Steel connected tp PVC conduit

[Zee]

1. Can I run PVC conduit underground for the buried section, and extend both ends
above ground using rigid steel conduit?

2. Is it a good idea?

3. I have heard of the exception in the NEC permitting elbows to be steel in an otherwise non-metallic conduit run to avoid abrasion when pulling wire.

PVC can and does fail in heat and exposure. Hence the Q.

 

[Dennis Alwon]

1. Can I run PVC conduit underground for the buried section, and extend both ends
above ground using rigid steel conduit?

2. Is it a good idea?

3. I have heard of the exception in the NEC permitting elbows to be steel in an otherwise non-metallic conduit run to avoid abrasion when pulling wire.

PVC can and does fail in heat and exposure. Hence the Q.

I do not see a problem since both ends will be bonded at the panels. There would be an issue with the underground portion in the middle being metal but not the way you are proposing.

 

[jaggedben]

I places I have worked the practice was to make the underground/aboveground transition using schedule 80 PVC, and transition to metal raceway (usually EMT) just above grade.

As Dennis mentions you'll need bonding at both ends to make things electrically continuous.

 

[dicklaxt]

What you propose is common practice in Petro Chemical facilities and a RMC elbow below grade was a must for the reason you state as the runs in those plants were very long as a rule.If your runs are short then PVC is acceptable all the way but I wouldn't do that in a permanent installation when exposure to UV will eventually become a problem.

dick

 

[Zee]

Hey guys,
Thanks.
That was much needed input !

Dennis, yes I will bond at both ends, good point. That is why I had thought it was fine. Grounding bushings, as a matter of fact, as the GEC runs in pipe too.

J.Ben, Sched 80 in transition!
yes I like it.
(I was fretting about extending the SCHED 40 PVC a little above ground and then having it crack vs rigid steel a bit underground and then having corrosion (as has happened with pipe on this property)
Matter of fact, I was planning on just using schedule 80 all the way underground too. I would like to make the PVC as strong as possible.

Dick, good to know about how it is done elsewhere. i thought i was alone in worrying about PVC's durability in sunlight. I have seen some atrocious results.