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#34596 - 02/16/04 08:03 PM PVC Conduit
sparky*62 Offline
Member
Registered: 07/27/02
Posts: 20
Loc: Ca.
I have been asked if I can run PVC conduit for eveything in a plant, 480v feeders and low voltage. I can't see anything in the code book that say's I can't. Am I missing something? It doesn't seem very safe unless you bury it.
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#34597 - 02/16/04 08:06 PM Re: PVC Conduit
Ryan_J Offline
Moderator
Registered: 08/19/03
Posts: 1374
Loc: West Jordan, Utah, USA
Unless you have some strange things, such as classified locations or plenums, you can use RNC just about anywhere. I'm not saying that it would be my first choice, but is very versatile in its uses permitted.
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Ryan Jackson,
Salt Lake City
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#34598 - 02/16/04 09:54 PM Re: PVC Conduit
stamcon Offline
Member
Registered: 03/24/01
Posts: 329
Loc: So San Francisco CA
Check with the local building department for any amendments. I know of at least one local city that won't allow any plastic inside(no MC, AC or flex either).
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#34599 - 02/17/04 01:47 AM Re: PVC Conduit
iwire Offline
Moderator
Registered: 01/05/03
Posts: 4391
Loc: North Attleboro, MA USA
Not my first choice either but give the customer what they want.

If you end up doing this really look at the support requirements. Table 352.30(B)

1/2", 3/4" and 1" all require supports every 3 feet

Even 4" requires a support every 7 feet.

These supports "shall be fastened so that movement from thermal expansion or contraction is permitted." 352.30

This means do not use something like a EMT minni or a standard uni strut clip, you must use proper PVC supports that let the PVC slid through them.

Expansion fittings, plan on a lot of these.

IMO it is tough to make PVC look good over a long period of time.

Depending on building construction the support requirements could break the budget.

Say it is a steel truss building that has a 5' to 6' spacing, how will you support every 3'? eek:
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Bob Badger
Construction & Maintenance Electrician
Massachusetts
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#34600 - 02/17/04 06:48 AM Re: PVC Conduit
earlydean Offline
Member
Registered: 12/22/03
Posts: 751
Loc: Griswold, CT, USA
When PVC (poly-vinyl-cloride) burns it emits a very nasty black smoke that contains clorine gas. Is this a concern to the folks in your plant? Nobody plans on having fires, but when or if they occur, will this gas be a problem for evacuation?

Earl
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Earl
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#34601 - 02/17/04 12:42 PM Re: PVC Conduit
Jps1006 Offline
Member
Registered: 01/22/04
Posts: 615
Loc: Northern IL
I thought that was only ABS plumbing pipe that did that. The black PVC.
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#34602 - 02/17/04 12:46 PM Re: PVC Conduit
Ryan_J Offline
Moderator
Registered: 08/19/03
Posts: 1374
Loc: West Jordan, Utah, USA
The emission of the gases it produces is why it is not permitted in a plenum. See 300.22
_________________________
Ryan Jackson,
Salt Lake City
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#34603 - 02/17/04 02:57 PM Re: PVC Conduit
golf junkie Offline
Member
Registered: 04/22/01
Posts: 507
Loc: York, NE
We have rewired parts of a fertilizer plant in all pvc and plastic enclosures.

Nema 12R discos that are less than 5 years old are hardly recognizable on the outside. Inside they are still like new. It's a really nasty environment.

They are slowly replacing all the conveyors and bucket elevators with stainless steel equipment.

Plastic may not offer much impact protection, but it's better than switches that won't operate due to corrosion.

GJ
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#34604 - 02/17/04 03:30 PM Re: PVC Conduit
Roger Offline
Member
Registered: 05/18/02
Posts: 1716
Loc: N.C.
Although all the above reasons for not using PVC for this type of installation are valid, the reason for using it is as GJ says.

I think besides Stainless Steel or Robroy, (which I hate) it is the only way to go in corosive environments.

Roger
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#34605 - 02/17/04 05:03 PM Re: PVC Conduit
golf junkie Offline
Member
Registered: 04/22/01
Posts: 507
Loc: York, NE
What is Robroy?
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