Previous in Forum: Core Grounding Box   Next in Forum: Series Capacitor 3p Motor Starting
Close
Close
Close
6 comments
Rate Comments: Nested
Member

Join Date: Sep 2009
Location: Cocoa, Florida
Posts: 7

PVC Conduit and Steel Enclosures

02/06/2014 2:47 PM

I am trying to find anything in the NEC that covers using PVC conduit, and steel boxes/enclosures for receptacless together. Is it ok to use pvc with steel, or does it have to be pvc to pvc, steel to steel etc.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Guru
Canada - Member - If there is a way to screw someting up, there is someone to do so! Safety - Hazmat - New Member

Join Date: Mar 2007
Location: Iqaluit, NU. Canada
Posts: 1854
Good Answers: 140
#1

Re: PVC Conduit and Steel Enclosures

02/06/2014 4:11 PM

Yes... as long as you use a female threaded adapter at the end of the PVC raceway then use a metal nipple that screws into the female adapter and goes into your box. Of course, the metal box would have to be approved for the location in which you wish to use it.

This is true under the Canadian code (see CEC rule 12-1112) and I am more than willing to bet under the NEC as well.

__________________
Joe Contractor to Electrical Inspector, "What do you mean you are going to make me follow the code?".
Register to Reply Score 1 for Good Answer
Commentator

Join Date: May 2011
Location: Brisbane, Australia
Posts: 62
Good Answers: 3
#2

Re: PVC Conduit and Steel Enclosures

02/06/2014 10:59 PM

Not sure what the rule is there but here you'd also have to ensure each of those metal boxes was properly earthed as well.

Register to Reply
Power-User

Join Date: May 2013
Posts: 351
Good Answers: 22
#3

Re: PVC Conduit and Steel Enclosures

02/07/2014 12:26 AM

The metal boxes will have to be grounded, but the NEC does not prohibit the use of metal boxes with PVC conduit, and threaded PVC connectors will work. Most contractors do not do it since the small PVC boxes take less labor and result in lower cost. Breaker panels are always metal as far as I have seen and frequently have PVC conduit entering them.

Register to Reply
Guru

Join Date: Jan 2006
Location: Tamworth, UK.
Posts: 1782
Good Answers: 45
#4

Re: PVC Conduit and Steel Enclosures

02/07/2014 8:35 AM

I was a technical rep for an agency selling Egatube in the Bristol UK area 50 years ago back in the mid 1960's for a couple of years. It was pioneering work in those days fighting steel-minded apathy and commercial prejudice against the use of plastic conduit.

The limited range of plastic accessories meant you were forced to use metal accessories. Which gave rise to the argument that metal boxes had to be connected using metal conduit because mixing metal and plastic was not permitted. A load of rubbish! -but a popular ploy that seems to persist today - judging by the question.

If that argument failed, you were warned that any saving in labour would be off-set by the cost of extra earth wires - so why bother! All I can say is that those who were not fooled developed techniques in the use of plastic conduit that gave them a distinct competitive advantage.

I am totally out of touch with today's practice but if nothing has changed then mixing metal and plastic is perfectly acceptable - providing rules on earthing/grounding are observed - I guess.

__________________
When arguing, remember mud-slinging = lost ground.
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2394
Good Answers: 203
#5

Re: PVC Conduit and Steel Enclosures

02/07/2014 11:55 AM

It is OK as long as a ground wire of proper size is provided and used just as you would for all PVC conduit systems. PVC branches originate at metal boxes, such as a circuit breaker box, they can also terminate that way. Just remember though to run the ground with a grounding wire. Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Member

Join Date: Sep 2009
Location: Cocoa, Florida
Posts: 7
#6

Re: PVC Conduit and Steel Enclosures

02/07/2014 12:11 PM

Thanks for all the inputs.

Register to Reply
Register to Reply 6 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

4wsilver (1); 89fx (1); gckent (1); horace40 (1); North of 60 (1); old salt (1)

Previous in Forum: Core Grounding Box   Next in Forum: Series Capacitor 3p Motor Starting

Advertisement