Overhead Power Connections vs Underground Power Connections

Learn the pros and cons before making the switch

Power connections connect our homes to the power grid, energising appliances and making our lives more comfortable. Those appliances are connected in one of two ways: Traditional overhead and, more recently, underground power connections. Over the years, overhead connections were the only option. However, the introduction of underground connections gave residents and business owners a choice.

Choosing between an overhead or an underground connection depends on many factors. While both can effectively supply power to homes, both connection types have their advantages and disadvantages. The team here at Real Electrical Solutions are here to shed some light on this highly important problem.

Overhead power connections

Advantages of overhead power connections

Despite the emergence of underground power connections, there are still residents who prefer an overhead power connection. Here are some of the advantages of having an overhead cable connection:

Overhead power connections are:

• easier and faster to install.

• easy to repair and maintain.

• safe from floods.

• more cost-efficient.

• longer lasting.

• Able to be installed in any terrain and location.

• Limitless for voltage.

• Great for spotting faults.

Disadvantages of overhead power connections

As with all things, there are disadvantages to an overhead power connection, such as:

• Reduced property attractiveness.

• Weather sensitivity, such as strong winds, rain, extreme heat and dust

• Disruptions caused by wildlife.

• Susceptibility to damage caused by nearby vegetation or vehicle accidents.

• Vulnerability to lightning strikes.

Considerations when installing overhead cable connections

The state of NSW has established safety and technical guidelines for installation of overhead service connections. One of the most important elements of these is the right of the electricity distributor to determine whether a property should be supplied by an overhead cable or underground one. The electricity distributor also approves the type of construction, point of common coupling, point of attachment, and route of service.

Here are some of the factors that must be considered for overhead cable connections:

• Street position of the distributor’s electricity pole.

• Position and height of the point of attachment (POA).

• Use of a transformer on the pole for the service connection.

• Treatment of nearby tall trees and shrubs.

• Clearance requirements.

• The location of additionally required poles.

POA location

In addition to the above noted requirements, the POA must be selected so that the route of services must cross over any swimming pool, vegetation, balconies, entrances, and other essential building features. The installation must also be in accordance with the service provider’s Bush Fire Risk Management Plan

Cable span

The length of the span must also be considered for every installation. For services providing up to 100A, the maximum span is 50m; for services that provide more than 100A, the maximum span is reduced to 30m.

Underground power connections

Less than 7% of Australian homes are connected to the grid by an underground cable connection. While it is becoming more and more popular, implementing underground connections nationwide is still a challenge.

Advantages of underground power connections

Some states, such as Western Australia, have implemented programs to promote underground power lines and connections. NSW, on the other hand, allows for both overhead and underground power connections. Here are the advantages of choosing an underground cable connection:

• Protection from extreme weather conditions.

• Elimination of illegal connections.

• No trimming of vegetation is needed.

• Unaffected by wildlife or vehicle accidents.

• Low maintenance.

• Less wear and tear.

• Improved safety.

• No visual effect on a property.

Disadvantages of underground power connections

Here are some of the major drawbacks of underground power connections:

• Installation is more costly as it requires digging.

• It uses electrical conduits, which add to its cost.

• It is impossible for the property owner to detect any fault and problem along with the connection.

• Repair is more costly.

• It is not suitable for all types of terrain.

• Rerouting and new connections are more complicated to do.

Considerations when installing underground power connections

As with installing overhead power connections, there are also safety and technical factors that must be considered with an underground connection, such as:

• The length and route of the connection.

• Obstructions, such as trees, pools and buildings.

• The location of existing underground services such as like gas, sewer, and water.

• The location of the underground service equipment.

• In NSW, the cost of installation is shouldered by the client.

• The conduit must have a diameter of 40mm.

• The cable must be XLPE insulated, and PVC sheathed.

Distance between lines

A 150mm lateral separation must be observed between the underground service power line, the underground line of the distributor, and the lines of other service providers.

Span and modification

The maximum span of an underground power cabling must not exceed 50m. The cable to be used must also be approved by the electricity provider. When it comes to underground lines, any modification and addition are treated as new installations.

Cost

The installation is also charged to the customer. The customer will not only pay for the cost, but will be in charge of the materials and finding a licensed underground installation contractor.

Notification of Service Work

Once installation is done, the contractor should furnish a Notification of Service Work to the electricity distributor. It must include a sketch of the service route to the customer’s premises.

Contact Real Electrical Solutions for your electrical services needs

Real Electrical Solutions is a team of ASP Level 2 technicians, servicing residential and commercial clients Newcastle, Central Coast, Maitland, and Hunter. We offer overhead and underground connection services, as well as point of attachment upgrades, private pole installations, smart metering solutions, and after-hours emergency work services.

Call us today on 0403 306 842 or email your enquiry to admin@realelectricalsolutions.com and we will contact you back as soon as we can.