Have you heard about undergrounding? Known as a type of urban intervention, this installation consists of allocating cables for power transmission, telephony and TV in underground galleries. Furthermore, this technique is used in water, gas and sewage networks.
The underground wire can bring many benefits. Among them are: improving urban aesthetics, decreasing visual pollution caused by cables, and increasing safety, since, when broken, wires can cause electric shocks. To learn more about undergrounding, keep reading!
How the installation of undergrounding is done?
Undergrounding is made up of ducts embedded separately in the ground at a depth of at least 50 cm. To make the installation even safer, electric concessionaires use a HDPE (high density polyethylene) duct in the facilities.
In practice, first, a concrete base is made to support the ducts. Then, a cover is made with sand to keep up with the movement of the earth, in order to minimize the impact of the vibration that trucks can cause. To finish the process, the road is covered with pavement or earth again.
The width of the channels will depend on the amount of piping to be buried. However, the most usual option is one meter. In addition to underground electrical wire, junction boxes are installed at varying distances. Depending on the case, larger boxes, known as utility vaults, will also be needed.
These vaults function as underground rooms that host the equipment of the concessionaires, such as shutdown switches and transformers. Generally, they are placed on the sidewalk or in areas more accessible to the consumer.
Change of overhead to underground electrical grid
According to the engineering point of view, the change from overhead to underground power lines can be a little complex. After burying the installations, it is necessary to connect the pipes with the properties. It is at that moment that the junction boxes enter the extension of the road.
Then, it is necessary to make the connection with each of the residences in the neighborhood. A good example of this type of connection is the Oscar Freire Street, located in the Jardins neighborhood in São Paulo, Brazil.
What are the positive and negative points of this installation?
The city of São Paulo has plans to apply undergrounding in up to 25 years, with the project being led by Eletropaulo. This is because these types of underground electric cable have several advantages for the system and the population, such as increased security.
Although the cost to bury power lines is quite high, in the long term this investment is worthwhile, since the system helps to reduce maintenance costs. Another advantage that cities with undergrounding have is the replacement of utility poles with specific lighting options.
For power cables, TV, internet and telephony function in the best way, the ideal is to have high-performance insulators. This way it is possible to guarantee that, even buried, they can transmit a quality signal to consumers.
Another point that needs to be taken into account is the protection against rodents. If not, these animals may enter the pipes and gnaw on the wiring, causing short circuits. However, such problems are much smaller when compared to the existing adversities with overhead cables.
How the maintenance of undergrounding is done?
The maintenance of the underground energy networks is done similarly to the overhead one. In fact, based on the map of the region, the concessionaire can know which utility vault serves the affected region.
Professionals can access the network through these “rooms”, which have enough space for one person to stand. In the areas with undergrounding, the vaults are formed every two blocks. Thus, it is possible to execute maintenance safely.
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The compounds of Polyexcel have features that help make electrical installations for underground and overhead wiring much safer. Do you want to know more about the characteristics of each polymer? Access our website and request the complete technical sheet in the “Contact us” tab.
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