wireman3736
Senior Member
- Location
- Vermont/Mass.
got sited for using sch 40 under a residential drive way. wanted to get it covered so i changed it to sch, 80, Anyone know of a code requirement for this, the work was in MA,:-?
I suspect that the inspector in this case is trying to strike a balance: "I'll let you run the pipe a bit shallow IF you use a stronger pipe."
Since Article 110 has general requirements for wiring methods to mechanically protect the wires, there is some room for discretion on the part of the inspector.
i guess the answer to my question is there is no nec requirement to use 80, and i don't see any requirement in the ma. Amendments. I just believe the inspector was misinformed about the requirements, if i just threw direct burial in the ditch and ran no pipe then he probably wouldn't have mentioned it. It wasn't a big deal to change it this time.
300.5(5)(d)(4).
(4) Enclosure or Raceway Damage. Where the enclosure
or raceway is subject to physical damage, the conductors
shall be installed in rigid metal conduit, intermediate metal
conduit, Schedule 80 PVC conduit, or equivalent.
Mike, how are conductors under a resi driveway in schedule 40 PVC subject to physical damage as a general rule of thumb?
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It is the opinion of the POCO and others that the gravel, #2s - "fines", can compact and damage the pipe.
Now do I believe that 80 is better than 40? To me that is saying that the "rhythm method" is safer than "protection". Both can fail.