Why bury utilities like transmission and power lines?
For wildfires like Dixie sparked by dry vegetation near transmission lines, there is a better solution instead of blackouts. Buried utilities, that is, encasing high-voltage transmission lines underground in electrical conduit, protects dry vegetation from errant sparks and helps minimize disruptions to the economy, public health and safety.
The utilities are getting the message. In a surprising recent reversal, the Wall Street Journal reported that, “PG&E Corp. plans to bury 10,000 miles of power lines to reduce wildfire risk throughout Northern California at an estimated cost of up to $20 billion.”
How deep are utility lines buried?
Typically, the depth of the burial depends on many factors including location, weather, local utility requirements and project specifications such as whether the conduit will be encased buried or direct buried.
That said, the National Electric Code (NEC) sets the required burial depth of electric wire in rigid, non-metallic conduit at 18 inches, which keeps it safe from being severed or disturbed. Trenches holding larger duct banks can even reach 10 to 12 feet in depth.
What’s the best electrical conduit for buried utilities?
From galvanized rigid steel to PVC to rigid metal conduit, there are many types of electrical conduit to choose from for below-ground installations of buried utilities. But none possess the benefits and safety for underground utility environments that durable fiberglass conduit offers.
Fiberglass electrical conduit protects critical infrastructure because of it’s high dielectric strength. In fact, UL-listed Champion Fiberglass conduit has a dielectric strength of 55o volts and with our XW wall thickness of 0.25″ it can carry transmission lines up to 125 KV (or more if wall thickness is increased).
Further, it offers low coefficient of friction so fewer pull boxes are required. Plus, with resistance to electrical faults, the electric wire does not melt or weld to the conduit facilitating easy repairs.
Even more, our electrical conduit installs safely and seamlessly with smooth handling in the field and no need for special tools, so it saves time and money in installation.