Should a Ground Conductor Be Above or Below a Buried Conduit?

Electrical Conduit

• Electrical conduit is buried below grade, and provides a safe pathway for electrical cable from one point to another. Electrical service is often buried from the roadside utility pole to the point at which it enters a house. Electrical service is also buried when it's installed from a home to a garage or pole barn. The minimum depth for conduit is 4 inches, and for unprotected electrical cable, 18 inches. In some parts of the country, local statute, weather or geographic conditions mandate deeper burial depths.

Electrical Grounding Rod

• An electrical grounding rod is driven into the earth, usually outside a home or building to create the grounded side of the electrical circuit. The ground rod also prevents static electricity buildup. According to electrical codes, grounding electrodes are driven vertically 10 feet into the earth.

Depth Comparison

• Although the leading edge of the grounding electrode is visible 12 to 24 inches above grade, the leading end of the conductor should be 10 feet below grade. On the other hand, electrical conduit is rarely buried that deep. The purpose of the conduit is to protect the electrical cable from physical damage, and therefore, the regulations specify that conduit should be between 18 and 36 inches below grade for most settings.

National Safety Hotline

• Across the country, a national buried electrical safety telephone number is available for homeowners and contractors. By dialing 811, you are connected to a national hotline that can identify the regulations regarding cable and conduit burial in your area. From this number, you can also ask for a technician to come out to a job site and determine where electrical lines are currently buried. Contractors and homeowners should make this call before excavating for a new building project. Severing an underground electrical line while digging can cause severe injury for the worker, and create thousands of dollars in unexpected repair costs.