Burial depth to the top of the concrete encasement of all primary duct banks shall be 36 inches, minimum. If you've ever had a. NEC 300. 5 is an article in the National Electrical Code that addresses requirements for underground electrical installations, including minimum cover requirements—the measurement used to determine the distance from the top of an underground cable or raceway to the finished grade. 5. Hand digging at depths up to 12" may be permissible, but call 811 for their guidance first. Also, don't forget to reserve any needed rental equipment many days before. The actual trench depth will be greater (approximately 30 inches or 36 inches minimum respectively) to accommodate the underground facility, bedding, enclosures, riser sweeps, and joint trench installations with other utilities. Find out how deep the buried utilities are in this Content The depth of underground lines can vary from a few inches below the surface to more than 10 feet. Underground residential and utility power lines must be installed deep enough to protect them from physical damage caused by digging, landscaping, or surface.
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