Future Water Problem

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wireman3736

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Vermont/Mass.
Looking for some opinions on a job I'm going to be doing in the next few weeks. Underground 200 amp service running in 2-1/2" PVC from a pad mount xformer to a new house. house is about 50' from the pad mount, the problem I see is the grade drops about 30-40 yards in that 50' and I'm concerned about moister running down the pipe into the meter socket, has anyone ever dealt with such an incline and what precautions did you take if any. Maybe I'm over reacting but thought I would get others opinions, Thanks.
 
I think it is smart to think of this now. It is a major pain to fix after the fact.

IMO you should make a drain near the 90 at the meter.

Assume that water will get in the raceway and plan a way for it to get out.
 
Check this out, a bit more than moisture.

WaterSpout.jpg


Electric Meter or KC Fountain?
 
Thanks for the response, I think the 1st thing I should do is talk it over with the ahj and get his input also. I didn't know about the legality of making holes in the conduit.
 
I have seen two approaches to this. 1) an open bottomed Quazite box at some point in the run from the padmount to the meter can, arranged as a "C body" for a straight through pull. This will drain any water that comes down the pipe from the xfmr into the stones under the Quazite box. 2) A T-body in the service conduit, turned down and used like a C-body, in place of the coupling at the transition from horizontal to the sweep up into the meter can. This wil drain any water out of the open port of the t-body.

I have seen water percolating up a service conduit into a meter can at the bottom of a hill (just like your description). It's the oddest sight. The one I saw was corrected with a drill, and that's all I have to say about that.
 
You could probably locate and order a listed for the purpose fitting.

Another way is to simply turn the raceway up into a hand hole with crushed stone base than start a new race on to the meter.
 
iwire said:
You could probably locate and order a listed for the purpose fitting..
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That's what I think, too. I've been flipping through catalogs and Google-ing like a madman since this post went up, and darned if I can find one. Surely, somebody makes something. I thought Crouse Hinds would be the one, since they make all the mining fittings, but no dice so far.
 
Wouldn't the conduit need an expansion fitting as it emerges from the ground? From what I remember they aren't water tight and would allow the raceway to drain.
 
infinity said:
Wouldn't the conduit need an expansion fitting as it emerges from the ground? From what I remember they aren't water tight and would allow the raceway to drain.
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No. An expansion fitting is not approved for use when compensating for ground movement. It is only for thermal expansion and contraction of the conduit. Use of an expansion fitting on a meter riser can rip the conductors out of the terminals and bend padmount flags.
 
mdshunk said:
No. An expansion fitting is not approved for use when compensating for ground movement. It is only for thermal expansion and contraction of the conduit. Use of an expansion fitting on a meter riser can rip the conductors out of the terminals and bend padmount flags.
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OK then what do you use? Maybe you call it something else. To me it's an expansion fitting.
 
infinity said:
OK then what do you use? Maybe you call it something else. To me it's an expansion fitting.
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Yep, it's an expansion fitting. I know that many guys use them on meter risers to compensate for ground movement. What I'm saying is that this is not an approved use for that fitting. http://www.nema.org/stds/expansionjoints-pvc.cfm#download

300.5(J) and the explanitory FPN recognizes expansion fittings for this use, but NEMA and UL don't seem to permit it. The "slack box" is the only fitting I know of that will allow the conduit as well as the conductors to work up and down with ground movement. http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220060005983%22.PGNR.&OS=DN/20060005983&RS=DN/20060005983
 
mdshunk said:
No. An expansion fitting is not approved for use when compensating for ground movement.
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Interesting.

Here if you don't use an expansion fitting for ground movement you will fail inspection.
 
iwire said:
Interesting.

Here if you don't use an expansion fitting for ground movement you will fail inspection.
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Same here. Just as mentioned in the FPN of 300.6(J):

300.6(J) Ground Movement. Where direct-buried conductors, raceways, or cables are subject to movement by settlement or frost, direct-buried conductors, raceways, or cables shall be arranged so as to prevent damage to the enclosed conductors or to equipment connected to the raceways.
FPN: This section recognizes ?S? loops in underground direct burial to raceway transitions, expansion fittings in raceway risers to fixed equipment, and, generally, the provision of flexible connections to equipment subject to settlement or frost heaves.
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I don't see where it requires an expansion fitting to be listed for use on the riser emerging from the ground. The requirement is simply to prevent damage as explained in the article and the FPN.
 
there are bleed fittings available for explosion proof installations. Dunno how much water they will pass, tho- mainly just for condensate and such.

I gotta admit I'm struggling to picture a 30-40 yd drop in 50'....
 
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