Direct Burial Low Voltage Cables

Structured Cable Products Inc ("SCP") provides a full line of low voltage direct burial cables for Datacom, Security-Alarm, Speaker-Audio, and Coax CCTV-CATV. All of our direct burial rated cables are manufactured using materials specifically for direct burial applications. We do not recommend the use of indoor rated PVC jacket cables for direct burial applications.

Is that Cable Really for Direct Burial?

It is becoming a more common occurrence to see competitor brands promoting their indoor rated PVC cables as also direct burial cables. Don't be fooled. Smart installers know that only cables that are specifically manufactured for direct burial applications should be used on those installations. In-wall rated cables do not have the necessary internal construction for direct burial and many outdoor applications. The primary purpose of these cables is for indoor use, not direct burial.

Some PVC jacket cables can be used for direct burial applications with conduit, as a secondary use. However, PVC jacket cables have severe shortcomings that you should be aware of before installing them for any direct burial applications.

SCP highly recommends the use of cables manufactured specifically for direct burial applications. SCP typically uses a specific direct burial cable jacket such as LLDPE, and internal construction components specifically for our direct burial applications. LLDPE stands for Linear Low-Density Polyethylene. LLDPE is superior to PVC in durability, water permeability, and other environmental factors.

Advantages of LLDPE over PVC

  • LLDPE has resistance to a wider range of chemicals as compared to PVC.
  • LLDPE is immune from biological attack by microorganisms. Microorganisms could attack PVC and use the plasticizer as a source of food.
  • LLDPE is resistant to burrowing animals, PVC is not.
  • LLDPE has a lower permeability to methane than PVC.
  • LLDPE retains its physical properties due to long-term soil burial. PVC's physical properties diminish in time due to loss of plasticizer.
  • LLDPE is more resistant to ultra-violet light than PVC.
  • LLDPE is more resistant to ultra-violet light than PVC.

Cable Jacket is the First Line of Defense

Much attention is given to the electrical performance of cables, but it is the outer jacket that is the first line of defense during the transport, installation, and lifetime performance of the cable. That is why choosing the correct outer jacket and physical construction is essential to protecting and extending the cable's lifetime performance. In direct burial applications with or without conduit, cables are more subject to nicks, cuts, and abrasions during installation and environmental factors such as water and temperature extremes that can rapidly degrade the performance of the cable and your installation system. SCP direct burial cables are tough and durable to withstand the rigors of outdoor installation.

Moisture Resistance

In addition to using the correct cable jacket, the cable conductors need to be protected against moisture or water intrusion. All SCP direct burial cables include a water-blocking technology of either gel filled ("flooded") or water blocking tape. These technologies prevent unwanted moisture from reaching the cable conductors where corrosion could begin. A direct burial cable that is gel filled is "flooded" with a compound that prevents air and moisture from coming into contact with the insulated cable conductors... even if the outer jacket has been nicked. A gel filled cable provides maximum moisture protection. Gel filled direct burial construction is recommended in wet or moist installations. Water Blocking Tape is a special moisture repelling material that is wrapped around the cable conductors. It provides excellent moisture protection, but not at the same level as the gel filled. SCP Direct Burial cables are recommended by leading A/V brands.

All SCP direct burial cables have the correct jacket and internal construction for direct burial applications. You can be assured that when properly installed; these cables will support your installation for many years. SCP direct burial cables are recommended by leading A/V brands to support their systems. Our Landscape Speaker Cable series for example has been well promoted to pair with the Sonance® landscape speaker systems.