For underground service conductors that are not encased in concrete, how deep must they be buried to require a warning ribbon?

In the context of underground service conductors, the requirement for a warning ribbon is typical for conduit installations to provide information about the presence of underground utilities. For conductors that are not encased in concrete, the National Electrical Code (NEC) stipulates that if they are buried at least 12 inches deep, a warning ribbon indicating the presence of electrical conductors must be installed above them.

Installing the warning ribbon at this depth serves to alert any future excavators of the existing underground utilities, thereby reducing the risk of accidental damage or safety hazards during excavation or construction activities. This safety measure reflects a standard practice in electrical installations, as it prioritizes public safety and the integrity of utility services.

Other depths mentioned relate to different requirements or types of installations; however, the specific standard for requiring a warning ribbon for non-concreted underground conductors is firmly established at the 12-inch depth.