Wednesday, December 5, 2012

How deep should you bury your copper feeder cable, fiber cable?

One of the most common questions we get is "How deep am I going to bury this wire" when it comes to our outside plant copper PE89 cable and outside plant fiber optic cable. Let's find out.

Most OSP cable runs are never as easy as digging a trench, lay cable, done. Your burial depth will be affected by a number of things, for example:

- Crossing under railroad tacks, under roads and highways

- Lakes, ponds and rivers

- Natural obstacles like rocks and trees

- Outside industrial locations with possible soil contamination

- The Frost Depth Line for your location

Now that your thinking about your entire run a bit more, your copper cable should be placed at a minimum depth of 24 inches (610 mm). However, don't only think about what obstacles are in the way of the trencher but find out what future plans the property may have. For example, maybe an area of your run has future excavation on it's mind. Road grading alone takes 24 inches of the top, so you should bury your cable at least 48 inches. You should also double check the requirements of your local code.

If your installing an OSP fiber optic cable, they should be buried at a minimum depth of 3.28 feet (1 Meter) but once again, think about the future!

Site conditions will also be important when selecting your bore depth. Pipelines, sidewalks and roads are just a few examples of what will influence that decision. In these cases the AHJ (Authority Having Jurisdiction) and owner set the minimum bore depth.

You also want to install an armored fiber optic cable for direct burial installations. An "Outdoor Rated Cable" is not enough to be warrantied. You must have an armor for direct burial applications.

Enclosures should provide sufficient space for splicing and proper storage. Enclosure can be in-ground or above ground type. Marker post are recommended to be placed at these locations. Don't forget, to prevent rodent and insect damage it's recommended that all in-ground enclosures with an open bottom have at least 6 inches of tamped gravel that covers the bottom of the enclosure. Pedestals should have gravel under it for at least 6 inches as well.

Oh, don't you feel better. Now install that cable!

"By Mercy Salinas"