| 7.1. Checking the state of the route of overhead lines |
М |
The width of the clearing, the height of trees and shrubs under the wires, the distances of the overhead line elements to the tree trunks and their crowns are measured |
On overhead lines with bare wires, at least 1 time in 3 years, the height of trees and shrubs under the wires is measured as necessary
The distances and width of the glades must comply with the established requirements |
| 7.2. Checking the condition of the foundations of the supports |
М |
The dimensions of chips and cracks in foundations are measured. Reducing the diameter of anchor bolts, gaps between the fifth support and the foundation are not allowed |
Frequency of measurements - 1 time in 6 years
The measured values should not exceed those established in the normative and technical documents and projects of overhead lines |
| 7.3. Checking the condition of the supports |
|
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| 7.3.1. Deflection measurements of metal structures of supports |
М |
Deflections of metal supports and metal elements of reinforced concrete supports are measured. Limit values of tolerances for the deflection arrow (curvature) of the checked elements:
support traverse - 1:300 traverse length
post or strut of a metal support - 1:700 of the length of the post, but not more than 20 mm
belt corners within the panel and lattice elements in any plane - 1:750 element length |
The frequency of measurements is at least 1 time in 6 years and after exposure to overhead lines of mechanical loads exceeding the calculated ones |
| 7.3.2. Support guys control |
М |
The tension in the cable guys of the supports is measured and the integrity of the guys is controlled
The tension in the guys should not differ from the design by more than 20%
Reducing the cross-sectional area of the guy rope should not exceed 10% |
Produced as needed in accordance with TI VL 35 - 800 kV |
| 7.3.3. Control of corrosive wear of metal support elements |
М |
The allowable ratio of the actual cross section of a metal element (part) to that provided for by the project in case of continuous or pitting corrosion must be at least:
0,9 - for load-bearing elements
0,8 - for non-load-bearing elements
0,7 - for scarves
Through corrosion damage, crevice corrosion with the appearance of cracks and destruction of welds, cracks in welds and the near-weld zone, cracks in metal are not allowed. |
Metal supports and traverses, metal elements of reinforced concrete and wooden supports, metal footboards, anchors and cables are subject to control
On overhead lines in zones V - VII degrees of atmospheric pollution, the frequency of measurements is at least 1 time in 6 years, in the rest - in accordance with the PPR |
| 7.3.4. Control of reinforced concrete supports and attachments |
М |
Cracks, deflections, destruction of concrete of reinforced concrete supports and attachments are measured. The values of deflections and defects should not exceed the values specified in Table 12 (Appendix 3.1) |
The frequency of measurements is at least 1 time in 6 years |
| 7.3.5. Inspection of wooden parts of supports |
М |
Deviation of the dimensions of parts from those provided for by the project is allowed within:
by diameter - (-1 +2);
along the length - ± 1 cm per meter of length;
minus tolerance for traverses is not allowed.
Measurements are made on (8 - 10)% of the details of the supports |
The frequency of measurements, as well as the places where the support is controlled, is taken in accordance with the established requirements
Between repairs, the degree (depth, dimensions) of external and internal decay of support parts is measured |
| 7.3.6. Checking the correct installation of supports |
K, M |
See table. 12 (Annex 3.1) |
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| 7.4. Control of wires, lightning protection cables |
K, M |
Distances are measured from wires and lightning protection cables to the earth's surface, to various objects and structures in places of convergence and intersections, between wires of different lines with joint suspension of wires
The distances from the wires of the overhead line to the ground, to the structures and in places of convergence must be at least established by the rules for the installation of electrical installations, it is allowed to reduce the distance from the wires of the overhead line to the details of the supports by no more than 10% |
Measurements are made after exposure to overhead lines of maximum current loads, mechanical loads and ambient temperature above the calculated values, as well as periodically at least 1 time in 6 years at intersections and approaches
During overhauls, measurements are made after replacement, rewiring or wiring of wires (their sections) |
| 7.5. Control of sag booms, distances to overhead line elements |
K, M |
The actual sag should not differ from that provided by the project by more than 5%, provided that it complies with the standard values of distances to the ground and intersected objects
Air distances between the wire and the body of the support, between the wires on the transposition support and on the branches should not be less than 10% of the norms provided for by the project
The difference in sag between wires of different phases and between wires of different overhead lines with joint suspension should not exceed 10% of the design value of the sag |
The frequency of measurements - 1 time in 6 years:
on overhead lines 6 - 20 kV - (1 ± 2)% of spans
on overhead lines 35 - 220 kV - (3 ± 5)% of spans |
| 7.6. Cross-section control of wires and lightning protection cables |
М |
The cross-sectional area of wires and cables is measured, which has changed as a result of the breakage of individual wires |
Permissible reduction in the cross-sectional area of the wires is taken in accordance with the established requirements |
| 7.7. Control of wire and cable connections |
K, M |
See section "Contact connections of wires, lightning protection cables, busbars and connecting bars" |
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| 7.8. Control of insulators and insulating hangers |
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Control of the condition of insulators and insulating hangers is carried out by external inspection |
Checking the condition of glass and polymer suspension insulators installed on overhead lines and any insulators of lightning protection cables is not carried out |
| 7.8.1. Insulation resistance measurement |
К |
The measurement of the resistance of porcelain suspension insulators is carried out with a megaohmmeter for a voltage of 2500 V only at a positive ambient temperature. The resistance of each suspension insulator must be at least 300 MΩ. |
The need to test pin insulators on overhead lines is established by the PPR, taking into account local operating conditions |
| 7.8.2. Measurement of voltage distribution over insulators |
М |
It is produced in supporting and tension garlands with porcelain insulators on energized overhead lines at a positive ambient temperature. The average stress distributions over the hanging porcelain insulators of the garlands are given in Table. 13 (Appendix 3.1). When checking the insulator with a measuring rod, the insulator is rejected if the value of the voltage measured on it is less than 50% indicated in Table. 12(Appendix 3.1). When checking insulators with a rod with a constant spark gap, the insulator is rejected if the breakdown of the gap does not occur at a voltage corresponding to the defective state of the least electrically loaded insulator of the garland |
The frequency of measurements is taken in accordance with the established requirements
If the results of measurements according to clause 7.8.3 are positive, the voltage distribution over the insulators is not checked |
| 7.8.3. Remote check of insulators |
М |
Control is carried out using infrared and / or electron-optical devices |
The rejection of insulators is carried out in accordance with the instructions for use of the instruments. |
| 7.9. Linear control |
М |
Linear fittings must be rejected and subject to replacement if:
the surface of the reinforcement is covered with continuous corrosion;
in the details of the reinforcement there are cracks, shells, flashes, bends;
the shapes and dimensions of the parts do not correspond to the drawings;
axles and other parts of articulated joints have wear of more than 10%.
The distance between the axis of the vibration damper and the point of exit of the wire (cable) from the support or tension clamp, the point of exit from the roller of the multi-roller suspension or from the edge of the protective sleeve should not differ from the design value by more than 25 mm
The distances between the electrodes of spark gaps on lightning protection cables should not differ from the design values by more than ± 10% |
Produced by external inspection |
| 7.10. Checking grounding devices |
K, M |
Produced in accordance with the instructions in section 26. |
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| 7.11. Checking tubular arresters |
K, M |
Produced in accordance with the instructions in section 18. |
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| 7.12. Thermal imaging control |
М |
Produced in accordance with established standards and manufacturer's instructions. |
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