Balkans Power Core

Cable Trench Execution in the Vifor Wind Farm

Cable Trench Execution in the Vifor Wind Farm

In the context of the continuous development of renewable energy, the cable trench execution project in the Vifor Wind Farm - one of the implementation phases - represents a significant step toward ensuring a modern and efficient infrastructure. 

Located in Luciu Commune, Pogoanele Town, Buzău County, Romania, this project was carried out during May–June 2025. The purpose of this article is to provide a detailed overview of the work performed, aimed at specialists in the solar and wind energy sectors as well as professionals interested in best practices for electrical energy infrastructure. 

Execution of electric cable trenches

Works for the medium-voltage electric power collection network began with the precise marking of trench routes according to the execution plans.

Excavation was done mechanically, adapted to each circuit width - from 0.60 m to 3.30 m. In total, over 27,000 linear meters of trenches were dug, with depths in compliance with mechanical and electrical protection standards. 

This stage is crucial to ensure a solid and secure foundation for the electrical infrastructure. 

Trench measurements

An important aspect of this project was the accurate determination of trench lengths. The table below shows the trench widths and total lengths:

Trench WidthTotal LengthUnit
0.60 m13,383.0 mm
0.80 m6,316.0 mm
1.10 m1,032.0 mm
2.10 m2,454.0 mm
2.70 m2,156.0 mm
3.30 m1,929.0 mm
0.60 m (under roads)350.0 mm

Laying of cables and protective conduits

After the excavation phase, cables and fiber optics were installed using rigid or corrugated PVC conduits for protection. 
These conduits were essential for the protection of medium-voltage and fiber optic cables. Installation was done on a compacted sand bed of approximately 10 cm and covered with a similar layer. Fixation was made using clamps, and spacing was ensured with separators. In underpass areas, the conduits were installed inside protective formwork. 

Installation of PVC protection and Warning Tape

A crucial detail for the safety of future interventions was the installation of a yellow warning tape with the message "CAUTION ELECTRIC CABLE". This tape was placed approximately 30 cm above the conduits, serving to warn of the presence of cables in the event of future excavation. This safety measure complies with current electrotechnical standards and prevents accidents. 

Backfilling and compaction of trenches 

Once all protection and marking works were completed, trench backfilling was carried out. This stage was performed with granular material or soil resulting from excavation, followed by layered compaction. 

Compaction was performed carefully in successive layers to prevent future settlement. In areas with heavy traffic or road intersections, compacted gravel or concrete was used, according to project specifications. 

Underpasses and directional drilling

For road or canal crossings, directional drilling methods were implemented. This technique enabled the installation of protective conduits under the road surface without affecting existing infrastructure or traffic. In total, 60 m of road crossings and 965 m of canal crossings were executed, demonstrating the flexibility and efficiency of the technical approach used. 

Underpass Type Total Length Unit
Directional drilling (under canals) 965 m m
Directional drilling (under roads) 60 m m

Additionally, concrete milestones (1.40 m tall) were installed to mark the routes every 50 m and at direction change points.  

This article outlines the key phases of the cable trench execution project in the Vifor Wind Farm, emphasizing the importance of each stage in ensuring a safe and efficient infrastructure. By implementing these activities, we contribute not only to the development of renewable energy in Romania, but also to the establishment of high safety and efficiency standards in the energy sector. 
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