Section 2. Sewerage of electricity

Overhead power lines with voltage above 1 kV. Crossing overhead lines with water areas

Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE)

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2.5.268. The angle of intersection of overhead lines with water spaces (rivers, canals, lakes, reservoirs, etc.) is not standardized.

It is necessary to avoid, if possible, crossing overhead lines into long-term mooring areas for ships (backwaters, ports and other settling points).

The passage of overhead lines over the locks is not allowed.

2.5.269. When crossing navigable sections of rivers, canals, lakes and reservoirs, regardless of the length of the crossing span, as well as non-navigable sections of water spaces with an crossing span of more than 700 m (large crossings), the overhead line supports limiting the crossing span must be end anchors.

For overhead lines with steel-aluminum wires and wires made of heat-treated aluminum alloy with a steel core with a cross-sectional area of ​​the aluminum part for both types of wires of 120 mm2 or more, or steel ropes of the TK type with a cross-sectional area of ​​50 mm2 or more, the use of intermediate supports and lightweight anchor supports is allowed; in this case, the number of intermediate supports between the end supports must comply with the requirements of 2.5.153.

When using intersecting intermediate supports in the span, wires and cables must be attached to them with blind or special clamps (for example, multi-roller hangers).

At the intersections of overhead lines with navigable water spaces, made on intermediate supports with fastening of wires in blind clamps, the vertical distances from overhead line wires with a cross-sectional area of ​​the aluminum part of less than 185 mm2 to ships must be checked for wire breakage in the adjacent span at an average annual air temperature without wind and ice without taking into account the heating of wires by electric current. If the cross-sectional area of ​​the aluminum part is 185 mm2 or more, emergency testing is not required.

2.5.270. The distance from the lowest point of sag of overhead line wires in normal and emergency modes to the level of high (flood) waters on navigable sections of rivers. canals, lakes and reservoirs is determined as the sum of the maximum size of vessels and the shortest distance from the overhead line wires to the size of vessels according to table. 2.5.37.

The sag of the wire is determined at the highest air temperature without taking into account the heating of the wires by electric current.

The level of high (flood) waters is accepted with a probability of exceedance (probability) of 0,01 (recurrence rate 1 time in 100 years) for overhead lines 500-750 kV and 0,02 (recurrence rate 1 time in 50 years) for overhead lines 330 kV and below.

The distances from the lowest point of sag of the overhead line wire to the ice level must be no less than those indicated in the table. 2.5.37. In this case, the sag of the wire is determined at the calculated linear ice load according to 2.5.55 and the air temperature during ice conditions according to 2.5.51.

When crossing overhead lines of 330 kV and above long-term mooring sites for vessels (backwaters, ports and other settling points), the shortest distance to the upper working platforms for vessel maintenance must be ensured according to Table. 2.5.37. The sag of the wire is determined at air temperature according to 2.5.17 without taking into account the heating of the wire by electric current at the maximum permissible values ​​of the intensity of the electric and magnetic components of the electromagnetic field.

Table 2.5.37. The shortest distance when crossing overhead lines with water spaces

* The shortest distance allows passage of floating craft up to 3,5 m high.

2.5.271. The distances from the lowest point of sag of overhead line wires in normal mode to the level of high (flood) waters in non-navigable sections of rivers, cables, lakes and reservoirs must be no less than those given in Table. 2.5.37. The sag of the wire is determined at an air temperature of 15 ºС without taking into account the heating of the wires by electric current.

The distances from the lowest point of sag of overhead line wires to the ice level must be no less than those indicated in the table. 2.5.37. In this case, the sag of the wire is determined at the calculated linear ice load according to 2.5.55 and the air temperature during ice conditions according to 2.5.51.

2.5.272. The intersections of overhead lines with navigable and raftable rivers, lakes, reservoirs and canals must be marked on the banks with signal signs in accordance with the rules of navigation on inland waterways.

“Keep the above-water clearance” signs are installed one on each bank at a distance of 100 m above or below (downstream) the axis of the air crossing. When the river width is up to 100 m, sign boards are installed directly on the overhead line support at a height of at least 5 m.

Warning navigation signs are installed by overhead line owners. The size of the sign, color and lighting mode of the lights must comply with state standards.

See other articles Section Rules for the installation of electrical installations (PUE).

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