spacing requirement for ductback

[QES]

any support spacing requirement for underground ductback for RNC?
NEC Art.?

 

[barbeer]

Art. 352 is specific to RNC but I would think when completed a duct bank is designed to support itself altogether. Annex B contains info on duct bank ampacities and such.

 

[QES]

will table 352.30(B) apply for ductbank?

 

[barbeer]

If you are using RNC in your duct bank I think it would, like I said just by the nature of the duct(i.e. poured concrete?) the supporting is well taken care of and you have no worries.

 

[DAWGS]

I would buy the spacers and hold down bars, otherwise it will float on you when the concrete is poured. Cantex, and underground devices sells them.

 

[barbeer]

I would buy the spacers and hold down bars, otherwise it will float on you when the concrete is poured. Cantex, and underground devices sells them.

I actually saw those for the first time last week, they are pretty cool. The things you miss when you don't do the work anymore!:grin: