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ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Section 2. Sewerage of electricity Overhead power lines with voltage above 1 kV. Crossing and approaching overhead lines with railways
Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE) 2.5.249. The intersection of overhead lines with railways should be carried out, as a rule, by air crossings. On railways with especially heavy traffic * and in some technically justified cases (for example, when crossing embankments, at railway stations or in places where the installation of air crossings is technically difficult), overhead line crossings should be carried out by cable. The intersection of overhead lines with railways in the necks of railway stations and at the junction of the anchor sections of the contact network is prohibited. The angle of intersection of overhead lines with electrified ** or electrified *** railways, as well as the angle of intersection of 750 kV overhead lines with public railways should be close to 90º, but not less than 65º. In the case of non-parallel passage of the air LS of the MPS relative to the railway, the angle of intersection of the air LS with the overhead line should be determined by the calculation of dangerous and interfering influences. * Particularly intensive train traffic includes such traffic, in which the total number of passenger and freight trains according to the schedule on double-track sections is more than 100 pairs per day and on single-track sections - 48 pairs per day. ** Electrified railways include all electrified roads, regardless of the type of current and the voltage value of the contact network. *** Roads subject to electrification include roads that will be electrified within 10 years, counting from the year of construction of the overhead line planned by the project. 2.5.250. When crossing and approaching overhead lines with railways, the distances from the base of the overhead line support to the dimension of the approach of buildings * on non-electrified railways or to the axis of the contact network supports of electrified or electrified roads must be at least the height of the support plus 3 m. These distances are allowed on areas of a cramped route take at least: 3 m - for overhead lines up to 20 kV, 6 m - for overhead lines 35-150 kV, 8 m - for overhead lines 220-330 kV, 10 m - for overhead lines 500 kV and 20 m - for overhead lines 750 kV. Protection of intersections of overhead lines with a contact network by protective devices is carried out in accordance with the requirements given in 2.5.229. * The dimension of the approach of buildings is the limiting transverse perpendicular to the track outline intended for the passage of rolling stock, inside which, in addition to the rolling stock, no parts of buildings, structures and devices can enter. 2.5.251. Distances at the intersection and approach of overhead lines with railways from wires to various elements of the railway must be at least those given in table. 2.5.34. The smallest vertical distances from the wires of the overhead line to various elements of the railways, as well as to the highest wire or carrier cable of electrified railways are determined in the normal mode of the overhead line with the largest sag of the wire (at the highest air temperature, taking into account the additional heating of the wire by electric current or with the calculated linear ice load according to 2.5.55). In the absence of data on the electrical loads of the overhead line, the temperature of the wires is assumed to be plus 70 ºС. In emergency mode, the distances are checked when crossing overhead lines with wires with a cross-sectional area of \u185b\u2bthe aluminum part of less than XNUMX mmXNUMX for average annual temperature conditions without ice and wind, without taking into account the heating of the wires by electric current. With a cross-sectional area of the aluminum part of the wires of 185 mm2 or more, an emergency check is not required. It is allowed to arrange the wires of the crossing overhead line above the supports of the contact network with a vertical distance from the wires of the overhead line to the top of the supports of the contact network of at least: 7 m - for overhead lines with voltage up to 110 kV, 8 m - for overhead lines 150-220 kV, 9 m - for overhead lines 330 -500 kV and 10 m - for 750 kV overhead lines. In exceptional cases, on sections of a cramped route, it is allowed to hang wires of overhead lines and a contact network on common supports. When crossing and approaching overhead lines with railways along which communication and signaling lines pass, it is necessary, in addition to Table. 2.5.34, be also guided by the requirements for intersections and approaches of overhead lines with communication facilities. Table 2.5.34. The smallest distances when crossing and approaching overhead lines with railways
2.5.252. When crossing overhead lines of electrified and subject to electrification of public railways, the overhead line supports limiting the crossing span must be anchored with a normal design. On sections with especially intensive and heavy traffic * of trains, these supports must be metal. It is allowed in the span of this intersection, limited by anchor supports, to install an intermediate support between tracks not intended for the passage of regular passenger trains, as well as intermediate supports along the edges of the railway track of any roads. These supports must be metal or reinforced concrete. The fastening of wires on these supports should be carried out by supporting double-circuit garlands of insulators with blind clamps. The use of supports made of any material with guy wires and wooden single-column supports is not allowed. Wooden intermediate supports should be U-shaped (with X- or Z-shaped connections) or A-shaped. When crossing non-public railways, it is allowed to use lightweight anchor supports and intermediate supports. Fastening of wires on intermediate supports should be carried out by supporting double-circuit garlands of insulators with blind clamps. Supports of all types installed at the intersection of non-public railways can be free-standing or on braces. * Intensive train traffic refers to such traffic in which the total number of passenger and freight trains in total according to the schedule on double-track sections is more than 50 and up to 100 pairs per day, and on single-track sections - more than 24 and up to 48 pairs per day. 2.5.253. On overhead lines with suspension insulators and a non-split wire in phase, the tension garlands of insulators for the wire must be double-circuit with separate fastening of each circuit to the support. Fastening of tension strings of insulators for a split wire in a phase shall be carried out in accordance with 2.5.112. The use of pin insulators in spans of intersections of overhead lines with railways is not allowed. The use of reinforced concrete supports and reinforced concrete attachments at the supports limiting the crossing span as reinforcement ground electrodes is not allowed. 2.5.254. When crossing an overhead line with a railway with forest protection plantations, one should be guided by the requirements of 2.5.207. 2.5.255. The minimum distances from overhead lines to bridges of railways with a span of 20 m or less should be taken as the same as to the corresponding railways according to Table. 2.5.34, and with a span of more than 20 m, they are installed during the design of overhead lines.
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