As the name suggests, direct burial underground cables are designed to be run underground. Though it is a type of outdoor electrical wire but does not require any additional covering, conduit, or sheathing to guard it. The cable itself is sturdier and possesses distinct protective materials to keep water, dirt, and dust outside.
Several tests are done on direct burial wire such as crush resistance and water-absorption test to understand if they are resistant to the impact of soil acidity, wet, dry and moist conditions. Electrical wires inside the cable are protected with a solid thermoplastic sheath to restrict moisture.
TYPES OF DIRECT BURIAL CABLES
The most common types of cables with copper conductors are the USE-2, Underground Feeder Cable (UF-B), and Tracer wire whereas cable with aluminum wire is Aluminum URD Direct Burial Wire. For residential purposes, electricians mainly use USE-2 and UF with thermoplastic insulations. Let us read further in detail:
-
USE-2
USE cables bring power from the utility’s transformer to individual houses and are usually black in color. These cables have sturdy XLPE insulation and a conductor made of annealed soft bare copper that resists strident conditions.
-
UF-B Underground Feeder Cable
UF-B cables have trapped bare copper conductor and PVC insulation making it resistant to corrosion, grease, and moisture. These cables are well protected against sunlight and can be used for both indoor and outdoor applications making them a standard choice. It can be used to connect the house with an outdoor power hub such as a garden.
-
Copper Tracer Wire
Professionals use the tracer wire to track downpipes and other underground cables. Generally, these are used in the utility industry or companies managing water, gas, and the installation of fiber optics. As tracer wires are insulated with HMWPE polyethylene, the wire remains waterproof and has superior abrasion resistance.
-
Aluminum URD Direct Burial Wire
Aluminum URD wires are available in Single, Duplex, Triplex, and Quadruplet variations and are used when the need for secondary power distribution circuits arises. 1350-H19 series compressed aluminum conductors and XLPE insulation make them one of the best wires to be used for underground purposes.
-
Fiber Optic Direct Burial Cable
Fiber optic cables are the fastest of the lot but require great care during installation. A slight bend more than the threshold and the inner glass/ polymer strand will snap cause signal loss. By having a protective corrugated metal and strong kevlar/ aramid yarn surrounding the cladding the fiber is protected from mechanical stress and by including a water-resisting gel you keep water out from entering inside the glass core. The fiber optic direct burial cable, while expensive, is a great way to have fibers laid out for interdepartmental communications without having to worry about breakage.
INSTALLATION
-
Digging is the major concern with buried cables. Placement should be considered before beginning with the installation as it should be placed in an area that would not require any digging in the future (please do consider upcoming landscaping projects).
-
For safe installation, the buried cable is governed by many buildings and has an electrical code. Hence, before installing one should always check with the local building department if there are any specific requirements in the particular area.
-
Before starting the project it is a prerequisite to inform the utility services in your city, dial 811 (the national Call Before You Dig hotline) to do so. The message will be circulated to utilities with service lines of a particular area and a representative would visit and mark the lines where you can or cannot dig.
-
One should always create a map indicating where the underground wiring is done and store it in a safe place for future reference.
-
When building your own direct burial coax cable using weatherproof compression connectors is advisable. It maintains the cable’s weatherproofing and keeps the direct burial cable dry from inside. Please note- if the ends are terminated in covered areas such as inside the garage then waterproof connectors are not required.
-
Close down the direct burial Ethernet cable to a jack which may require more pressure though. Later you can use the short patch cable from the jack at each end to the junction box, router, or computer.
-
In the future, if you wish to upgrade the cable you can use outdoor-rated cabling plus conduit (the duct) to swap out cables easily.
WHY SHOULD YOU CHOOSE A DIRECT BURIAL CABLE?
-
Direct burial cables are preferred in places like heavily populated areas where overhead cables are not feasible to implement.
-
Buried cables are considered safe and reliable by drilling contractors as overheard lines are always at a risk of getting exposed to natural conditions such as hurricanes, storms, etc. which may lead to damage.
-
Overhead running wires can be damaged by tree branches or can be touched by a ladder which is not the case of direct burial cable.
-
When direct burial cables are used in the backyard, it gives a clean look. Further, it cuts down the risk of anyone accidentally tripping over the cable.
-
Though, installation expenses make underground power lines way quite expensive but are perfectly safe and are preferred over overhead power lines.
KNOW MORE ABOUT DIRECT BURIAL WIRES
-
Copper and aluminum both are used in underground cables. Though aluminum is inexpensive still copper is used quite often due to its higher electrical conductivity.
-
To reduce the overall expense of the utility companies, modern AA-8000 series aluminum alloys are used as it has properties quite similar to that of copper.
-
XLPE, PVC, and HMWPE are common insulations used for direct burial cables that make cable resistant to abrasion, moisture, and heat.
-
Before finalizing a pace for underground cable work one should look into upcoming landscaping projects too.
-
If in case the project is large and cables are expected to run a long distance one may have to choose the bigger size in order to minimize the power loss caused by voltage drops.
-
In soil, direct burial cables are buried 24 inches deep whereas 18 inches deep when sheltered by concrete though one should always check the local requirement.
-
Terminating gel-type direct burial cables can be deceptive as the gel can be annoying when comes in contact with the skin.
WRAPPING UP
Hopefully, the information helps you make an informed decision when installing direct burial cables. If you need any assistance with choosing the right direct burial underground cable, contact FalconTech. We are the right supplier for network and IT infrastructure cable assemblies.
