When designing overhead power lines in the Chukotka Autonomous Region, one of our customers faced difficulties in organizing grounding. Geological data indicated too high electrical resistivity of the soil - from 30,000 to 80,000 Ohm * m. This problem is not uncommon in permafrost soils, and the ZANDZ Technical Center specialists have a reliable and proven solution for it: installation of electrolytic grounding kits.
Let us consider in more detail how our engineers solved the problem of designing the grounding device for the overhead line support in permafrost soil.
Task: It is necessary to calculate the grounding device for the support of the overhead power line 110 kV.
object: single-circuit 110 kV overhead line on metal supports of type 1Y110-3 +5 according to the series 3.407.2-170, Chukotka Autonomous Region;
electrical resistivity of soils from 30,000 to 80,000 Ohm * m.
In accordance with EIC, p. 2.5.129 chart2.5.19, the resistance of the grounding device of the 110 kV overhead line should be no more than 480 Ohms.
The set of measures on the provision of the necessary requirements to the grounding device (electrolytic grounding) is presented by the following solutions:
- installation of 7 sets of electrolytic grounding ZZ-100-102 and the implementation of the grounding contour along the perimeter of the overhead line support. The distance from the electrodes to communications and foundations should be at least 3. Depth 0.6 m;
Условные обозначения- Type Codes
Полоса стальная оцинкованная сечением – Galvanized steel tape with the cross section of 30*4 mm
Зажим для соединения проводников – Clamp for connecting conductors
Комплект электролитического заземления – Electrolytic grounding kit
Table 1 - The list of material requirements for one overhead line support.
|№||Figure||Product item||Name||Quantity, pcs.|
|1.||ZZ-100-102||ZANDZ Electrolytic grounding kit (horizontal; 3 m)||7|
|2.||ZZ-005-064||ZANDZ Clamp for connecting conductors (up to 40 mm)||10|
|3.||GL-11075-10||GALMAR Copper-bonded tape (30 * 4 mm / S 120 mm²; coil of 10 meters)||1|
|4.||GL-11075-50||GALMAR Copper-bonded tape (30 * 4 mm / S 120 mm²; coil of 50 meters)||1|
|5.||ZZ-007-030||ZANDZ Waterproof tape||3|
Do you have any questions when designing the grounding system for overhead line supports? Send your request to firstname.lastname@example.org.