underground cable important

Underground Cable: How Important It Is?

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Do you know almost all electric power utilities distribute a part of the electric energy they sell through underground cable systems?

In the countryside, their population is particularly dense and the land is costly or environmentally sensitive. Utilizing aerial cables that carry high-voltage electricity supported by large pylons are generally unattractive features.

Thus, the usage of underground cables may be a practical alternative to the aerial cables.

Find out more about underground cable by reading this article.

What Is Underground Cable?

underground cable

Underground cable transmits and distributes electric power underground in which the practice of overhead construction becomes impracticable to make use.

As mentioned earlier, congested areas are preferable to make use of underground cable where local ordinance prohibits overhead lines for the reason of safety or plants and substation that can not do overhead crossings.

Various types of underground cable available due to different voltage and service requirements.

Recently, improvement has been made in design and manufacturing which lead to the development of cables suitable for high voltage electricity use. This has made transmission of electric power for short or moderate distances possible.

Underground cable consists of one central core or a number of cores (two, three or four) of tinned stranded copper conductors.

Sometimes aluminum conductors are also used to insulate from each other by paper or varnished cambric or vulcanized bitumen or impregnated paper.

A metallic sheath of lead or alloy or of aluminum is provided around the insulation to protect it against ingress of moisture.

Types & Classification of Underground Cable

1. Number of conductors in the cable

– Single core cable

Usually used for higher voltage than 66 kV.

– Three core cable

The maximum voltage it can hold is only 66 kV.

2. Voltage rating of the cable

voltage rating cable

– Low tension cables: Hold until a maximum voltage handling capacity of 1000 V (1kV).

 High tension cables: Hold until a maximum voltage handling capacity of 11kV.

 Super tension cables: Hold until a maximum voltage handling capacity of 33 kV.

– Extra high tension cables: Hold until a maximum voltage handling capacity of 66 kV.

 Extra super voltage cables: Used for applications with voltage requirements above 132 kV.

3. Installation and Laying of The Cable

Direct Buried: The conductors are buried underground in a trench without additional accessories. Cooling pipes are added, sometimes, if required. 

Once the cables are installed, there’s no visible sign above the ground.

 Trough: Concrete troughs are dug and cables are installed in them. It’s visible on the surface and easy to maintain.


underground cable

Tunnels are dug up for the purpose of if a river needs to be crossed or if the intended power distribution is to a major city.

Just like trough, maintenance is easier as well as for future expansion. However, it is costly.

 Gas Insulated Lines: A new technology, where it’s suitable for cables operating at higher voltages and currents, and handling power.

It’s mainly used for advanced projects.

More article to read more information:

Renewable energy in Malaysia You Should Know

Advantages of Installing Underground Cable

1. Require Less Space

Aerial power and communications lines take up a lot of space because they require oles to hold them on the surface and take up space alongside buildings and trees.

Since densely populated areas are precious, the underground cable is chosen.

The only thing underground cable requires is a narrower band of land to be installed.

2. Less Visual Impact

Underground cabling is kept underground, hence cables are completely out of sight and unobtrusive to any property.

Aerial cabling, on the other hand, can easily obstruct a property’s view as well as destroy the curb appeal and decrease the overall value of a property.

3. Less Exposure to Damage

Due to being exposed to nature, aerial cables are more vulnerable to damage.

The damages could be getting chewed on by animals, the pole getting hit by cars or a tree branch fell onto the cable.

With the application of underground cabling, the cabling will work regardless of changes in nature.

4. Less Dangerous

The damage to aerial power lines poses a safety risk to anyone near them.

The collapsed aerial cable onto buildings can harm the people inside them. It also imposes powerful electric shocks to anyone near the collapse.

Underground cabling is less susceptible to damage and is not as easily accessible to people. So, it does not pose many risks to people.

Now that you know how beneficial it is to practice underground cabling over overhead lines, it is time to opt for safer, reliable, and cost-effective cable systems.

It is really beneficial, especially in suburbs, dense populations or countryside areas where there is limited space for overhead lines.

Which is why we are at Setia UrusHarta, an engineering service provider here to fulfill services related to the engineering world.

setia urusharta

Relating to interconnection facilities, we provide supply and installation underground cable as well as overhead cable and HDD. Both jointing and termination services are provided here.

Customer satisfaction is what keeps our service going as what our vision believes.

With our core team of dynamic individuals with passion and dedication, we aim to maintain and ensure we deliver only the best services.

Located in Kajang, Selangor; we also offer other engineering service such as:

Building services

Large pipe repair and installation

Renewable energy


As well as services related to integrated facilities management such as:

Facilities engineering maintenance services

Cleansing services

Softscape and hardscape maintenance

To those that are interested in our service, you can visit our website for more details.

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