Tips for networking buildings together with direct burial cable

External wiring to the building is called outside plant cabling. Outside plant cabling can support a wide variety of communications services such as telephone, data transfer, live video, security, building automation control systems and any other low voltage circuitry.

Keep in mind that you must install OSP cable in compliance with National Electric Codes (NEC), National Electric Safety Code (NESC), utility franchise regulations and local building codes.

Before you start laying your cable down OSP cable installation should be based on a 10 year outlook plan. You may consider that the building owner may sell portions of the property so it may be necessary to obtain property easements. Keep an eye out if the cable run is going to cross railroad tracks or other utility company right of way or a natural occurrence such as a pond or stream.


Your OSP cable run will need to be secure. You'll need to provide an alternate route in case of disaster recovery, location of local exchange carrier facilities and the physical terrain of the campus. Extra pathways should be planned for maintenance purposes. It's typically a good idea to check in with your local exchange carrier regarding their facilities within, or adjacent, to the building.

Three pathways are used in outside plant construction. Aerial, underground conduit and direct burial and they can be used in any combination. Today we're going over direct burial installation.

A direct burial cable system is similar to a buried coduit system and has many of the same advantages but, the disadvantage is the capacity cannot be increased. Your cable also doesn't have as much mecanical protection as a buried conduit system.

Things to consider are type of soil and subsurface conditions, the possibility of joint trench use, and the back-filling method. The minimum depth of the trench should be 24 inches unless the local code requirement differs. If a possibility exist of your OSP cable being dug up by accident you may want to bury it deeper for added protection. Continuous planks should be used and placed 1ft below grade level for visual warning. (Trenching in action below).

For direct burial fiber optic cable you need to put down a copper conductor along with your fiber so that your cable can be located by a cable locating instrument in case you need to identify where your underground cable is in the future.

When back filling your OSP cable examine and use clean backfill material. The soil should not have any sharp objects or large rocks that could damage your cable during your backfill. After your backfill is complete your now ready to terminate your cable.

Special thanks to Electrical Construction and Maintenance.

Questions comment below. Thanks!

"By Mercy Salinas"