Installation of new utility cables and power lines often sparks up a heated debate between those who support installation above the ground and those who prefer it to remain underground. While each system has its own advantages and disadvantages, underground installation is usually preferred as it is a safer option. However, underground service equipment is more costly, and as such, all the relevant factors need to be considered and accounted for when embarking on a utility lines construction.
Underground utility cables are safer than above ground ones because all the distribution lines and cables are situated underground which diminishes chances of hazards.
Due to the high costs of special equipment, manholes, cables, trenching and conduits, underground utility systems can be more expensive and costly. In fact, this cost can sometimes be six to ten times more than that of an above ground system.
Utility systems which are above the ground are much more adaptable and flexible than underground ones. For underground systems, duct lines and manholes are placed permanently after installation which means new lines have to be laid out to meet any expansion of load. In contrast, an overhead system allows transformers, wires, and poles to be easily moved around to accommodate any changes in the load.
Since underground utility lines have better insulation, there are fewer chances of faults occurring in comparision to an above ground version. In the event of a defect, it is easy to find and hire a company that provides utility lines construction services.
Underground systems are better in appearance as all the cables and lines are hidden underground. As such, the public is forcing many electric supply companies to move their cables and power lines underground.
Ability to Carry Out Repairs
Although there are fewer chances of faults occurring in an underground system, it is still a possibility. If there is a problem, locating the fault and repairing it would be more difficult whereas, in an overhead system, conductors and transmitters are visible and repair work can be carried out easily.
Current Carrying Capacity
Overhead conductors usually have more current carrying capacity than underground ones. This is true even when both of them are made of the same material and have the same cross-section.
Underground utilities have longer useful lives than over ground ones. An overhead system can last for around 25 years, but an underground one can last more than five decades. This is because underground systems are not exposed to changing weather conditions and therefore, undergo less wear and tear.
Maintenance costs of underground systems are lesser as faults occur rarely. Moreover, weather elements like ice, lightning or wind are unable to interrupt service. In the case of over ground utility systems, even traffic hazards negatively impact them, pushing maintenance costs higher.
Interference with Other Utility Systems
Overhead systems often overlap with telephone services resulting in electromagnetic interference and disturbance. The currents being carried on the power lines mix with the speech currents on the telephone lines, which may hamper communication. However, underground systems do not encounter this problem.
In general, underground systems are usually more effective than those running above ground. However, where it is impractical to construct an underground system or where the law prohibits it, having an over ground system works well.