Chapter 4.1. SWITCH DEVICES WITH VOLTAGE up to 1 kV AC and up to 1.5 kV DC Application area Question. Which RUs are covered by this chapter of the Rules? Answer. Applies to switchgear and NKU voltages up to 1 kV AC and up to 1.5 kV

Chapter 4.2. SWITCH DEVICES AND SUBSTATIONS WITH VOLTAGES ABOVE 1 kV Scope, definitions Question. Which switchgear and transformer substations (TS) are covered by this chapter of the Rules? Answer. Applies to stationary switchgear and substation alternating current

Open distribution devices Question. How should connections of flexible wires be made in spans, in loops at supports, connections in spans and to hardware terminals? Answer. Must be performed by crimping using connecting clamps, and connections in loops

Intrashop switchgears and transformer substations Question. Where can in-shop switchgear and substations be located? Answer. Switchgear and substations with oil-filled equipment can be located on the first and second floors in the main and auxiliary rooms

Input devices, distribution boards, distribution points, group panels Question. What should be installed at the entrance to the building? Answer. A VU or ASU must be installed. One or more VU or ASU (7.1.22) may be installed in a building. Question. What

Switchgears, transformer and converter substations Question. Is it allowed to build directly in explosive zones switchgear with voltages up to 1 kV and higher, transformer substations and converter substations with general-purpose electrical equipment (without means

Switchgears, transformer and distribution substations Question. Is it allowed to install switchgear with voltages up to 1 kV and higher in fire hazardous areas? Answer. Their installation in fire hazardous areas of any class is not recommended. If necessary, install the switchgear

1.8.25. Complete switchgear for indoor and outdoor installation (KRU and KRUN) Question 113. What is the scope and standards for measuring the insulation resistance of KRU and KRUN? Answer. The insulation resistance is measured: primary circuits. The measurement is carried out with a megohmmeter on

Chapter 4.1. SWITCH DEVICES WITH VOLTAGE UP TO 1 KV AC AND UP TO 1.5 KV DC Scope Question 1. Which switchgears are covered by this chapter of the Rules? Answer. Applies to distribution devices

Chapter 4.2. SWITCHGEARS AND SUBSTATIONS WITH VOLTAGES ABOVE 1 KV Scope, definitions Question 20. Which switchgears and transformer substations (TS) are covered by this chapter of the Rules? Answer. Spreads on

Open distribution devices Question 53. How should flexible wire connections be made in spans, in loops at supports, connections in the span and to hardware terminals? Answer. Must be performed by crimping using connecting clamps, and connections in loops

In-shop switchgears and transformer substations Question 98. Where can in-shop switchgear and substations with oil-filled equipment be located? Answer. Can be located on the first and second floors in the main and auxiliary premises of production,

Section 2 Complete transformer substations and distribution devices 2.1. COMPLETE TRANSFORMER SUBSTATIONS Complete transformer block substations (KTPB) (Fig. 2.1) are designed for receiving, converting and distributing electrical power

2.2. COMPLETE DISTRIBUTION DEVICES A complete distribution device (KRU), consisting of prefabricated one-way service chambers "SamaraElectron-Shield" of the KSO-SESCH series (hereinafter referred to as KSO), is intended for the reception and distribution of electrical energy

4.1.24. Switchgears installed in rooms accessible to uninstructed personnel must have live parts covered with solid fences.

If a switchgear is used with open live parts, it must be fenced. In this case, the fence must be mesh, solid or mixed, with a height of at least 1.7 m. The distance from the mesh fence to the non-insulated live parts of the device must be at least 0.7 m, and from solid ones - in accordance with 4.1.14. The width of passages is taken in accordance with the requirements given in 4.1.21.

4.1.25. The termination of wires and cables must be made so that it is located inside the device.

4.1.26. Removable barriers must be strengthened so that their removal is impossible without the use of tools. The doors must be locked with a key.

4.1.27. The installation of complete switchgears and substations (switchgear switchgear, package transformer substations) must comply with the requirements given in Chapter. 4.2 for switchgear and package substation above 1 kV.

Installation of switchgear outdoors

4.1.28. When installing switchgear outdoors, the following requirements must be observed:

1. The device must be located on a planned site at a height of at least 0.2 m from the planning level and must be designed in accordance with environmental conditions. In areas where snow drifts of 1 m or more in height are observed, cabinets should be installed on elevated foundations.

2. Local heating must be provided in the cabinets to ensure normal operation of devices, relays, measuring instruments and metering devices in accordance with GOST requirements.

Chapter 4.2

Switchgears and substations

Voltage above 1 kV

Scope, definitions

4.2.1. This chapter of the Rules applies to stationary switchgear and alternating current substations with voltages above 1 kV. The rules do not apply to special switchgear and substations regulated by special technical conditions, and to mobile electrical installations.

4.2.2. A switchgear is an electrical installation that serves to receive and distribute electricity and contains switching devices, busbars and connecting busbars, auxiliary devices (compressor, battery, etc.), as well as protection devices, automation and measuring instruments.

An open switchgear (OSD) is a switchgear, all or the main equipment of which is located in the open air.

A closed switchgear is called a switchgear, the equipment of which is located in the building.

4.2.3. A complete switchgear is a switchgear, consisting of fully or partially closed cabinets or blocks with built-in devices, protection and automation devices, supplied assembled or fully prepared for assembly.

A complete switchgear intended for indoor installation is abbreviated as KRU. A complete switchgear intended for outdoor installation is abbreviated as KRUN.

4.2.4. A substation is an electrical installation used for the conversion and distribution of electricity and consisting of transformers or other energy converters, switchgear, control devices and auxiliary structures.

Depending on the predominance of one or another function of substations, they are called transformer or converter.

4.2.5. An attached substation (attached RU) is a substation (RU) directly adjacent (adjacent) to the main building.

4.2.6. A built-in substation (built-in switchgear) is a closed substation (closed switchgear), inscribed (inscribed) in the contour of the main building.

4.2.7. An intra-shop substation is a substation located inside a production building (open or in a separate enclosed room).

4.2.8. A complete transformer (converter) substation is a substation consisting of transformers (converters) and units (switchgear or switchgear and other elements) supplied assembled or fully prepared for assembly. Complete transformer (converter) substations (KTP, KPP) or parts of them installed indoors are classified as indoor installations; those installed outdoors are classified as outdoor installations.

4.2.9. A pole (mast) transformer substation is an open transformer substation, all of whose equipment is installed on structures or on overhead line supports at a height that does not require substation fencing.

4.2.10. A distribution point (DP) is a switchgear intended for receiving and distributing electricity at one voltage without conversion and transformation, which is not part of the substation.

4.2.11. A chamber is a room intended for the installation of devices and tires.

A closed cell is a cell that is closed on all sides and has solid (not mesh) doors.

A fenced chamber is a chamber that has openings protected in whole or in part by non-solid (mesh or mixed) fences.

Mixed fencing refers to fencing made from mesh and solid sheets.

An explosion chamber is a closed chamber designed to localize possible emergency consequences in the event of damage to the devices installed in it and having access to the outside or into the blast corridor.

4.2.12. A service corridor is a corridor along the switchgear chambers or cabinets, intended for servicing devices and buses.

An explosive corridor is a corridor into which the doors of the explosive chambers open.

Page 1 of 12

REQUIREMENTS FOR DISTRIBUTION DEVICES AND TASKS OF THEIR MAINTENANCE

Switchgear units (RU) of substations are complexes of structures and equipment designed for receiving and distributing electrical energy.
Switchgears can be open (OSU) or closed (ZRU). Complete switchgears (KRU) for installation indoors and directly outdoors (KRUN) have become widespread. They are manufactured in stationary and roll-out versions, and are supplied assembled or fully prepared for assembly. Sealed switchgears that use SF6 gas as an insulating and arc-extinguishing medium are called switchgear.

TO The following requirements apply to switchgear equipment::

1. According to its nominal data, the switchgear equipment must satisfy operating conditions both in normal mode and during short circuit. Under normal operating conditions, heating of conductors by current should not exceed the values ​​​​established by the standards. This ensures reliable operation of live parts and guarantees an economically justified service life of the insulation, excluding its accelerated thermal aging. In short circuit mode, the switchgear equipment must have the necessary thermal and electrodynamic resistance.
2. The insulation of the equipment must correspond to the rated voltage of the network and withstand possible voltage increases during switching and atmospheric overvoltages. One of the main conditions for reliable operation of insulating structures is keeping the insulation clean - systematic cleaning, washing, coatings with hydrophobic pastes; for closed switchgear - protection against penetration of dust and harmful gases into the premises; in KRUN - sealing cabinets, coating insulation with hydrophobic pastes.
3. The equipment must operate reliably under permissible overloads, which should not lead to damage and a reduction in its service life.
4. The production premises of the reactor plant must be convenient and safe when servicing equipment by personnel. Switchgear switchgears with voltages of 400 kV and higher must be equipped with biological protection means in the form of stationary, portable or inventory screens, and personal protective equipment - shielding suits. Heating of structures located near live parts accessible to personnel should not exceed 50°C.
5. The temperature and air humidity in the indoor switchgear must be maintained such that dew does not occur on the insulators; the temperature in summer should not exceed 40°C. Ventilation openings should have louvers or metal mesh. Windows in the closed switchgear must be locked or protected with nets, and openings and openings in walls or cells must be sealed to prevent animals from entering. birds. The roof must be in good condition. Floor coverings must not allow the formation of cement dust.
6. The switchgear must be equipped with working and emergency electric lighting. Lighting equipment must be installed in such a way as to ensure safe operation.
7. For personnel orientation, all equipment and especially switching device drives must be provided with clear, conspicuous inscriptions indicating the name of the equipment and the dispatcher name of the electrical circuit to which the inscription refers. In the switchgear, an atypical arrangement of the drive handles of bus disconnectors is unacceptable, when, for example, some disconnectors are turned off by moving the drive handle down, others - up. Switches and their drives, disconnectors, separators, short-circuiters and stationary grounding switches must have “On” and “Off” position indicators. Switchgears must be equipped with an interlock that prevents the possibility of erroneous operations with disconnectors, grounding blades, and short circuiters. Locking devices, except mechanical ones, must be permanently sealed.
8. The RU premises must contain safety equipment and fire extinguishing equipment.

The tasks of maintaining the reactor plant are:

1. ensuring compliance of the operating modes of the switchgear and individual electrical circuits with the technical characteristics of the installed equipment;
2. maintaining at each period of time such a scheme of switchgear and substations so that they best meet the requirements of reliable operation of the power system and trouble-free selective operation of relay protection and automation devices;
3. systematic supervision and care of the equipment and premises of the reactor plant, elimination as soon as possible of identified malfunctions and defects, since their development may lead to operational failures and accidents;
4. control over the timely implementation of preventive tests and equipment repairs;
5. compliance with the established order and sequence of switching operations in the switchgear.

Inspection of the reactor plant without shutting down the equipment should be carried out:

1. at facilities with constant personnel duty - at least once every 3 days, in addition, in the dark to detect the presence of discharges, corona - at least once a month;
2. at facilities without permanent duty - at least once a month, and at transformer and distribution points - at least once every 6 months.
3. after switching off the short circuit.

In case of unfavorable weather (heavy fog, sleet, ice) or increased contamination of the outdoor switchgear, additional inspections are required. During inspection, it is strictly prohibited to perform any work on the equipment.
During inspections of the reactor plant, all comments are recorded in a log of defects and malfunctions and brought to the attention of the managers of the energy enterprise, who take appropriate measures to eliminate the identified violations as soon as possible.
RUs with voltages above 1000 V are operated in accordance with the “Rules for the technical operation of power plants and networks.”
Tests of the electrical equipment of the reactor plant should usually be carried out during periods of its repair.
Routine repairs of the electrical equipment of the reactor plant, as well as checking its operation (testing), must be carried out in accordance with the schedule approved by the chief engineer of the power enterprise, with the exception of unforeseen emergency and other urgent work that is carried out outside the schedule with its own procedure for registering these works.

4.2.81. Indoor switchgears and substations can be located either in free-standing buildings or be built-in or attached. The extension of a substation to an existing building using the building wall as a substation wall is permitted provided that special measures are taken to prevent damage to the waterproofing of the joint during settlement of the attached substation. The specified settlement must also be taken into account when attaching equipment to an existing building wall.

For additional requirements for the construction of built-in and attached substations in residential and public buildings, see Chapter. 7.1.

4.2.82. In the premises of 35-220 kV indoor switchgears and in closed transformer chambers, stationary devices should be provided or the possibility of using mobile or inventory lifting devices to mechanize repair work and equipment maintenance.

In rooms with switchgear, a platform should be provided for repair and adjustment of withdrawable elements. The repair site must be equipped with facilities for testing switch drives and control systems.

4.2.83. Closed switchgears of different voltage classes, as a rule, should be placed in separate rooms. This requirement does not apply to transformer substations of 35 kV and below, as well as switchgear.

It is allowed to place a switchgear up to 1 kV in the same room with a switchgear above 1 kV, provided that parts of the switchgear or substation up to 1 kV and above will be operated by one organization.

The rooms of switchgear, transformers, converters, etc. must be separated from service and other auxiliary rooms (for exceptions, see Chapter 4.3, 5.1 and 7.5).

4.2.84. When assembling GIS in an indoor switchgear, service platforms must be provided at different levels if they are not supplied by the manufacturer.

4.2.85. Transformer rooms and indoor switchgear are not allowed to be placed:

1) under production premises with a wet technological process, under showers, bathtubs, etc.;

2) directly above and below the premises, in which, within the area occupied by the switchgear or transformer rooms, more than 50 people can be present at the same time. for a period of more than 1 hour. This requirement does not apply to transformer rooms with dry transformers or with non-flammable filling, as well as switchgear for industrial enterprises.

4.2.86. The clear distances between bare current-carrying parts of different phases, from bare live parts to grounded structures and fences, floor and ground, as well as between bare current-carrying parts of different circuits must be no less than the values ​​given in Table. 4.2.7 (Fig. 4.2.14-4.2.17).

Flexible busbars in closed switchgear should be checked for their convergence under the influence of short-circuit currents in accordance with the requirements of 4.2.56.

4.2.87. The distances from the moving contacts of the disconnectors in the off position to the busbar of its phase connected to the second contact must be at least AND according to table 4.2.7 (see Fig. 4.2.16).

4.2.88. Non-insulated live parts must be protected from accidental touches (placed in chambers, fenced with nets, etc.).

When placing non-insulated live parts outside the chambers and positioning them below the size D according to table 4.2.7 they must be protected from the floor. The height of the passage under the fence must be at least 1.9 m (Fig. 4.2.17).

Live parts located above the fences up to a height of 2.3 m from the floor must be located from the plane of the fence at the distances given in Table. 4.2.7 for size IN(see Fig. 4.2.16).

Devices in which the lower edge of the porcelain (polymer material) of the insulators is located above the floor level at a height of 2.2 m or more are allowed not to be fenced if the above requirements are met.

The use of barriers in fenced cells is not permitted.

Rice. 4.2.14. The smallest clear distances between non-insulated current-carrying parts of different phases in an indoor switchgear and between them and grounded parts (according to Table 4.2.9)

Rice. 4.2.15. The shortest distances between non-insulated live parts in an indoor switchgear and solid fences (according to Table 4.2.9)

Rice. 4.2.16. The shortest distances from uninsulated live parts in the closed switchgear to mesh fences and between unfenced uninsulated live parts of different circuits (according to Table 4.2.9)

Rice. 4.2.17. The shortest distances from the floor to unfenced uninsulated

current-carrying parts and to the lower edge of the porcelain insulator and the height of the passage into the closed switchgear. The shortest distance from the ground to unfenced linear outputs from the closed switchgear

outside the territory of the outdoor switchgear and in the absence of transport passage under the outlets

4.2.89. Unguarded, uninsulated leading parts of various circuits located at a height exceeding the size D according to table 4.2.7 must be located at such a distance from one another that after disconnecting any circuit (for example, a bus section), its safe service is ensured in the presence of voltage in adjacent circuits. In particular, the distance between unprotected live parts located on both sides of the service corridor must correspond to the size G according to table 4.2.7 (see Fig. 4.2.16).

4.2.90. The width of the service corridor must ensure convenient maintenance of the installation and movement of equipment, and it must be at least (counting the clearance between the fences): 1 m - with one-sided arrangement of the equipment; 1.2 m - with double-sided equipment arrangement.

In the service corridor, where the drives of switches or disconnectors are located, the above dimensions must be increased to 1.5 and 2 m, respectively. With a corridor length of up to 7 m, the width of the corridor for two-way service may be reduced to 1.8 m.

Table 4.2.7

The shortest clear distances from live parts to various elements of the switchgear

(substations) 3-330 kV, protected by arresters, and indoor switchgear 110-330 kV, protected by surge suppressors 1 , (in the denominator) (Fig. 4.2.14-4.2.17)

1 Surge suppressors have a protective level of phase-to-ground switching overvoltages of 1.8 U f.

4.2.91. The width of the service corridor for switchgear with withdrawable elements and package transformer substations should ensure ease of control, movement and reversal of equipment and its repair.

When installing switchgear and package transformer substations in separate rooms, the width of the service corridor should be determined based on the following requirements:

for single-row installation - the length of the largest switchgear trolley (with all protruding parts) plus at least 0.6 m;

with double-row installation - the length of the largest switchgear trolley (with all protruding parts) plus at least 0.8 m.

If there is a corridor at the rear of the switchgear and package transformer substations for their inspection, its width must be at least 0.8 m; Individual local narrowings of no more than 0.2 m are allowed.

When installing switchgear and package transformer substations openly in production premises, the width of the free passage must be determined by the location of the production equipment, ensure the possibility of transporting the largest switchgear elements to the switchgear substations, and in any case it must be at least 1 m.

The height of the room must be no less than the height of the switchgear, package transformer substations, counting from busbar entries, jumpers or protruding parts of cabinets, plus 0.8 m to the ceiling or 0.3 m to the beams.

A lower room height is allowed if this ensures the convenience and safety of replacement, repair and adjustment of switchgear equipment, package transformer substations, busbar inputs and jumpers.

4.2.92. The calculated loads on the floors of premises along the path of transportation of electrical equipment must be taken into account the weight of the heaviest equipment (for example, a transformer), and the openings must correspond to their dimensions.

4.2.93. For overhead inputs into closed switchgear switchgears, package transformer substations and closed substations that do not cross passages or places where traffic is possible, etc., the distance from the lowest point of the wire to the ground surface must be at least E(Table 4.2.7 and Fig. 4.2.17).

At shorter distances from the wire to the ground, in the corresponding area under the input, either fencing the area with a fence 1.6 m high or a horizontal fence under the input must be provided. In this case, the distance from the ground to the wire in the plane of the fence must be at least the size E.

For overhead leads crossing passages or places where traffic is possible, etc., the distances from the lowest point of the wire to the ground should be taken in accordance with 2.5.212 and 2.5.213.

For air leads from the closed switchgear to the territory of the outdoor switchgear, the indicated distances should be taken according to the table. 4.2.5 for size G(see Fig. 4.2.6).

The distances between adjacent linear terminals of two circuits must be no less than the values ​​​​given in table. 4.2.3 for size D, if partitions are not provided between the terminals of adjacent circuits.

In case of unorganized drainage, canopies should be provided on the roof of the indoor switchgear building over the air inlets.

4.2.94. Exits from the reactor plant should be carried out based on the following requirements:

1) with a switchgear length of up to 7 m, one exit is allowed;

2) with a switchgear length of more than 7 to 60 m, two exits must be provided at its ends; it is allowed to locate exits from the switchgear at a distance of up to 7 m from its ends;

3) if the length of the switchgear is more than 60 m, in addition to the exits at its ends, additional exits must be provided so that the distance from any point of the service corridor to the exit is no more than 30 m.

Exits can be made outside, to a staircase or to another industrial premises of category G or D, as well as to other compartments of the switchgear, separated from this one by a fire door of fire resistance class II. In multi-storey switchgears, a second and additional exits can also be provided to a balcony with an external fire escape.

Cell gates with a leaf width of more than 1.5 m must have a wicket if they are used for personnel exit.

4.2.95. It is recommended that the floors of the switchgear rooms be installed over the entire area of ​​each floor at the same level. The design of the floors must exclude the possibility of the formation of cement dust. The installation of thresholds in doors between separate rooms and in corridors is not allowed (for exceptions, see 4.2.100 and 4.2.103).

4.2.96. Doors from the switchgear must open towards other rooms or outwards and have self-locking locks that can be opened without a key from the switchgear side

Doors between compartments of one switchgear or between adjacent rooms of two switchgears must have a device that locks the doors in the closed position and does not prevent the doors from opening in both directions.

Doors between rooms (compartments) of switchgears of different voltages must open towards the switchgear with the lowest voltage.

Locks in the doors of switchgear rooms of the same voltage must be opened with the same key; keys to the entrance doors of the switchgear and other premises should not fit the locks of the cells, as well as the locks of doors in the fences of electrical equipment.

The requirement to use self-locking locks does not apply to switchgear of urban and rural distribution electrical networks with a voltage of 10 kV and below.

4.2.97. Enclosing structures and partitions of switchgear and package transformer substations for the power plant's own needs should be made of non-combustible materials.

It is allowed to install switchgear and package transformer substations for your own needs in process rooms of substations and power plants in accordance with the requirements of 4.2.121.

4.2.98. In one switchgear room with a voltage of 0.4 kV and above, it is allowed to install up to two oil transformers with a power of each up to 0.63 MVA, separated from each other and from the rest of the switchgear room by a partition made of non-combustible materials with a fire resistance limit of 45 minutes, a height of at least height of the transformer, including high voltage bushings.

4.2.99. Devices related to starting devices for electric motors, synchronous compensators, etc. (switches, starting reactors, transformers, etc.) may be installed in a common chamber without partitions between them.

4.2.100. Voltage transformers, regardless of the mass of oil in them, may be installed in fenced switchgear chambers. In this case, a threshold or ramp must be provided in the chamber, designed to hold the full volume of oil contained in the voltage transformer.

4.2.101. Switch cells should be separated from the service corridor by solid or mesh barriers, and from each other by solid partitions made of non-combustible materials. These switches must be separated from the drive by the same partitions or shields.

Under each oil switch with an oil mass of 60 kg or more in one pole, an oil receiver is required for the full volume of oil in one pole.

4.2.102. In closed, free-standing, attached and built-in substations, in the chambers of transformers and other oil-filled devices with an oil mass in one tank of up to 600 kg, when the chambers are located on the ground floor with doors facing outside, oil collecting devices are not installed.

When the mass of oil or non-flammable environmentally friendly dielectric in one tank is more than 600 kg, an oil receiver must be installed, designed to hold the full volume of oil, or to retain 20% of the oil with discharge to the oil sump.

4.2.103. When constructing chambers above the basement, on the second floor and above (see also 4.2.118), as well as when constructing an exit from the chambers into the corridor under transformers and other oil-filled devices, oil receivers must be constructed in one of the following ways:

1) when the mass of oil in one tank (pole) is up to 60 kg, a threshold or ramp is made to hold the full volume of oil;

2) with an oil mass of 60 to 600 kg, an oil receiver designed to hold the full volume of oil is installed under the transformer (apparatus), or at the exit from the chamber there is a threshold or ramp to hold the full volume of oil;

3) with an oil weight of more than 600 kg:

an oil receiver containing at least 20% of the total volume of oil of the transformer or apparatus, with oil drainage into the oil sump. Oil drain pipes from oil receivers under transformers must have a diameter of at least 10 cm. On the side of the oil receivers, oil drain pipes must be protected with nets. The bottom of the oil receiver should have a slope of 2% towards the pit;

oil receiver without oil drainage into the oil sump. In this case, the oil receiver must be covered with a grate with a 25 cm thick layer of clean, washed granite (or other non-porous rock) gravel or crushed stone with a fraction of 30 to 70 mm and must be designed for the full volume of oil; The oil level should be 5 cm below the grate. The top level of gravel in the oil receiver under the transformer should be 7.5 cm below the opening of the air supply ventilation duct. The area of ​​the oil receiver must be greater than the area of ​​the base of the transformer or apparatus.

4.2.104. Ventilation of transformer and reactor rooms must ensure the removal of heat generated by them in such quantities that when they are loaded, taking into account the overload capacity and the maximum design ambient temperature, the heating of transformers and reactors does not exceed the maximum permissible value for them.

Ventilation of transformer and reactor rooms must be carried out in such a way that the temperature difference between the air leaving the room and entering it does not exceed: 15 °C for transformers, 30 °C for reactors with currents up to 1000 A, 20 °C for reactors with currents more than 1000 A.

If it is impossible to ensure heat exchange by natural ventilation, it is necessary to provide forced ventilation, and its operation must be monitored using alarm devices.

4.2.105. Supply and exhaust ventilation with intake at the floor level and at the level of the upper part of the room must be carried out in the room where the switchgear and SF6 gas cylinders are located.

4.2.106. RU rooms containing equipment filled with oil, SF6 or compound must be equipped with exhaust ventilation, switched on from the outside and not connected to other ventilation devices.

In areas with low winter temperatures, supply and exhaust ventilation openings should be equipped with insulated valves that can be opened from the outside.

4.2.107. In rooms where on-duty personnel stay for 6 hours or more, the air temperature must be ensured not lower than +18 °C and not higher than +28 °C.

In the repair area of ​​the closed switchgear, a temperature of at least +5 °C must be ensured during repair work.

When heating rooms that contain SF6 equipment, heating devices with a heating surface temperature exceeding 250 °C (for example, heaters such as heating elements) should not be used.

4.2.108. Holes in the enclosing structures of buildings and premises after laying current conductors and other communications should be sealed with a material that provides fire resistance not lower than the fire resistance of the enclosing structure itself, but not less than 45 minutes.

4.2.109. To prevent the entry of animals and birds, other openings in external walls must be protected with nets or gratings with cells measuring 10 x 10 mm.

4.2.110. Overlapping cable ducts and double floors must be made of removable slabs made of fireproof materials flush with the clean floor of the room. The weight of an individual floor slab should be no more than 50 kg.

4.2.111. Laying transit cables and wires in the chambers of devices and transformers, as a rule, is not allowed. In exceptional cases, their installation in pipes is allowed.

Electrical wiring of lighting and control and measurement circuits located inside chambers or located near non-insulated live parts can be allowed only to the extent necessary for connections (for example, to instrument transformers).

4.2.112. Laying related (non-transit) heating pipelines into the switchgear premises is permitted provided that solid welded pipes are used without valves, etc., and welded ventilation ducts are used without valves and other similar devices. Transit laying of heating pipelines is also permitted, provided that each pipeline is enclosed in a continuous waterproof shell.

4.2.113. When choosing a switchgear circuit containing SF6 devices, simpler circuits should be used than in air-insulated switchgear.