Building above underground feeder lateral

[OhioAviator]

Hi All,

Does the NEC permit erecting a pole barn-type steel building on top of an underground concrete encased duct bank that is approx. 4-5 ft. below grade? An 8" slab concrete parking lot covers the entire area. The duct bank does not contain any service laterals; only feeder laterals, control conduits, and fiber optic conduits that we control and maintain. The building foundation piers are (supposedly) sited to miss the underground duct bank. The location is Houston, TX. Any advice is appreciated.

Thanks!

 

[dpc]

It would not be an NEC violation. But that won't help when a cable fails under the building.

The NEC is primarily concerned about fire hazards and safety. It does not really address good or bad design practices. I'm sure you realize that accessing a failed cable under the building would be messy.

David Castor

http://www.cvoes.com

 

[OhioAviator]

Thank you, dpc. I couldn't find anywhere in the NEC that prohibited a building on top of an underground duct bank, hence the posting of my question. As for accessing a cable underneath a building, you're preaching to the choir my friend. It certainly isn't my preference to have the building over top of the cables, but in fairness to the operations personnel they really don't have any other options. Hopefully we won't have to find out just how messy that could be!

Again, thanks!

 

[dpc]

Have a look at Article 300.5 in 2008 NEC for more info.

David Castor

http://www.cvoes.com