ECN Forum
Posted By: sid123456 schedule 40 pvc - 04/05/05 03:55 PM
Is it permissable to use sch 40 for service entrance up a wall if it does not go through the roof? I know underground is sch 80.
Posted By: watthead Re: schedule 40 pvc - 04/05/05 04:35 PM
If it is ok to use SEU or SER I don't see a problem with Sch 40 pvc, and neither have any of my inspectors so far. Although some have asked how my pipe fits so nicely around drip cap etc.. Like they didn't know that if you heat it pvc will bend.
Posted By: Tripp Re: schedule 40 pvc - 09/26/05 04:09 AM
Just came across this thread...5 months later! But to add my two cents to your last sentence, Member "sid", my understanding of the NEC is that:

Schedule 40 is suitable for underground, while it is Schedule 80 that is used more for exposed work, i.e., that is likely to be subject to damage.

Anybody still out there on this thread?



[This message has been edited by Tripp (edited 09-26-2005).]
Posted By: Tesla Re: schedule 40 pvc - 09/27/05 08:41 AM
Schedule 40 dominates the market utterly.

It is used above ground and underground. Wherever you might think to use plastic -- Schedule 40 PVC 'owns' the market.

Schedule 80 is used but rarely. It has a tighter interior dimension and costs more. Hence it is only used when the raceway is exposed to damage.

I work commercial. If any pipe is at risk for 'damage' it is protected by bollards, etc. Schedule 40 rules.

Schedule 80 is practically never used underground. What would be the point?
Posted By: macmikeman Re: schedule 40 pvc - 09/27/05 04:23 PM
Quote"Schedule 80 is practically never used underground. What would be the point?

The point would be that the poco where I work will not allow any service lateral under a street or driveway in sch 40, they demand sch 80 for those area's and won't supply power until it is sch 80.
Posted By: BobH Re: schedule 40 pvc - 09/28/05 12:59 AM
Ah c'mon, he just said sch. 40 "rules" and "utterly". What more do you want? [Linked Image]

[This message has been edited by BobH (edited 09-27-2005).]
Posted By: ShockMe77 Re: schedule 40 pvc - 09/29/05 12:22 AM
"Schedule 40 is suitable for underground, while it is Schedule 80 that is used more for exposed work, i.e., that is likely to be subject to damage."

Like, for instance, when doing a service upgrade on a house where the driveway is within' 3 ft of the RNC?
Posted By: Tripp Re: schedule 40 pvc - 09/29/05 03:56 AM
"...Shedule 80 is used more for exposed work, i.e., that is likely to be subject to damage."

ShockMe77: "Like, for instance,..."

Like anywhere aboveground, duh. [Linked Image] In our neck of the woods, we run Sch. 40 underground, but where it exits the trench, we switch to Sch. 80, anywhere up to 8' above the ground. This is what the AHJ demands.

And regardless of how our AHJ differs from yours, Tesla, refer to NEC 300.5(D)(1) & (4), NEC 300.50(B), and the 2004 UL WhiteBook. [Linked Image]

So unless the definition of a "bollard, etc." is the same definition i would find for Schedule 80 PVC, I'd had to conclude that Tesla is in violation of the NEC when running Sch.40 where "any pipe is at risk for damage."

[This message has been edited by Tripp (edited 09-29-2005).]
Posted By: iwire Re: schedule 40 pvc - 09/29/05 10:04 AM
Quote
So unless the definition of a "bollard, etc." is the same definition i would find for Schedule 80 PVC, I'd had to conclude that Tesla is in violation of the NEC when running Sch.40 where "any pipe is at risk for damage."

I can not agree with you here.

If the the AHJ feels the bollards prevent the PVC from being exposed to physical damage then the PVC can be Sch. 40.

The 'definition' or determination of exposed to physical damage is entirely up to the inspector / AHJ.

I personally do not like exposed PVC at all and most times that I am forced to use it exposed I use 80. [Linked Image]

Coming up out of the ground I use RMC, RMC is also what the local power companies require when placing a riser on their poles. [Linked Image]
Posted By: Tripp Re: schedule 40 pvc - 09/30/05 09:59 PM
iwire: I agree with you that it is up to the AHJ to determine what constitutes "likely to be subject to damage." However, once that determination is made, I think (and I say "I think" here because my codebook is not in front of me: the surgery is complete and we have been successfully separated! [Linked Image] ) that 300.5 (D) (1) & (4) mandates use of Schedule 80. Now I could look this up again in an hour and find i have made a complete fool of myself, so we'll see. But i did look it up before my last post, in which i referenced it, so i'm goin with my gut here.
Posted By: Tripp Re: schedule 40 pvc - 10/01/05 12:46 AM
Hello again, iwire. And to continue from my last post...

While I agree with you that the AHJ gets to determine what is "subject to physical damage" and what is not, 300.5(D(4) clearly states that "Where the enclosure or raceway is subject to physical damage [as determined by the AHJ, if you like ], the conductors SHALL be installed in rigid metal conduit, intermediate metal conduit, SCHEDULE 80 RIGID NONMETALLIC CONDUIT, or equivalent." I can't imagine that Sched. 40 would be considered "equivalent", or else they would not have specified Sched. 80.

What say ye now? I suppose you could still say that hey, if the AHJ says it's okay, then it's okay. True enough, as 90.4 does say "By special permission, the AHJ may waive specific requirements in this Code...." I, however, like to think of the Code as the MINIMUM for safety, and look to the AHJ to makes things maybe more strict, but not more lax. And I take seriously 90.5 "Mandatory Rules, Permissive Rules, and Explanatory Material" when it states that "Mandatory rules of this Code are those that identify actions that are specifically required or prohibited and are characterized by the use of the terms SHALL or SHALL NOT."

And that is my final answer......I think.
And I have stepped down from my soapbox....for now. [Linked Image]
Posted By: iwire Re: schedule 40 pvc - 10/02/05 12:49 PM
I do not follow you.

No bollards the raceway is subject to physical damage, and you must use 80 or metal.

Put bollards in front of raceway and now the raceway is not subject to physical damage. It is not 'still' exposed to physical damage.

90.4 does not enter into this.

Bollards are often used to protect electrical equipment from physical damage.

If I had a raceway that was exposed to physical damage and then I built a wall around it would you still say it was exposed to physical damage just because it used to be exposed to damage?

The bollards do the same thing, assuming they are placed correctly and that would be up to the inspectors discretion.

At least that is how I see it. [Linked Image]

Bob

[This message has been edited by iwire (edited 10-02-2005).]
Posted By: Tripp Re: schedule 40 pvc - 10/02/05 08:09 PM
I agree with you, Bob. It has just taken me a little time to get used to the idea of bollards - common, i guess, in other areas, but not familiar to me. I'm coming around, though, and can see that bollards and such would make the Schedule question irrelevant. Thanks.
Posted By: watersparkfalls Re: schedule 40 pvc - 10/04/05 02:24 AM
anybody want to predict the price of pvc in about a month from now?
its going though the roof and most suppliers around here(wa) say they arent even taking orders right now because of katrina.

for what its worth.

h20
Posted By: George Re: schedule 40 pvc - 10/04/05 05:14 AM
iwire ---

"The 'definition' or determination of exposed to physical damage is entirely up to the inspector / AHJ."

I disagree: The design engineer is the only person who can make that determination. The AHJ can require that engineering if he wishes.
Posted By: iwire Re: schedule 40 pvc - 10/04/05 09:41 AM
George, I never understand you position.

An engineer can design anything they want. [Linked Image]

If the inspector looks at it and says that schedule 40 is exposed to physical damage something will change.

Either the location or the schedule 40 but the inspector can fail it regardless of what an engineer may feel is OK.

Bob
Posted By: gfretwell Re: schedule 40 pvc - 10/04/05 04:04 PM
I agree with Bob. An engineer may be able to cite some obscure data and calculations that say the raceway can sustain the likely physical threat but whether it is "exposed" to that threat is going to be the AHJs call.

The code is complicated enough, we don't need to legislate common sense. These things do seem to be a local decision though. As long as everyone locally is on the same page it is fair. The confusion starts when 2 inspectors, working for the same AHJ, don't agree. Then you are timing your inspections based on the inspector's days off [Linked Image]
Posted By: tdhorne Re: schedule 40 pvc - 11/09/05 07:49 PM
I'm reviving this thread in the hope to learn something. If you were the AHJ:

would schedule 40 PVC between the bottom of the trench and the LB on the wall of a home be "subject to physical damage"?


What about if it is shielded at ground level to protect it from power lawn care equipment.

How about when adjacent to a residential driveway.

I' not being a gadfly here but rather trying to get a sense of were others would come out on this issue. I ask because if everything from one and one half under to eight feet over ground level needs to be schedule 80 I will have to size the runs based on the interior diameter of schedule 80 unless I install a ground box to change conduit types.
--
Tom Horne

[This message has been edited by tdhorne (edited 11-09-2005).]
Posted By: harold endean Re: schedule 40 pvc - 11/10/05 02:27 AM
Bob,

I think that you might know me by now. ( Even though we never met) However if I see a piece of sch 40 PVC and it is all above the grade and not subject to physical damage, than as a AHJ, I would have to pass that job. If I were to allow a piece of SEU because it meets the code, then a piece of PVC would also fit the bill. This is just my 2 cents.
Posted By: George Re: schedule 40 pvc - 11/10/05 04:05 PM
iwire ---

You seem to insist that the AHJ is the only person who has the ability to decide issues such as "likely to be subject to damage." I think that engineers are better positioned to make that decision.

I am just an engineer. I am liable for the work I do. NO ONE tells me to change my plans and material specs unless they accept ALL of my liability.

If you and your office wish to accept full liability for my work, I will allow you to require make decisions about this issue. Until then it is up to me and me alone to decide.

edited to add:

I have no objection to the NEC including a definition of "likely to be subject to damage." That definition might include above ground when outside of the building envelope. If that definition is included in the NEC, while I might oppose the definition, I will follow it.

[This message has been edited by George (edited 11-10-2005).]
Posted By: gfretwell Re: schedule 40 pvc - 11/10/05 05:04 PM
I'm sure we could get a wizzing match going on about who is the most qualified, engineers or building code officials.
It is like arguing that an engineer is the most qualified to quantify the velocity of mass over a given distance but if the cop says you are going 66 in a 55 you still get the ticket.
Posted By: Helectric Re: schedule 40 pvc - 11/10/05 05:27 PM
Just curious..........how do you guys interpret 352.10(f) and 352.12(c) as it relates to this?
Posted By: Helectric Re: schedule 40 pvc - 11/10/05 05:37 PM
You may also want to visit this website and read the section for article 230.
http://www.carlon.com/Documents/IntroGlobalChanges2005NEC.pdf

I know that it's not the same code article being argued here but I think that it adds good perspective.
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