What are Overhead Service Drop Cables?
Aluminum overhead cables or service drop cables are the cables that supply outdoor overhead power lines. They have cost-efficient and lightweight aluminum conductors. Let’s learn more about specifics of overhead power lines and the variety of overhead power cables to choose from.
When to Choose An Overhead Electrical Service Wire?
In the past, overhead power lines were predominant in the world, but today, underground service lines have taken preference due to their improved safety. However, there are still many situations in which overhead service lines remain as relevant as ever. First of all, utility companies still use overhead power lines when the price is the main priority of the electrical project. The cost of installing an underground power line can be up to 500 percent higher than the cost of a similar overhead power line; therefore, overhead service is not replaced in many areas across the United States, especially if natural disasters that may cause damage to overhead power lines are unlikely in the area. Overhead power lines are often used in rural agricultural areas because their low cost is a sufficient priority there.
Overhead power lines have a longer life cycle than underground ones. On average, the lifespan of an overhead power line is 80 years, which is two times longer than the 40-year lifespan of an underground line.
In general, you should think of many factors when deciding whether to have an overhead or an underground power line. These include the cost of assembly, cost of maintenance, reliability, life cycle, and many others. If these factors speak in favor of an overhead power line, go for high-quality aluminum service drop cables.
Which Type of Aluminum Service Drop Cable Do I Need?
Now that we have settled the drawbacks and benefits of overhead power lines, let's dwell on the types of aluminum overhead cables.
The three types of aluminum service drop cables are duplex, triplex, and quadruplex. They differ according to the number of conductors and common applications. Let's briefly focus on the role of each of these.
Duplex cables with two conductors are used in single-phase power lines for 120-volt applications. They are frequently used in lighting systems outdoors, including street lighting. Moreover, they are often used in the construction business for temporary service. Fun fact- American duplex overhead cable sizes are named after dog breeds, including setter, shepherd, and chow.
Triplex cables with three conductors are used to carry power from the utility lines to customers, in particular, to the weather head. Again, American triplex service drop cables have an interesting story to their name. They are named after the species of sea animals, such as snails, clams, and crabs. Cable names include Paludina, Valuta, and Minex.
Quadruplex cables with four conductors are designed to supply three-phase power lines. They connect pole-mounted electrical transformers, mostly located in the rural areas, with the service heads of the end-user. Quadruplex cables that pass the requirements of NEC are named after horse breeds, such as Gelding and Appaloosa.
Construction of Aluminum Service Drop Cables
Despite varying purpose and number of conductors, all overhead electrical service wires have similar construction. The conductors of these cables are made of 1350-H19 aluminum alloy.
They have a cross-linked polyethylene XLPE insulation that offers great protection from the risks of outdoors. In particular, it has excellent resistance to moisture, weather conditions, and the impact of various chemicals. The operational temperature of aluminum overhead cables with XLPE insulation is 90 degrees Celsius. Rarely, polyethylene insulation may be applied instead of the XLPE insulation. In this case, the operational temperature is reduced to 75 degrees, which is something to have in mind when thinking about your electrical project. The voltage rating of all overhead electrical service wires is 600 volts.
All aluminum service drop cables have a neutral conductor or a messenger wire. The goal of the messenger conductor is to create a neutral path for electricity to escape and avoid accidents, which is crucial in the environment of outdoor cabling. Messenger wires can be made of different materials, such as AAC, ACSR, or another type of aluminum alloy.
If you would like to receive a consultation about service drop conductors, call us at 1-516-482-6313 or contact us through a 24/7 live chat on our website.
