raceway support

[stew]

I am mounting some 12x12 quad outlet outdoor assemblies on 6x8 posts . I will mount the boxes using strut. The question is do I have to support the pvc that then goes underground?The pipes are 2 2" conduits that will be about 2 ft long before they enter the ground. Are they considered to be supported by the ground ?

 

[bphgravity]

Re: raceway support

I think this would be a judgment call on a per installation basis. If the conduit is firmly held in palce by the backfill and compacting of Earth around the conduit, I think it can suffice. There could be issues with ground movement if the area is in a cold environment.

 

[dcv]

Re: raceway support

Stew
No! No support is needed the back fill earth is enough, support is used in underground duct banks

 

[earlydean]

Re: raceway support

Article 352.30(A) requires RNC conduit (PVC) to be securely fastened within 3 feet of each box or device. Only if your stub-ups were over 3 feet would you have to provide additional support. The backfill is sufficient to securely fasten the conduit in place.
Also of concern would be Article 300.5(D)(4), where protection from physical damage is required, and 300.5(J), where ground movement due to frost or settlement is addressed.