliable waterproofingpreventing the ingress of moisture into the premises where the switchgear is installed.
It is not recommended to lay pipelines (water supply, heating) through switch rooms.
Pipelines (water supply, heating), ventilation and other ducts laid through the switchboard rooms should not have branches within the premises (with the exception of a branch to heating device the panel room itself), as well as hatches, gate valves, flanges, valves, etc.
Laying through these rooms gas and pipelines with flammable liquids, sewerage and internal drains are not allowed.
Doors of electrical control rooms must open outward.
7.1.30. The premises in which the ASU, the main switchboard are installed must have natural ventilation, electric lighting. The room temperature should not be lower than +5 o C.
7.1.31. Electrical circuits within VU, VRU, main switchboard, distribution points, group shields should be performed with wires with copper conductors.
Electrical wiring and cable lines
7.1.32. Internal wiring must be carried out taking into account the following:
1. Electrical installations of different organizations, separated in administrative terms, located in the same building, can be connected by branches to a common supply line or powered by separate lines from the ASU or the main switchboard.
2. It is allowed to connect several risers to one line. On the branches to each riser supplying apartments in residential buildings with more than 5 floors, a control device should be installed, combined with a protection device.
3. In residential buildings, lamps for staircases, lobbies, halls, floor corridors and other indoor premises outside apartments should be powered by independent lines from the ASU or separate group shields powered by the ASU. Connecting these lamps to floor and apartment shields is not allowed.
4. For staircases and corridors with natural light, it is recommended to provide automatic control of electric lighting, depending on the illumination created by natural light.
5. It is recommended to supply power to non-residential electrical installations by separate lines.
7.1.33. The power supply networks from substations to VU, ASU, MSB must be protected from short-circuit currents.
7.1.34. In buildings, cables and wires with copper conductors should be used
Supply and distribution networks, as a rule, must be carried out with cables and wires with aluminum conductors, if their design cross-section is 16 mm 2 or more.
Power supply of individual electrical receivers related to the engineering equipment of buildings (pumps, fans, heaters, air conditioning units, etc.) can be carried out with wires or cables with aluminum conductors with a cross section of at least 2.5 mm 2.
In museums, art galleries, exhibition premises, it is allowed to use lighting bus ducts with a degree of protection IP20, in which branch devices to luminaires have detachable contact connections located inside the bus duct box at the time of switching, and bus ducts with a degree of protection IP44, in which branches to the luminaires are made with using plug connectors that ensure the branch circuit is open until the plug is removed from the socket.
In these rooms, the lighting bus ducts must be powered from distribution points by independent lines.
In residential buildings section copper conductors must correspond to the calculated values, but be not less than those indicated in table 7.1.1.
1 Until 2001, according to the existing construction work, it is allowed to use wires and cables with aluminum conductors.
Table 7.1.1. The smallest permissible cross-sections of cables and wires of electrical networks in residential buildings.
7.1.35. In residential buildings, the laying of vertical sections of the distribution network inside apartments is not allowed.
It is forbidden to lay wires and cables from the floor panel in a common pipe, common duct or channel supplying the lines of different apartments.
Flame retardant gasket in a common pipe, common duct or duct is allowed building structures, made of non-combustible materials, wires and cables of supply lines of apartments together with wires and cables of group lines of working lighting of staircases, floor-by-storey corridors and other indoor premises.
7.1.36. In all buildings, the lines of the group network, laid from group, floor and apartment shields to general lighting fixtures, sockets and stationary electrical receivers, must be three-wire (phase - L, zero working - N and zero protective - PE conductors).
It is not allowed to combine zero working and zero protective conductors of different group lines.
Zero working and zero protective conductors are not allowed to be connected on shields under a common terminal.
The cross-sections of the conductors must meet the requirements of clause 7.1.45.
7.1.37. The electrical wiring in the premises should be removable: hidden - in the channels of building structures, embedded pipes; openly - in electrical skirting boards, boxes, etc.
In technical floors, undergrounds, unheated basements, attics, ventilation chambers, damp and especially damp rooms, it is recommended to carry out electrical wiring openly.
In buildings with building structures made of non-combustible materials, it is allowed to use a cable or insulated wires in a protective sheath for non-replaceable monolithic laying of group networks in the furrows of walls, partitions, ceilings, under plaster, in the floor preparation layer or in the voids of building structures. The use of non-replaceable monolithic laying of wires in panels of walls, partitions and ceilings, made during their manufacture at factories of the building industry or performed at the assembly joints of panels during the installation of buildings, is not allowed.
7.1.38. Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and should be carried out: behind ceilings and in voids of partitions made of combustible materials in metal pipeswith localization ability, and in closed boxes; behind ceilings and in partitions made of non-combustible materials 2 - in pipes and boxes made of non-combustible materials, as well as flame-retardant cables. In this case, the possibility of replacing wires and cables must be ensured.
2 Under the suspended ceilings made of non-combustible materials, we mean those ceilings that are made of non-combustible materials, while other building structures located above the suspended ceilings, including intermediate floors, are also made of non-combustible materials.
7.1.39. In rooms for cooking and eating, with the exception of apartment kitchens, open laying of cables is allowed. Open laying of wires in these rooms is not allowed.
In the kitchens of apartments, the same types of electrical wiring can be used as in living rooms and corridors.
7.1.40. In saunas, bathrooms, toilets, showers, as a rule, hidden electrical wiring should be used. Open cable routing is allowed.
In saunas, bathrooms, lavatories, shower rooms, it is not allowed to lay wires with metal sheaths, in metal pipes and metal sleeves.
In saunas for zones 3 and 4 according to GOST R 50571.12-96 "Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 703. Rooms containing heaters for saunas" electrical wiring with a permissible insulation temperature of 170 o C. must be used.
7.1.41. Electrical wiring in attics must be carried out in accordance with the requirements of Sect. 2.
7.1.42. Through the basements and technical undergrounds of the building sections, it is allowed to lay power cables with a voltage of up to 1 kV, supplying electrical receivers of other sections of the building. These cables are not considered as transit cables; laying transit cables through basements and technical undergrounds of buildings is prohibited.
7.1.43. Open laying of transit cables and wires through storerooms and warehouses is not allowed.
7.1.44. The lines supplying refrigeration units of trade and public catering enterprises must be laid from the ASU or main switchboard of these enterprises.
7.1.45. The selection of the cross-section of the conductors should be carried out in accordance with the requirements of the relevant chapters of the PUE.
Single-phase two- and three-wire lines, as well as three-phase four- and five-wire lines when supplying single-phase loads, must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors.
Three-phase four- and five-wire lines when supplying three-phase symmetrical loads must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors, if the phase conductors have a cross-section of up to 16 mm 2 for copper and 25 mm 2 for aluminum, and with large cross-sections - not less than 50% of the cross section of the phase conductors.
The cross-section of PEN conductors must be at least the cross-section of N conductors and at least 10 mm 2 for copper and 16 mm 2 for aluminum, regardless of the cross-section of the phase conductors.
The cross-section of PE conductors should be equal to the cross-section of the phase conductors with a cross-section of the latter up to 16 mm 2, 16 mm 2 with a cross-section of the phase conductors from 16 to 35 mm 2 and 50% of the cross-section of the phase conductors with large cross-sections.
The cross-section of PE conductors that are not part of the cable must be at least 2.5 mm 2 - in the presence of mechanical protection and 4 mm 2 - in its absence.
Internal electrical equipment
7.1.46. In rooms for cooking, except for kitchens of apartments, lamps with incandescent lamps installed above workplaces (stoves, tables, etc.) must have protective glass below. Luminaires with fluorescent lamps should have grilles or grids or lamp holders to prevent the lamps from falling out.
7.1.47. In bathrooms, showers and lavatories, only that electrical equipment should be used that is specially designed for installation in the corresponding zones of the specified premises in accordance with GOST R 50571.11-96 "Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 701. Bathrooms and showers", the following requirements must be met:
- - electrical equipment must have a degree of water protection not lower than:
- in zone 0 - IPx7;
- in zone 1 - IPx5;
- in zone 2 - IPx4 (IPx5 - in public baths);
- in zone 3 - IPx1 (IPx5 - in public baths);
- - in zone 0, electrical appliances with a voltage of up to 12 V, intended for use in a bath, can be used, and the power supply must be located outside this zone:
- - only water heaters can be installed in zone 1;
- - in zone 2, water heaters and lamps of protection class 2 can be installed;
- - in zones 0, 1 and 2 it is not allowed to install junction boxes, switchgear and control devices.
7.1.48. The installation of plug sockets in bathrooms, showers, soap rooms of baths, rooms containing sauna heaters (hereinafter referred to as "saunas"), as well as in washing rooms of laundries, is not allowed, with the exception of the bathrooms of apartments and hotel rooms.
In the bathrooms of apartments and hotel rooms, it is allowed to install plug sockets in zone 3 in accordance with GOST R 50571.11-96, connected to the network through isolation transformers or protected by a residual current device that responds to a differential current not exceeding 30 mA.
Any switches and sockets should be located at least 0.6 m from the doorway of the shower stall.
7.1.49. In buildings with a three-wire network (see clause 7.1.36.), Plug sockets for a current of at least 10 A with a protective contact must be installed.
Sockets installed in apartments, dormitory living rooms, as well as in rooms for children in childcare facilities (kindergartens, nurseries, schools, etc.) must have a protective device that automatically closes the socket when the plug is removed.
7.1.50. Minimum distance from switches, plug sockets and electrical installation elements to gas pipelines must be at least 0.5 m.
In rooms for children in childcare facilities (kindergartens, nurseries, schools, etc.), switches should be installed at a height of 1.8 m from the floor.
7.1.52. In saunas, bathrooms, lavatories, soap rooms, baths, steam rooms, washing rooms, laundries, etc. installation of switchgear and control devices is not allowed.
In the washbasin rooms and in zones 1 and 2 (GOST R 50571.11-96) of bathrooms and shower rooms, it is allowed to install switches operated by a cord.
7.1.53. The disconnecting devices of the lighting network of attics with elements of building structures (roof, trusses, rafters, beams, etc.) made of combustible materials must be installed outside the attic.
7.1.54. Switches for working, safety and evacuation lighting in premises intended for large numbers of people (for example, commercial premises of shops, canteens, hotel lobbies, etc.) should be accessible only to service personnel.
7.1.55. A luminaire must be installed above each building entrance.
7.1.56. House license plates and fire hydrant signs installed on the outer walls of buildings should be illuminated. Electric light sources for license plates and hydrant indicators must be powered from the building's internal lighting network, and fire hydrant indicators installed on outdoor lighting poles should be supplied from the outdoor lighting network.
7.1.57. Fire-fighting devices and burglar alarms, regardless of the category of the building's power supply reliability, must be powered from two inputs, and in their absence - two lines from one input. Switching from one line to another should be done automatically.
7.1.58. Electric motors installed in the attic, distribution points, separately installed switching devices and protection devices must have a degree of protection of at least IP44.
Electricity metering
7.1.59. In residential buildings, one single or three-phase settlement meter (with three-phase input) should be installed for each apartment.
7.1.60. Settlement meters in public buildings, in which several consumers of electricity are located, should be provided for each consumer, isolated in administrative and economic terms (ateliers, shops, workshops, warehouses, housing maintenance offices, etc.).
7.1.61. In public buildings, settlement electricity meters should be installed on the ASU (MSB) at the points of balance delineation with the power supply organization. In the presence of built-in or attached transformer substations, the power of which is fully used by the consumers of this building, settlement meters should be installed at the low voltage terminals of power transformers on combined low voltage boards, which are at the same time the ASU of the building.
ASP and metering devices of different subscribers located in the same building can be installed in one common room. By agreement with the energy supplying organization, settlement meters can be installed at one of the consumers, from which the other consumers located in this building are powered. At the same time, control meters should be installed at the inputs of the supply lines in the premises of these other consumers for settlement with the main subscriber.
7.1.62. It is recommended to install calculation meters for the general house load of residential buildings (lighting of stairwells, house management offices, courtyard lighting, etc.) in the ASU cabinets or on the main switchboard panels.
When installing apartment panels in the hallways of apartments, meters, as a rule, should be installed on these panels; installation of meters on floor panels is allowed.
7.1.64. For safe replacement of a meter directly connected to the network, a switching device must be provided in front of each meter to remove voltage from all phases connected to the meter.
Disconnecting devices for removing voltage from settlement meters located in apartments should be located outside the apartment.
7.1.65. After the meter connected directly to the network, a protection device must be installed. If after the counter there are several lines equipped with protection devices, the installation of a general protection device is not required.
Protective security measures
7.1.67. Grounding and protective measures for the safety of electrical installations of buildings must be carried out in accordance with the requirements of Ch. 1.7 and additional requirements given in this section.
7.1.68. In all rooms, it is necessary to connect open conductive parts of general lighting fixtures and stationary electrical receivers (electric stoves, boilers, household air conditioners, electric towels, etc.) to the zero protective conductor.
7.1.69. In the premises of buildings, metal cases of single-phase portable electrical appliances and desktop office equipment of class I in accordance with GOST 12.2.007.0-75 "SSBT. Electrical products. General requirements safety "must be connected to the protective conductors of the three-wire group line (see clause 7.1.36.).
The protective conductors must be connected metal frames partitions, doors and frames used for cable routing.
7.1.70. In rooms without increased danger, it is allowed to use pendant lamps that are not equipped with clamps for connecting protective conductors, provided that the hook for their suspension is insulated. The requirements of this clause do not cancel the requirements of clause 7.1.36. and are not the basis for two-wire wiring.
7.1.71. To protect group lines supplying sockets for portable electrical devices, it is recommended to provide residual current devices (RCDs).
7.1.72. If the overcurrent protective device (circuit breaker, fuse) does not provide an automatic shutdown time of 0.4 s at rated voltage 220 V due to low values \u200b\u200bof short-circuit currents and the installation (apartment) is not covered by the equipotential bonding system, the installation of an RCD is mandatory.
7.1.73. When installing an RCD, the selectivity requirements must be consistently met. With two- and multi-stage circuits, the RCD located closer to the power source must have a setting and the response time at least 3 times longer than that of an RCD located closer to the consumer.
7.1.74. In the area of \u200b\u200bthe RCD, the neutral working conductor should not have connections with grounded elements and a zero protective conductor.
7.1.75. In all cases, the use of an RCD must ensure reliable switching of load circuits, taking into account possible overloads.
It is not allowed to use RCDs in group lines that do not have overcurrent protection, without an additional device providing this protection.
When using RCDs that do not have overcurrent protection, it is necessary to check them in overcurrent modes, taking into account the protective characteristics of the upstream device that provides overcurrent protection.
7.1.77. In residential buildings, it is not allowed to use RCDs that automatically disconnect the consumer from the network when the network voltage disappears or is impermissible. In this case, the RCD must remain operational for at least 5 s when the voltage drops to 50% of the nominal.
7.1.78. In buildings, RCDs of type "A" can be used, which react to both alternating and pulsating fault currents, or "AC", which react only to alternating leakage currents.
The source of the pulsating current is, for example, washing machines with speed controllers, adjustable light sources, televisions, VCRs, personal computers, etc.
7.1.79. In group networks supplying plug sockets, an RCD with a rated operating current of no more than 30 mA should be used.
It is allowed to connect several group lines to one RCD through separate circuit breakers (fuses).
Installation of RCDs in lines supplying stationary equipment and lamps, as well as in general lighting networks, is usually not required.
7.1.81. Installation of an RCD is prohibited for electrical receivers, the disconnection of which can lead to situations that are dangerous for consumers (shutdown of the fire alarm, etc.).
7.1.82. It is mandatory to install an RCD with a rated operating current of no more than 30 mA for group lines supplying outlet networks located outdoors and in rooms of especially dangerous and with increased danger, for example, in zone 3 of bathrooms and shower rooms of apartments and hotel rooms.
7.1.83. The total leakage current of the network, taking into account the connected stationary and portable electrical receivers in normal operation, should not exceed 1/3 of the rated current of the RCD. In the absence of data, the leakage current of electrical receivers should be taken at the rate of 0.4 mA per 1 A of the load current, and the leakage current of the network - at the rate of 10 μA per 1 m of the length of the phase conductor.
7.1.84. To increase the level of protection against fire in case of short circuits to grounded parts, when the current value is insufficient to trigger the overcurrent protection, at the input to an apartment, individual house, etc. it is recommended to install an RCD with a tripping current up to 300 mA.
7.1.85. For residential buildings when the requirements of clause 7.1.83 are met. RCD functions according to PP. 7.1.79. and 7.1.84. can be performed by one device with an operating current of no more than 30 mA.
7.1.86. If the RCD is intended for protection against electric shock and fire, or only for protection against fire, then it must disconnect both phase and neutral working conductors; overcurrent protection in the neutral working conductor is not required.
7.1.87. At the entrance to the building, a potential equalization system must be performed by combining the following conductive parts:
- main (trunk) protective conductor;
- main (trunk) grounding conductor or main grounding clamp;
- steel pipes communications of buildings and between buildings;
- metal parts of building structures, lightning protection, central heating, ventilation and air conditioning systems. Such conductive parts must be interconnected at the entrance to the building.
7.1.88. All exposed conductive parts of stationary electrical installations, third-party conductive parts and neutral protective conductors of all electrical equipment (including sockets) must be connected to the additional potential equalization system.
For bathrooms and shower rooms, an additional potential equalization system is mandatory and must include, among other things, the connection of third-party conductive parts that extend outside the premises. If there is no electrical equipment with zero protective conductors connected to the potential equalization system, then the potential equalization system should be connected to the PE bus (terminal) at the input. Heating elements embedded in the floor must be covered with a grounded metal mesh or grounded metal sheath connected to an equipotential bonding system. As an additional protection for heating elements, it is recommended to use an RCD for a current up to 30 mA.
It is not allowed to use local equipotential bonding systems for saunas, bathrooms and showers.
The requirements of this chapter are interrelated. It should be borne in mind that partial fulfillment of a set of requirements for electrical installations of buildings can lead to a decrease in the level of electrical safety.
7.1.1. This chapter of the Rules applies to electrical installations: residential buildings listed in SNiP 2.08.01-89 "Residential buildings"; public buildings listed in SNiP 2.08.02-89 "Public buildings and structures" (with the exception of buildings and premises listed in Chapter 7.2); administrative and utility buildings listed in SNiP 2.09.04-87 "Administrative and utility buildings"; additional requirements may be imposed on electrical installations of unique and other special buildings not included in the above list.
The requirements of this chapter do not apply to special electrical installations in medical institutions, organizations and institutions of science and scientific service, to dispatching and communication systems, as well as to electrical installations, which by their nature should be attributed to electrical installations of industrial enterprises (workshops, boiler rooms, heating points, pumping stations, laundry factories, dry cleaning factories, etc.).
7.1.2. Electrical installations of buildings, in addition to the requirements of this chapter, must meet the requirements of chapters of section. 1-6 PUE to the extent that they are not changed by this chapter.
7.1.3. Input device (VU) - a set of structures, devices and devices installed at the input of the supply line to the building or to its separate part.
The input device, which also includes devices and devices of the outgoing lines, is called the input-distribution device (ASU).
7.1.4. The main distribution board (MSB) is a distribution board through which the entire building or its isolated part is supplied with electricity. The role of the main switchboard can be performed by an ASU or a low voltage board of a substation.
7.1.5. Distribution point (RP) is a device in which protection devices and switching devices (or only protection devices) are installed for individual electrical receivers or their groups (electric motors, group shields).
7.1.6. A group shield is a device in which protection devices and switching devices (or only protection devices) are installed for individual groups of lamps, plug sockets and stationary electrical receivers.
7.1.7. Apartment panel - a group panel installed in an apartment and designed to connect the mains supplying lamps, sockets and stationary electrical receivers of the apartment.
7.1.8. Floor switchboard - a switchboard installed on the floors of residential buildings and designed to power apartments or apartment panels.
7.1.9. Switchboard room - a room accessible only for qualified service personnel, in which VU, VRU, main switchboard and other switchgears are installed.
7.1.10. Supply network - a network from a substation switchgear or a branch from overhead power lines to VU, VRU, main switchboard.
7.1.11. Distribution network - a network from VU, VRU, main switchboard to distribution points and panels.
7.1.12. Group network - a network from panels and distribution points to lamps, plug sockets and other electrical receivers.
General requirements. Power supply
7.1.13. The power supply of electrical consumers should be carried out from a 380/220 V network with a TN-S or TN-C-S grounding system.
When reconstructing residential and public buildings with a voltage of 220/127 V or 3 x 220 V, it is necessary to provide for the transfer of the network to a voltage of 380/220 V with a TN-S or TN-C-S grounding system.
7.1.14. External power supply of buildings must meet the requirements of Chapter 1.2.
7.1.15. In dormitories of various institutions, in schools and other educational institutions, etc. the construction of built-in and attached substations is not allowed.
In residential buildings, in exceptional cases, it is allowed to place built-in and attached substations using dry transformers in agreement with the state supervision authorities, while the sanitary requirements for limiting the level of noise and vibration must be fully met in accordance with current standards.
The device and placement of built-in, attached and free-standing substations should be carried out in accordance with the requirements of chapters of Sect. 4.
7.1.16. It is recommended to supply power and lighting electrical receivers from the same transformers.
7.1.17. The location and layout of transformer substations should provide for the possibility of round-the-clock unhindered access to them by the personnel of the power supply organization.
7.1.18. Power supply of safety lighting and evacuation lighting must be carried out in accordance with the requirements of Ch. 6.1 and 6.2, as well as SNiP 23-05-95 "Natural and artificial lighting".
7.1.19. If there are elevators in the building, which are also intended for the transportation of fire brigades, their power supply must be provided in accordance with the requirements of Ch. 7.8.
7.1.20. The electrical networks of buildings should be designed to power advertising lighting, showcases, facades, illumination, outdoor, fire-prevention devices, dispatching systems, local television networks, fire hydrant light indicators, security signs, bell and other alarms, lights of light barriers, etc. in accordance with the design assignment.
7.1.21. When powering single-phase consumers of buildings from a multiphase distribution network, it is allowed for different groups of single-phase consumers to have common N and PE conductors (five-wire network) laid directly from the ASP, the combination of N and PE conductors (four-wire network with a PEN conductor) is not allowed.
When supplying single-phase consumers from a multiphase supply network with branches from overhead lines, when the PEN conductor of the overhead line is common for groups of single-phase consumers powered from different phases, it is recommended to provide a protective shutdown of consumers when the voltage exceeds the allowable voltage arising from load asymmetry in case of PEN conductor. Disconnection should be carried out at the entrance to the building, for example, by acting on the shunt release of the input circuit breaker by means of an overvoltage relay, while both phase (L) and zero working (N) conductors should be disconnected.
When choosing devices and devices installed at the input, preference, other things being equal, should be given to devices and devices that remain operational when the voltage is exceeded above the permissible voltage arising from load asymmetry when a PEN or N conductor is broken, while their switching and other performance may not be met.
In all cases, it is forbidden to have switching contact and non-contact elements in the PE and PEN conductor circuits.
Connections that can be disassembled with a tool are allowed, as well as connectors specially designed for this purpose.
Input devices, switchboards, distribution points, group boxes
7.1.22. A VU or ASU must be installed at the entrance to the building. One or more VU or ASU can be installed in the building.
If there are several economically isolated consumers in the building, each of them is recommended to install an independent VU or ASU.
Power supply to consumers located in other buildings is also allowed from the ASP, provided that these consumers are functionally connected.
With branches from overhead lines with a design current of up to 25 A, the VU or VU at the inputs to the building may not be installed if the distance from the branch to the group panel, which in this case performs the functions of the VU, is not more than 3 m.This section of the network should be performed with a flexible copper cable with with a cross-section of conductors of at least 4 mm 2, flame-retardant, laid in a steel pipe, while the requirements for ensuring a reliable contact connection with branch wires must be met.
For air inlet, surge suppressors must be installed.
7.1.23. Before entering buildings, it is not allowed to install additional cable boxes to separate the service area of \u200b\u200bexternal supply networks and networks inside the building. Such division must be performed in the ASU or the main switchboard.
7.1.24. VU, VRU, main switchboard must have protection devices at all inputs of supply lines and on all outgoing lines.
7.1.25. Control devices should be installed at the input of the supply lines to the VU, VRU, main switchboard. On outgoing lines, control devices can be installed either on each line, or be common to several lines.
The circuit breaker should be regarded as a protection and control device.
7.1.26. Control devices, regardless of their presence at the beginning of the supply line, must be installed at the inputs of the supply lines in retail premises, utilities, administrative premises, etc., as well as in the premises of consumers, isolated in administrative terms.
7.1.27. The floor panel should be installed at a distance of no more than 3 m along the length of the wiring from the supply riser, taking into account the requirements of Ch. 3.1.
7.1.28. VU, VRU, main switchboard, as a rule, should be installed in switchboard rooms accessible only to service personnel. In areas prone to flooding, they should be installed above the flood level.
VU, VRU, main switchboard can be located in rooms allocated in operated dry basements, provided that these rooms are accessible to service personnel and separated from other rooms by partitions with a fire resistance limit of at least 0.75 hours.
When placing VU, ASU, main switchboard, distribution points and group boards outside the switchboard rooms, they should be installed in convenient and accessible places for maintenance, in cabinets with a shell protection degree of at least IP31.
The distance from pipelines (water supply, heating, sewerage, internal drains), gas pipelines and gas meters to the installation site must be at least 1 m.
7.1.29. Switchboard rooms, as well as VU, VRU, main switchboard, are not allowed to be located under toilets, bathrooms, showers, kitchens (except kitchens of apartments), sinks, washing and steam rooms of baths and other rooms associated with wet technological processes, except for cases when special measures have been taken to ensure reliable waterproofing to prevent moisture from entering the premises where the switchgear is installed.
It is not recommended to lay pipelines (water supply, heating) through switch rooms.
Pipelines (water supply, heating), ventilation and other ducts laid through the switchboard rooms should not have branches within the room (except for a branch to the heating device of the switchboard room itself), as well as hatches, valves, flanges, valves, etc.
Laying through these rooms gas and pipelines with flammable liquids, sewerage and internal drains are not allowed.
Doors of electrical control rooms must open outward.
7.1.30. The rooms in which the ASU, the main switchboard are installed, must have natural ventilation, electric lighting. The room temperature should not be lower than + 5 ° С.
7.1.31. Electrical circuits within VU, VRU, main switchboard, distribution points, group shields should be performed with wires with copper conductors.
Electrical wiring and cable lines
7.1.32. Internal wiring must be carried out taking into account the following:
1. Electrical installations of different organizations, separated in administrative terms, located in the same building, can be connected by branches to a common supply line or powered by separate lines from the ASU or the main switchboard.
2. It is allowed to connect several risers to one line. On the branches to each riser supplying apartments in residential buildings with more than 5 floors, a control device should be installed, combined with a protection device.
3. In residential buildings, lamps for staircases, lobbies, halls, floor corridors and other indoor premises outside apartments should be powered by independent lines from the ASU or separate group shields powered by the ASU. Connecting these lamps to floor and apartment shields is not allowed.
4. For staircases and corridors with natural light, it is recommended to provide automatic control of electric lighting, depending on the illumination created by natural light.
5. It is recommended to supply power to non-residential electrical installations by separate lines.
7.1.33. The power supply networks from substations to VU, ASU, MSB must be protected from short-circuit currents.
7.1.34. In buildings, use copper cables and wires *.
Supply and distribution networks, as a rule, must be carried out with cables and wires with aluminum conductors, if their design cross-section is 16 mm 2 or more.
Power supply of individual electrical receivers related to the engineering equipment of buildings (pumps, fans, heaters, air conditioning units, etc.) can be carried out with wires or cables with aluminum conductors with a cross section of at least 2.5 mm 2.
In museums, art galleries, exhibition premises, it is allowed to use lighting bus ducts with IP20 protection degree, in which branching devices to luminaires have detachable contact connections located inside the bus duct box at the time of switching, and bus ducts with IP44 protection degree, in which branches to the lamps are made with by means of plug connectors that ensure the break of the branch circuit until the plug is removed from the socket.
In these rooms, the lighting bus ducts must be powered from distribution points by independent lines.
In residential buildings, the cross-sections of copper conductors must correspond to the calculated values, but not less than those indicated in table 7.1.1.
____________
* Until 2001, according to the existing construction reserve, it is allowed to use wires and cables with aluminum conductors.
7.1.35. In residential buildings, the laying of vertical sections of the distribution network inside apartments is not allowed.
It is forbidden to lay wires and cables from the floor panel in a common pipe, common duct or channel supplying the lines of different apartments.
A flame-retardant laying in a common pipe, common box or channel of building structures made of non-combustible materials, wires and cables of supply lines of apartments, together with wires and cables of group lines of working lighting of staircases, floor corridors and other indoor premises, is allowed.
Table 7.1.1. The smallest permissible cross-sections of cables and wires of electrical networks in residential buildings
7.1.36. In all buildings, the lines of the group network, laid from group, floor and apartment shields to general lighting fixtures, sockets and stationary electrical receivers, must be three-wire (phase - L, zero working - N and zero protective - PE conductors).
It is not allowed to combine zero working and zero protective conductors of different group lines.
Zero working and zero protective conductors are not allowed to be connected on shields under a common terminal.
The cross-sections of the conductors must meet the requirements of clause 7.1.45.
7.1.37. The electrical wiring in the premises should be removable: hidden - in the channels of building structures, embedded pipes; openly - in electrical skirting boards, boxes, etc.
In technical floors, undergrounds, unheated basements, attics, ventilation chambers, damp and especially damp rooms, it is recommended to carry out electrical wiring openly.
In buildings with building structures made of non-combustible materials, it is allowed to use a cable or insulated wires in a protective sheath for non-replaceable monolithic laying of group networks in the furrows of walls, partitions, ceilings, under plaster, in the floor preparation layer or in the voids of building structures. The use of non-replaceable monolithic laying of wires in panels of walls, partitions and ceilings, made during their manufacture at factories of the building industry or performed at the assembly joints of panels during the installation of buildings, is not allowed.
7.1.38. Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and they should be carried out: behind ceilings and in voids of partitions made of combustible materials in metal pipes with localization ability and in closed boxes; behind ceilings and in partitions made of non-combustible materials * - in pipes and boxes made of non-combustible materials, as well as flame-retardant cables. In this case, the possibility of replacing wires and cables must be ensured.
____________
* Under the suspended ceilings made of non-combustible materials, we mean those ceilings that are made of non-combustible materials, while other building structures located above the suspended ceilings, including intermediate floors, are also made of non-combustible materials.
7.1.39. In rooms for cooking and eating, with the exception of apartment kitchens, open laying of cables is allowed. Open laying of wires in these rooms is not allowed.
The same types of electrical wiring can be used in apartment kitchens as in living rooms and corridors.
7.1.40. In saunas, bathrooms, toilets, showers, as a rule, hidden electrical wiring should be used. Open cable routing is allowed.
In saunas, bathrooms, lavatories, shower rooms, it is not allowed to lay wires with metal sheaths, in metal pipes and metal sleeves.
In saunas for zones 3 and 4 according to GOST R 50571.12-96 “Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 703. Rooms Containing Sauna Heaters ”electrical wiring with a permissible insulation temperature of 170 ° C must be used.
7.1.41. Electrical wiring in attics must be carried out in accordance with the requirements of Sect. 2.
7.1.42. Through the basements and technical undergrounds of the building sections, it is allowed to lay power cables with a voltage of up to 1 kV, supplying electrical receivers of other sections of the building. These cables are not considered as transit cables; laying transit cables through basements and technical undergrounds of buildings is prohibited.
7.1.43. Open laying of transit cables and wires through storerooms and warehouses is not allowed.
7.1.44. The lines supplying refrigeration units of trade and public catering enterprises must be laid from the ASU or main switchboard of these enterprises.
7.1.45. The selection of the cross-section of the conductors should be carried out in accordance with the requirements of the relevant chapters of the PUE.
Single-phase two- and three-wire lines, as well as three-phase four- and five-wire lines when supplying single-phase loads, must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors.
Three-phase four- and five-wire lines when supplying three-phase symmetrical loads must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors, if the phase conductors have a cross-section of up to 16 mm 2 for copper and 25 mm 2 for aluminum, and with large cross-sections - not less than 50% of the cross section of the phase conductors.
The cross-section of the PEN conductors must be at least the cross-section of N conductors and at least 10 mm 2 for copper and 16 mm 2 for aluminum, regardless of the cross-section of the phase conductors.
The cross-section of PE conductors should be equal to the cross-section of the phase conductors with a cross-section of the latter up to 16 mm 2, 16 mm 2 with a cross-section of the phase conductors from 16 to 35 mm 2 and 50% of the cross-section of the phase conductors with large cross-sections.
The cross-section of PE conductors that are not part of the cable must be at least 2.5 mm 2 - in the presence of mechanical protection and 4 mm 2 - in its absence.
Internal electrical equipment
7.1.46. In rooms for cooking, except for kitchens of apartments, lamps with incandescent lamps installed above workplaces (stoves, tables, etc.) must have protective glass below. Luminaires with fluorescent lamps should have grilles or grids or lamp holders to prevent the lamps from falling out.
7.1.47. In bathrooms, showers and lavatories, only electrical equipment should be used that is specially designed for installation in the corresponding areas of the specified premises in accordance with GOST R 50571.11-96 “Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 701. Bathrooms and showers ", while the following requirements must be met:
Electrical equipment must have a degree of water protection not lower than:
in zone 0 - IPX7;
in zone 1 - IPX5;
in zone 2 - IPX4 (IPX5 - in public baths);
in zone 3 - IPX1 (IPX5 - in public baths);
In zone 0, electrical appliances with a voltage of up to 12 V, intended for use in a bath, can be used, and the power supply must be located outside this zone;
Only water heaters can be installed in zone 1;
In zone 2 water heaters and lamps of protection class 2 can be installed;
No junction boxes, switchgear or control devices are allowed in zones 0.1 and 2.
7.1.48. Installation of plug sockets in bathrooms, showers, soap rooms of baths, rooms containing heaters for saunas (hereinafter referred to as "saunas"), as well as in washing rooms of laundries, is not allowed, with the exception of bathrooms of apartments and hotel rooms.
In the bathrooms of apartments and hotel rooms, it is allowed to install plug sockets in zone 3 in accordance with GOST R 50571.11-96, connected to the network through isolation transformers or protected by a residual current device that responds to a differential current not exceeding 30 mA.
Any switches and sockets should be located at least 0.6 m from the doorway of the shower stall.
7.1.49. In buildings with a three-wire network (see clause 7.1.36), plug sockets with a current of at least 10 A with a protective contact must be installed.
Sockets installed in apartments, dormitory living rooms, as well as in rooms for children in childcare facilities (kindergartens, nurseries, schools, etc.) must have a protective device that automatically closes the socket when the plug is removed.
7.1.50. The minimum distance from switches, sockets and electrical installation elements to gas pipelines must be at least 0.5 m.
In rooms for children in childcare facilities (kindergartens, nurseries, schools, etc.), switches should be installed at a height of 1.8 m from the floor.
7.1.52. In saunas, bathrooms, lavatories, soap rooms, baths, steam rooms, washing rooms, laundries, etc. installation of switchgear and control devices is not allowed.
In the washbasin rooms and in zones 1 and 2 (GOST R 50571.11-96) of bathrooms and shower rooms, it is allowed to install switches operated by a cord.
7.1.53. The disconnecting devices of the lighting network of attics with elements of building structures (roof, trusses, rafters, beams, etc.) made of combustible materials must be installed outside the attic.
7.1.54. Switches for working, safety and evacuation lighting in premises intended for large numbers of people (for example, commercial premises of shops, canteens, hotel lobbies, etc.) should be accessible only to service personnel.
7.1.55. A luminaire must be installed above each building entrance.
7.1.56. House license plates and fire hydrant signs installed on the outer walls of buildings should be illuminated. Electric light sources for license plates and hydrant indicators should be powered from the building's internal lighting network, and fire hydrant indicators installed on outdoor lighting poles should be supplied from the outdoor lighting network.
7.1.57. Fire protection devices and burglar alarms, regardless of the category for the reliability of the building's power supply, must be powered from two inputs, and in their absence - two lines from one input. Switching from one line to another should be automatic.
7.1.58. Electric motors installed in the attic, distribution points, separately installed switching devices and protection devices must have a degree of protection not lower than IP44.
Electricity metering
7.1.59. In residential buildings, one single or three-phase settlement meter (with three-phase input) should be installed for each apartment.
7.1.60. Settlement meters in public buildings, in which several consumers of electricity are located, should be provided for each consumer, isolated in administrative and economic terms (ateliers, shops, workshops, warehouses, housing maintenance offices, etc.).
7.1.61. In public buildings, settlement electricity meters should be installed on the ASU (MSB) at the points of balance delineation with the power supply organization. In the presence of built-in or attached transformer substations, the power of which is fully used by the consumers of this building, settlement meters should be installed at the low voltage terminals of power transformers on combined low voltage boards, which are at the same time the ASU of the building.
ASP and metering devices of different subscribers located in the same building can be installed in one common room. By agreement with the energy supplying organization, settlement meters can be installed at one of the consumers, from which the other consumers located in this building are powered. At the same time, control meters should be installed at the inputs of the supply lines in the premises of these other consumers for settlement with the main subscriber.
7.1.62. It is recommended to install calculation meters for the general house load of residential buildings (lighting of stairwells, house management offices, courtyard lighting, etc.) in the ASU cabinets or on the main switchboard panels.
When installing apartment panels in the hallways of apartments, meters, as a rule, should be installed on these panels; installation of meters on floor panels is allowed.
7.1.64. For safe replacement of a meter directly connected to the network, a switching device must be provided in front of each meter to remove voltage from all phases connected to the meter.
Disconnecting devices for removing voltage from settlement meters located in apartments should be located outside the apartment.
7.1.65. After the meter connected directly to the network, a protection device must be installed. If after the counter there are several lines equipped with protection devices, the installation of a general protection device is not required.
Protective security measures
7.1.67. Grounding and protective measures for the safety of electrical installations of buildings must be carried out in accordance with the requirements of Ch. 1.7 and additional requirements given in this section.
7.1.68. In all rooms, it is necessary to connect open conductive parts of general lighting fixtures and stationary electrical receivers (electric stoves, boilers, household air conditioners, electric towels, etc.) to the zero protective conductor.
7.1.69. In the premises of buildings, metal cases of single-phase portable electrical appliances and desktop office equipment of class I in accordance with GOST 12.2.007.0-75 “SSBT. Electrical products. General safety requirements "must be connected to the protective conductors of a three-wire group line (see clause 7.1.36).
Metal frames of partitions, doors and frames used for laying cables must be connected to protective conductors.
7.1.70. In rooms without increased danger, it is allowed to use pendant lamps that are not equipped with clamps for connecting protective conductors, provided that the hook for their suspension is insulated. The requirements of this clause do not cancel the requirements of clause 7.1.36 and do not constitute a basis for two-wire wiring.
7.1.71. To protect the group lines supplying sockets for portable electrical devices, it is recommended to provide residual current devices (U 30).
7.1.72. If the overcurrent protection device (circuit breaker, fuse) does not provide an automatic shutdown time of 0.4 s at a rated voltage of 220 V due to low short-circuit currents and the installation (apartment) is not covered by the equipotential bonding system, the installation of an RCD is mandatory.
7.1.73. When installing an RCD, the selectivity requirements must be consistently met. With two- and multi-stage circuits, the RCD located closer to the power source must have a setting and the response time at least 3 times longer than that of an RCD located closer to the consumer.
7.1.74. In the area of \u200b\u200bthe RCD, the neutral working conductor should not have connections with grounded elements and a zero protective conductor.
7.1.75. In all cases of application, the RCD must ensure reliable switching of load circuits, taking into account possible overloads.
It is not allowed to use RCDs in group lines that do not have overcurrent protection, without an additional device providing this protection.
When using RCDs that do not have overcurrent protection, it is necessary to check them in overcurrent modes, taking into account the protective characteristics of the upstream device that provides overcurrent protection.
7.1.77. In residential buildings, it is not allowed to use RCDs that automatically disconnect the consumer from the network when the network voltage disappears or is impermissible. In this case, the RCD must remain operational for at least 5 s when the voltage drops to 50% of the nominal.
7.1.78. In buildings, type "A" RCDs can be used, which react to both alternating and pulsating fault currents, or "AC", which react only to alternating leakage currents.
The source of the pulsating current is, for example, washing machines with speed controllers, adjustable light sources, televisions, VCRs, personal computers, etc.
7.1.79. In group networks supplying plug sockets, an RCD with a rated operating current of no more than 30 mA should be used.
It is allowed to connect several group lines to one RCD through separate circuit breakers (fuses).
Installation of RCDs in lines supplying stationary equipment and lamps, as well as in general lighting networks, is usually not required.
7.1.81. Installation of an RCD is prohibited for electrical receivers, the disconnection of which can lead to situations that are dangerous for consumers (shutdown of the fire alarm, etc.).
7.1.82. It is mandatory to install an RCD with a rated operating current of no more than 30 mA for group lines supplying outlet networks located outdoors and in rooms of especially dangerous and with increased danger, for example, in zone 3 of bathrooms and shower rooms of apartments and hotel rooms.
7.1.83. The total leakage current of the network, taking into account the connected stationary and portable electrical receivers in normal operation, should not exceed 1/3 of the rated current of the RCD. In the absence of data, the leakage current of electrical receivers should be taken at the rate of 0.4 mA per 1 A of the load current, and the leakage current of the network - at the rate of 10 μA per 1 m of the length of the phase conductor.
7.1.84. To increase the level of protection against fire in case of short circuits to grounded parts, when the current value is insufficient to trigger the overcurrent protection, at the input to an apartment, individual house, etc. it is recommended to install an RCD with a tripping current up to 300 mA.
7.1.85. For residential buildings, if the requirements of clause 7.1.83 are met, the RCD functions according to clauses 7.1.79 and 7.1.84 can be performed by one device with an operating current not exceeding 30 mA.
7.1.86. If the RCD is intended for protection against electric shock and fire, or only for protection against fire, then it must disconnect both phase and neutral working conductors; overcurrent protection in the neutral working conductor is not required.
7.1.87. At the entrance to the building, a potential equalization system must be performed by combining the following conductive parts:
Main (trunk) protective conductor;
Main (trunk) grounding conductor or main grounding clamp;
Steel pipes for building communications and between buildings;
Metal parts of building structures, lightning protection, central heating, ventilation and air conditioning systems. Such conductive parts must be interconnected at the entrance to the building.
7.1.88. All exposed conductive parts of stationary electrical installations, third-party conductive parts and zero protective conductors of all electrical equipment (including sockets) must be connected to the additional potential equalization system.
For bathrooms and shower rooms, an additional potential equalization system is mandatory and must include, among other things, the connection of third-party conductive parts that extend outside the premises. If there is no electrical equipment with zero protective conductors connected to the potential equalization system, then the potential equalization system should be connected to the PE bus (terminal) at the input. Heating elements embedded in the floor must be covered with a grounded metal mesh or grounded metal sheath connected to an equipotential bonding system. As an additional protection for heating elements, it is recommended to use an RCD for a current up to 30 mA.
It is not allowed to use local equipotential bonding systems for saunas, bathrooms and showers.
|
|
||||||
| PUE
Section 7. ELECTRICAL EQUIPMENT OF SPECIAL INSTALLATIONS Chapter 7.1 ELECTRICAL INSTALLATIONS OF RESIDENTIAL, PUBLIC, ADMINISTRATIVE AND DOMESTIC BUILDINGS |
||||||
|
| Ministry of Fuel and Energy of the Russian Federation | Introduced: | 01.01.2003 | |||
|
|
| Designed by: | JSC "VNIPI Tyazhpromelektroproekt" | |||
|
| Topics : | Electrical installations of residential, public, administrative and household buildings. Electrical installations for entertainment companies, clubs and sports facilities. Electrical installations in. Electrical installations in fire hazardous areas. Electrothermal installations. Electric welding installations. Peat electrical installations. Electrolysis plants and galvanic coating plants. | ||||
|
|
| Terms: | Input device; Main switchboard; Distribution point; Group shield; Apartment flap; Floor switchboard; Switchboard room; Power supply network; Distribution network; Group network; Scene; Stage; Manege; Stage rise; Staged; Technical hardware rooms; Explosion; Flash; Smoldering; Electrical sparking; Intrinsically safe electrical circuit; Flash point; Ignition temperature; Autoignition temperature; Smoldering temperature; Highly flammable liquid; Flammable liquid; Light gas; Heavy gas; Liquefied gas; Explosive mixture; Upper and lower concentration limits of ignition; Premises; Outdoor installation; ; ; General purpose electrical equipment; Safe experimental maximum clearance; Zones class P-I; Class P-II zones; Class P-IIa zones; Class P-III zones; Electrothermal installation; Electrothermal equipment; Furnace transformer or converter substation; Furnace power transformer; Furnace converter transformer; Stove switch; Electric welding installation; Welding current source; Welding chain; Welding station of an electric welding installation; Single-station or multi-station welding current source; Autonomous electric welding installations; Plants for electrolysis and electroplating; Rectifier unit; Parametric rectifier unit; Semiconductor rectifier; Converter substation of electrolysis plants; Electrolysis bath or electrolyzer; Electrolysis bath series; Electrolysis hall; Building, station or electrolysis workshop; Electroplating workshop
|
|||
|
|
| Notes: | Applies to special electrical installations | |||
RULES FOR THE DEVICE OF ELECTRICAL INSTALLATIONS
PUE
ELECTRICAL EQUIPMENT OF SPECIAL PLANTS
Electrical installations of residential, public, administrative and household buildings
(SIXTH EDITION, revised and expanded, as amended)INCLUDED all changes made in the period from August 31, 1985 to December 30, 1997 and agreed in the necessary part with the Gosstroy of Russia and the Gosgortechnadzor of Russia.
Added changes from 07/14/98.
Section 6 and Chapters 7.1, 7.2 are revised in the seventh edition (1999)
Chapters 1.1, 1.2, 1.7, 1.9, 7.5, 7.6, 7.10 are revised in the seventh edition (2002)
APPROVED by the Ministry of Energy of the Russian Federation Order of July 8, 2002 No. 204
Effective from January 1, 2003.
TABLE OF CONTENTS
Section 1.Section 2.
Section 3.
Section 4.
Section 5.
Section 6.
Section 7. ELECTRICAL EQUIPMENT OF SPECIAL PLANTS
Chapter 7.1. Electrical installations of residential, public, administrative and household buildings
Chapter 7.2.
Chapter 7.3.
Chapter 7.4.
Chapter 7.5.
Application area
Definitions
General requirements
Installations of direct and indirect arc furnaces and resistance arc furnaces
Induction and dielectric heating installations
Installations of direct and indirect resistance furnaces
Electron beam installations
Ionic and laser systems
Application area
Definitions
General requirements
Requirements for premises for welding installations and welding stations
Installations for electric fusion welding (cutting, surfacing)
Electrical pressure welding systems
Chapter 7.10.
Application area
Definitions. Composition of installations
General requirements
Plants for electrolysis of water and aqueous solutions
Electrolysis plants for hydrogen production (hydrogen stations)
Chlorine electrolysis plants
Magnesium electrolysis plants
Aluminum electrolysis plants
Plants for electrolytic aluminum refining
Electrolysis plants for ferroalloy production
Electrolysis plants for nickel-cobalt production
Copper electrolysis plants
Plants for electroplating
Section 7 ELECTRICAL EQUIPMENT OF SPECIAL INSTALLATIONS
Chapters 7.1, 7.2 revised in the seventh edition (1999)Chapters 7.5, 7.6, 7.10 revised in the seventh edition (2002)
Chapter 7.1 ELECTRICAL INSTALLATIONS OF RESIDENTIAL, PUBLIC, ADMINISTRATIVE AND DOMESTIC BUILDINGS *
Application area. Definitions
7.1.1. This chapter of the Rules applies to electrical installations: residential buildings listed in "; public buildings listed in (except for buildings and premises listed in Chapter 7.2); administrative and household buildings listed in; additional requirements may be imposed on electrical installations of unique and other special buildings not included in the above list.Hereinafter, unless specified, the word “buildings” refers to all types of buildings covered by this chapter.
The requirements of this chapter do not apply to special electrical installations in medical institutions, organizations and institutions of science and scientific services, to systems and communications, as well as to electrical installations, which, by their nature, should be attributed to electrical installations of industrial enterprises (workshops, boiler rooms, heating points , pumping stations, laundry factories, dry cleaning factories, etc.).
* The requirements of this chapter are interrelated. It should be borne in mind that partial fulfillment of a set of requirements for electrical installations of buildings can lead to a decrease in the level of electrical safety.7.1.2. Electrical installations of buildings, in addition to the requirements of this chapter, must meet the requirements of chapters of section. 1-6 PUE to the extent that they are not changed by this chapter.
7.1.3. Input device (VU) - a set of structures, apparatus and devices installed at the input of the supply line to the building or to its isolated part.
The input device, which also includes devices and devices of the outgoing lines, is called the input-distribution device (ASU).
7.1.4. Main switchboard (MSB) - a distribution board through which the entire building or its separate part is supplied with electricity. The role of the main switchboard can be performed by an ASU or a low voltage board of a substation.
7.1.5. Distribution point (RP) - a device in which protection devices and switching devices (or only protection devices) are installed for individual electrical receivers or their groups (electric motors, group panels).
7.1.6. Group flap - a device in which protection devices and switching devices (or only protection devices) are installed for individual groups of lamps, plug sockets and stationary electrical receivers.
7.1.7. Apartment flap - a group panel installed in the apartment and designed to connect the mains supplying lamps, sockets and stationary electrical receivers of the apartment.
7.1.8. Floor switchboard- a shield installed on the floors of residential buildings and designed to power apartments or apartment panels.
7.1.9. Switchboard room - a room accessible only for qualified service personnel, in which VU, VRU, main switchgear and other distribution devices are installed.
7.1.10. Supply network - a network from a substation switchgear or a branch from overhead power lines to VU, VRU, main switchboard.
7.1.11. Distribution network - a network from VU, VRU, main switchboard to distribution points and panels.
7.1.12. Group network - a network from shields and distribution points to lamps, plug sockets and other electrical receivers.
General requirements.
7.1.13. The power supply of electrical consumers should be carried out from a 380/220 V network with TN-S or TN-C-S system.When reconstructing residential and public buildings with a voltage of 220/127 V or 3 x 220 V, it is necessary to provide for the transfer of the network to a voltage of 380/220 V with a TN-S or TN-C-S grounding system.
7.1.14. External power supply of buildings must meet the requirements of Chapter 1.2.
7.1.15. In dormitories of various institutions, in schools and other educational institutions, etc. the construction of built-in and attached substations is not allowed.
In residential buildings, in exceptional cases, it is allowed to place built-in and attached substations using dry transformers in agreement with the state supervision authorities, while the sanitary requirements for limiting the level of noise and vibration must be fully met in accordance with the current standards.
The device and placement of built-in, attached and free-standing substations should be carried out in accordance with the requirements of chapters of Sect. 4.
7.1.16. It is recommended to supply power and lighting electrical receivers from the same transformers.
7.1.17. The location and layout of transformer substations should provide for the possibility of round-the-clock unhindered access to them by the personnel of the power supply organization.
7.1.18. Power supply of safety lighting and evacuation lighting must be carried out in accordance with the requirements of Ch. 6.1 and 6.2 as well.
7.1.19. If there are elevators in the building, which are also intended for the transportation of fire brigades, their power supply must be provided in accordance with the requirements of Ch. 7.8.
7.1.20. The electrical networks of buildings should be designed to power advertising lighting, showcases, facades, illumination, outdoor, fire-prevention devices, dispatching systems, local networks, fire hydrants, safety signs, bells and others, lights, light barriers, etc., in accordance with the assignment for design.
7.1.21. When powering single-phase consumers of buildings from a multiphase distribution network, it is allowed for different groups of single-phase consumers to have common N and PE conductors (five-wire network) laid directly from the ASP, the combination of N and PE conductors (four-wire network with a PEN conductor) is not allowed.
When supplying single-phase consumers from a multiphase supply network with branches from overhead lines, when the PEN conductor of the overhead line is common for groups of single-phase consumers powered from different phases, it is recommended to provide a protective shutdown of consumers when the voltage exceeds the allowable voltage arising from load asymmetry in case of PEN conductor. Disconnection should be carried out at the entrance to the building, for example, by acting on the shunt release of the input circuit breaker by means of an overvoltage relay, while both phase (L) and zero working (N) conductors should be disconnected.
When choosing devices and devices installed at the input, preference, other things being equal, should be given to devices and devices that remain operational when the voltage is exceeded above the permissible voltage arising from load asymmetry when a PEN or N conductor is broken, while their switching and other performance may not be met.
In all cases, it is forbidden to have switching contact and non-contact elements in the PE and PEN conductor circuits.
Connections that can be disassembled with a tool are acceptable, as well as connectors specially designed for this purpose.
Input devices, switchboards, distribution points, group boxes
7.1.22. At the entrance to the building, a VU or ASU must be installed. One or more VU or ASU can be installed in the building.If there are several economically isolated consumers in the building, it is recommended that each of them install an independent VU or ASU.
Power supply to consumers located in other buildings is also allowed from the ASP, provided that these consumers are functionally connected.
With branches from overhead lines with a design current of up to 25 A, the VU or VU at the inputs to the building may not be installed if the distance from the branch to the group panel, which in this case performs the functions of the VU, is not more than 3 m. This section of the network must be performed with a flexible copper cable with a conductor cross-section of at least 4 mm², flame retardant, laid in a steel pipe, while the requirements for ensuring a reliable contact connection with branch wires must be met.
For air inlet, surge suppressors must be installed.
7.1.23. Before entering the buildings, it is not allowed to install additional cable boxes to separate the service sector of external supply networks and networks inside the building. Such a division must be performed in the ASU or the main switchboard.
7.1.24. VU, VRU, main switchboard must have protection devices at all inputs of supply lines and on all outgoing lines.
7.1.25. Control devices should be installed at the input of the supply lines to the VU, VRU, main switchboard. On outgoing lines, control devices can be installed either on each line, or be common to several lines.
The circuit breaker should be regarded as a protection and control device.
7.1.26. Control devices, regardless of their presence at the beginning of the supply line, must be installed at the inputs of supply lines in retail premises, utilities, administrative premises, etc., as well as in the premises of consumers, isolated in administrative terms.
7.1.27. The floor panel should be installed at a distance of no more than 3 m along the length of the wiring from the supply riser, taking into account the requirements of Ch. 3.1.
7.1.28. VU, VRU, main switchboard, as a rule, should be installed in switchboard rooms accessible only to service personnel. In areas prone to flooding, they should be installed above the flood level.
VU, VRU, main switchboard can be located in rooms allocated in operated dry basements, provided that these rooms are accessible to service personnel and separated from other rooms by partitions with a limit of at least 0.75 hours.
When placing VU, ASU, main switchboard, distribution points and group boards outside the switchboard rooms, they should be installed in convenient and accessible places for maintenance, in cabinets with a shell protection degree of at least IP31.
The distance from pipelines (water supply, heating, sewerage, internal drains), gas pipelines and gas meters to the installation site must be at least 1 m.
7.1.29. Switchboard rooms, as well as VU, VRU, main switchboard, are not allowed to be located under toilets, bathrooms, showers, kitchens (except kitchens of apartments), sinks, washing and steam rooms of baths and other rooms associated with wet technological processes, except for cases when special measures have been taken to ensure reliable waterproofing to prevent moisture from entering the premises where the switchgear is installed.
It is not recommended to lay pipelines (water supply, heating) through switch rooms.
Pipelines (water supply, heating), ventilation and other ducts laid through the switchboard rooms should not have branches within the room (except for a branch to the heating device of the switchboard room itself), as well as hatches, valves, flanges, valves, etc.
Laying through these rooms gas and pipelines with flammable liquids, sewerage and internal drains are not allowed.
The doors of the electrical room must open outward.
7.1.30. The rooms in which the ASU, the main switchboard are installed, must have natural ventilation, electric lighting. The room temperature should not be lower than + 5 ° С.
7.1.31. Electrical circuits within VU, ASU, main switchboard, distribution points, group shields should be carried out with wires with copper conductors.
Electrical wiring and cable lines
7.1.32. Internal wiring should be carried out taking into account the following:1. Electrical installations of different organizations, separated in administrative and economic terms, located in the same building, can be connected by branches to a common supply line or powered by separate lines from the ASU or main switchboard.
2. It is allowed to connect several risers to one line. On the branches to each riser supplying apartments in residential buildings with more than 5 floors, a control device should be installed, combined with a protection device.
3. In residential buildings, lamps for staircases, lobbies, halls, floor corridors and other indoor premises outside apartments should be powered by independent lines from the ASU or separate group shields powered by the ASU. Connecting these lamps to floor and apartment shields is not allowed.
4. For staircases and corridors with natural light, it is recommended to provide automatic control of electric lighting, depending on that created by natural light.
5. It is recommended to supply power to non-residential electrical installations by separate lines.
7.1.33. Power supply networks from substations to VU, ASU, MSB must be protected from short-circuit currents.
7.1.34. In buildings, use copper cables and wires *.
Supply and distribution networks, as a rule, must be carried out with cables and wires with aluminum conductors, if their design cross-section is 16 mm² or more.
Power supply of individual electrical receivers related to the engineering equipment of buildings (pumps, fans, heaters, air conditioning units, etc.) can be carried out with wires or cables with aluminum conductors with a cross section of at least 2.5 mm².
In museums, art galleries, exhibition premises, it is allowed to use lighting bus ducts with a degree of protection IP20, in which branching devices to luminaires have a busbar trunking inside the duct at the time of switching, and bus ducts with a degree of protection IP44, in which branches to the luminaires are made using plug connectors ensuring the break of the branch circuit until the plug is removed from the socket.
In these rooms, lighting bus ducts must be powered from distribution points by independent lines.
In residential buildings, the cross-sections of copper conductors must correspond to the calculated values, but not less than those indicated in table 7.1.1.
* Until 2001, according to the existing construction reserve, it is allowed to use wires and cables with aluminum conductors.7.1.35. In residential buildings, the laying of vertical sections of the distribution network inside apartments is not allowed.
It is forbidden to lay wires and cables from the floor panel in a common pipe, common duct or channel supplying the lines of different apartments.
A flame-retardant laying in a common pipe, common box or channel of building structures made of non-combustible materials, wires and cables of supply lines of apartments, together with wires and cables of group lines of working lighting of staircases, floor corridors and other indoor premises, is allowed.
Table 7.1.1.
The smallest permissible cross-sections of cables and wires of electrical networks in residential buildings
7.1.36. In all buildings, the lines of the group network, laid from group, floor and apartment shields to general lighting fixtures, plug sockets and stationary electrical receivers, must be three-wire (phase - L, zero working - N and zero protective - PE conductors).
It is not allowed to combine zero working and zero protective conductors of different group lines.
Zero working and zero protective conductors are not allowed to be connected on shields under a common terminal.
The cross-sections of the conductors must meet the requirements of clause 7.1.45.
7.1.37. The electrical wiring in the premises should be removable: hidden - in the channels of building structures, embedded pipes; openly - in electrical skirting boards, boxes, etc.
In technical floors, undergrounds, unheated basements, attics, ventilation chambers, damp and especially damp rooms, it is recommended to carry out electrical wiring openly.
In buildings with building structures made of non-combustible materials, permanently monolithic laying of group networks in the furrows of walls, partitions, ceilings, under plaster, in the floor preparation layer or in the voids of building structures is allowed, carried out with a cable or insulated wires in a protective sheath. The use of non-replaceable monolithic laying of wires in panels of walls, partitions and ceilings, made during their manufacture at factories of the building industry or performed at the assembly joints of panels during the installation of buildings, is not allowed.
7.1.38. Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and they should be carried out: behind ceilings and in voids of partitions made of combustible materials in metal pipes with localization ability and in closed boxes; behind ceilings and in partitions made of non-combustible materials * - in pipes and boxes made of non-combustible materials, as well as flame-retardant cables. In this case, the possibility of replacing wires and cables must be ensured.
* Under the suspended ceilings made of non-combustible materials, we mean those ceilings that are made of non-combustible materials, while other building structures located above the suspended ceilings, including intermediate floors, are also made of non-combustible materials.7.1.39. In rooms for cooking and eating, with the exception of apartment kitchens, open laying of cables is allowed. Open laying of wires in these rooms is not allowed.
The same types of electrical wiring can be used in apartment kitchens as in living rooms and corridors.
7.1.40. In bathrooms, toilets, showers, as a rule, hidden electrical wiring should be used. Open cable routing is allowed.
In saunas, bathrooms, lavatories, shower rooms, it is not allowed to lay wires with metal sheaths, in metal pipes and metal sleeves.
In saunas for zones 3 and 4 according to R 50571.12-96 “Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 703. Rooms Containing Sauna Heaters ”electrical wiring with a permissible insulation temperature of 170 ° C must be used.
7.1.41. Electrical wiring in attics must be carried out in accordance with the requirements of Sect. 2.
7.1.42. Through the basements and technical undergrounds of the building sections, it is allowed to lay power cables with a voltage of up to 1 kV, supplying electrical receivers of other sections of the building. These cables are not considered as transit cables; laying transit cables through basements and technical undergrounds of buildings is prohibited.
7.1.43. Open laying of transit cables and wires through storerooms and warehouses is not allowed.
7.1.44. The lines supplying refrigeration units and public catering must be laid from the ASU or main switchboard of these enterprises.
7.1.45. The selection of the cross-section of the conductors should be carried out in accordance with the requirements of the relevant chapters of the PUE.
Single-phase two- and three-wire lines, as well as three-phase four- and five-wire lines when supplying single-phase loads, must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors.
Three-phase four- and five-wire lines when supplying three-phase symmetrical loads must have a cross-section of zero working (N) conductors equal to the cross-section of the phase conductors, if the phase conductors have a cross-section of up to 16 mm² for copper and 25 mm² for aluminum, and with large cross-sections - at least 50 % of the section of the phase conductors.
The cross-section of PEN conductors must be at least the cross-section of N conductors and at least 10 mm² for copper and 16 mm² for aluminum, regardless of the cross-section of the phase conductors.
The cross-section of PE conductors should be equal to the cross-section of the phase conductors with a cross-section of the latter up to 16 mm², 16 mm² with a cross-section of the phase conductors from 16 to 35 mm² and 50% of the cross-section of the phase conductors with large cross-sections.
The cross-section of PE conductors that are not part of the cable must be at least 2.5 mm² - in the presence of mechanical protection and 4 mm² - in its absence.
Internal
7.1.46. In rooms for food preparation, except for kitchens of apartments, lamps with incandescent lamps installed above workplaces (stoves, tables, etc.) must have a protective glass below. Luminaires with fluorescent lamps must have grilles or grids or lamp holders to prevent the lamps from falling out.7.1.47. In bathrooms, showers and lavatories, only electrical equipment should be used that is specifically designed for installation in the corresponding zones of the specified premises, while the following requirements must be met:
Electrical equipment must have water content not lower than:
in zone 0 - IPX7;
in zone 1 - IPX5;
in zone 2 - IPX4 (IPX5 - in public baths);
in zone 3 - IPX1 (IPX5 - in public baths);
In zone 0, electrical appliances with a voltage of up to 12 V, intended for use in a bath, can be used, and the power supply must be located outside this zone;
- only water heaters can be installed in zone 1;
- in zone 2, water heaters and lamps of protection class 2 can be installed;
- installation of junction boxes, switchgear and control devices is not allowed in zones 0,1 and 2.
7.1.48. Installation of plug sockets in bathrooms, showers, soap rooms of baths, rooms containing heaters for saunas (hereinafter referred to as "saunas"), as well as in washing rooms of laundries, is not allowed, with the exception of bathrooms of apartments and hotel rooms.
In the bathrooms of apartments and hotel rooms, it is allowed to install plug sockets in zone 3 in accordance with GOST R 50571.11-96, connected to the network through isolation transformers or protected by a residual current device that responds to a differential current not exceeding 30 mA.
Any switches and sockets should be located at least 0.6 m from the doorway of the shower stall.
7.1.49. In buildings with a three-wire network (see clause 7.1.36), plug sockets with a current of at least 10 A with a protective contact must be installed.
Sockets installed in apartments, dormitory living rooms, as well as in rooms for children in childcare facilities (kindergartens, nurseries, schools, etc.) must have a protective device that automatically closes the socket when the plug is removed.
7.1.50. The minimum distance from switches, sockets and electrical installation elements to gas pipelines must be at least 0.5 m.
7.1.51. It is recommended to install the switches on the wall from the side of the door handle at a height of up to 1 m; it is allowed to install them under the ceiling with control by means of a cord.
In rooms for children in child care (kindergartens, nurseries, schools, etc.), switches should be installed at a height of 1.8 m from the floor.
7.1.52. In saunas, bathrooms, lavatories, soap rooms of baths, steam rooms, washing rooms, laundries, etc. installation of switchgear and control devices is not allowed.
In the washbasin rooms and in zones 1 and 2 (GOST R 50571.11-96) of bathrooms and shower rooms, it is allowed to install switches operated by a cord.
7.1.53. The disconnecting devices of the lighting network of attics that have elements of building structures (roof, trusses, rafters, beams, etc.) made of combustible materials must be installed outside the attic.
7.1.54. Switches for working, safety and evacuation lighting in premises intended for large numbers of people (for example, commercial premises of shops, canteens, hotel lobbies, etc.) should be accessible only to service personnel.
7.1.55. A luminaire must be installed above each entrance to the building.
7.1.56. House license plates and fire hydrant signs installed on the outer walls of buildings should be illuminated. Electric light sources for license plates and hydrant indicators should be powered from the building's internal lighting network, and fire hydrant indicators installed on outdoor lighting poles should be supplied from the outdoor lighting network.
7.1.57. Fire-fighting devices and a security one, regardless of the category of the building's power supply reliability, must be powered from two inputs, and in their absence - two lines from one input. Switching from one line to another should be automatic.
7.1.58. Electric motors installed in the attic, distribution points, separately installed switching devices and protection devices must have a degree of protection not lower than IP44.
Electricity metering
7.1.59. In residential buildings, one single or three-phase settlement meter (with three-phase input) should be installed for each apartment.7.1.60. Settlement meters in public buildings, in which several consumers of electricity are located, should be provided for each consumer, isolated in administrative and economic terms (ateliers, shops, workshops, warehouses, housing maintenance offices, etc.).
7.1.61. In public buildings, settlement electricity meters should be installed on the ASU (MSB) at the points of balance delineation with the power supply organization. In the presence of built-in or attached transformer substations, the power of which is fully used by the consumers of this building, settlement meters should be installed at the low voltage terminals of power transformers on combined low voltage boards, which are at the same time the ASU of the building.
ASP and metering devices of different subscribers located in the same building can be installed in one common room. By agreement with the energy supplying organization, settlement meters can be installed at one of the consumers, from which the other consumers located in this building are powered. At the same time, control meters should be installed at the inputs of the supply lines in the premises of these other consumers for settlement with the main subscriber.
7.1.62. It is recommended to install calculation meters for the general house load of residential buildings (lighting of stairwells, house management offices, courtyard lighting, etc.) in the ASU cabinets or on the main switchboard panels.
7.1.63. Calculated apartment meters are recommended to be placed together with protection devices (circuit breakers, fuses).
When installing apartment panels in the hallways of apartments, meters, as a rule, should be installed on these panels; installation of meters on floor panels is allowed.
7.1.64. For safe replacement of a meter directly connected to the network, a switching device must be provided in front of each meter to remove voltage from all phases connected to the meter.
Disconnecting devices for removing voltage from settlement meters located in apartments should be located outside the apartment.
7.1.65. After the meter connected directly to the network, a protection device must be installed. If after the counter there are several lines equipped with protection devices, the installation of a general protection device is not required.
7.1.66. It is recommended to equip residential buildings with remote meter reading systems.
Protective security measures
7.1.67. Grounding and protective measures for the safety of electrical installations of buildings must be carried out in accordance with the requirements of Ch. 1.7 and additional requirements given in this section.7.1.68. In all rooms, it is necessary to connect open conductive parts of general lighting fixtures and stationary electrical receivers (electric stoves, boilers, household air conditioners, electric towels, etc.) to the zero protective conductor.
7.1.69. In premises of buildings, metal cases of single-phase portable electrical appliances and desktop office equipment of class I must be connected to the protective conductors of a three-wire group line (see clause 7.1.36).
Metal frames of partitions, doors and frames used for laying cables must be connected to protective conductors.
7.1.70. In rooms without increased danger, it is allowed to use pendant lamps that are not equipped with clamps for connecting protective conductors, provided that the hook for their suspension is insulated. The requirements of this clause do not cancel the requirements of clause 7.1.36 and do not constitute a basis for two-wire wiring.
7.1.71. To protect the group lines supplying sockets for portable electrical devices, it is recommended to provide residual current devices (U 30).
7.1.72. If the overcurrent protection device (circuit breaker, fuse) does not provide an automatic shutdown time of 0.4 s at a rated voltage of 220 V due to low short-circuit currents and the installation (apartment) is not covered by the equipotential bonding system, the installation of an RCD is mandatory.
7.1.73. When installing an RCD, the selectivity requirements must be consistently met. With two- and multi-stage circuits, the RCD located closer to the power source must have a setting and the response time at least 3 times longer than that of an RCD located closer to the consumer.
7.1.74. In the area of \u200b\u200bthe RCD, the neutral working conductor should not have connections with grounded elements and a zero protective conductor.
7.1.75. In all cases of application, the RCD must ensure reliable switching of load circuits, taking into account possible overloads.
7.1.76. It is recommended to use an RCD, which is a single device with a circuit breaker providing overcurrent protection.
It is not allowed to use RCDs in group lines that do not have overcurrent protection, without an additional device providing this protection.
When using RCDs that do not have overcurrent protection, it is necessary to check them in overcurrent modes, taking into account the protective characteristics of the upstream device that provides overcurrent protection.
7.1.77. In residential buildings, it is not allowed to use RCDs that automatically disconnect the consumer from the network when the network voltage disappears or is impermissible. In this case, the RCD must remain operational for at least 5 s when the voltage drops to 50% of the nominal.
7.1.78. In buildings, type "A" RCDs can be used, which react to both alternating and pulsating fault currents, or "AC", which react only to alternating leakage currents.
The source of the pulsating current is, for example, washing machines with speed controllers, adjustable light sources, televisions, personal computers, etc.
7.1.79. In group networks supplying plug sockets, an RCD with a rated operating current of no more than 30 mA should be used.
It is allowed to connect several group lines to one RCD through separate circuit breakers (fuses).
Installation of RCDs in lines supplying stationary equipment and lamps, as well as in general lighting networks, is usually not required.
7.1.80. In residential buildings, it is recommended to install RCDs on apartment shields, they can be installed on floor shields.
7.1.81. The installation of an RCD is prohibited for electrical receivers, the disconnection of which can lead to situations dangerous for consumers (disconnection, etc.).
7.1.82. It is mandatory to install an RCD with a rated operating current of no more than 30 mA for group lines supplying outlet networks located outdoors and in rooms of especially dangerous and with increased danger, for example, in zone 3 of bathrooms and shower rooms of apartments and hotel rooms.
7.1.83. The total leakage current of the network, taking into account the connected stationary and portable electrical receivers in normal operation, should not exceed 1/3 of the rated current of the RCD. In the absence of data, the leakage current of electrical receivers should be taken at the rate of 0.4 mA per 1 A of the load current, and the leakage current of the network - at the rate of 10 μA per 1 m of the length of the phase conductor.
7.1.84. To increase the level of protection against fire in case of short circuits to grounded parts, when the current value is insufficient to trigger the overcurrent protection, at the input to an apartment, individual house, etc. it is recommended to install an RCD with a tripping current up to 300 mA.
7.1.85. For residential buildings, if the requirements of clause 7.1.83 are met, the RCD functions according to clauses 7.1.79 and 7.1.84 can be performed by one device with an operating current not exceeding 30 mA.
7.1.86. If the RCD is intended for protection against electric shock and fire, or only for protection against fire, then it must disconnect both phase and neutral working conductors; overcurrent protection in the neutral working conductor is not required.
7.1.87. At the entrance to the building, a potential equalization system must be performed by combining the following conductive parts:
Main (trunk) protective conductor;
- main (trunk) grounding conductor or main grounding clamp;
- steel pipes for building communications and between buildings;
- metal parts of building structures, central heating and air conditioning systems. Such conductive parts must be interconnected at the entrance to the building.
It is recommended that additional equipotential bonding systems be repeated in the course of power transmission.
7.1.88. All exposed conductive parts of stationary electrical installations, third-party conductive parts and zero protective conductors of all electrical equipment (including sockets) must be connected to the additional potential equalization system.
For bathrooms and shower rooms, an additional potential equalization system is mandatory and must include, among other things, the connection of third-party conductive parts that extend outside the premises. If there is no electrical equipment with zero protective conductors connected to the potential equalization system, then the potential equalization system should be connected to the PE bus (terminal) at the input. Heating elements embedded in the floor must be covered with a grounded metal mesh or grounded metal sheath connected to an equipotential bonding system. As an additional protection for heating elements, it is recommended to use an RCD for a current up to 30 mA.
It is not allowed to use local equipotential bonding systems for saunas, bathrooms and showers.
Material presented on the page NOT AN OFFICIAL EDITION
