Installation Scenarios

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George Stolz

George Stolz

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Windsor, CO NEC: 2017
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Hospital Master Electrician
Scenario #1: A URD run comes into the back of a panelboard in a basement, from the earth outside the basement wall. Is a sleeve required through the concrete wall?

Scenario #2: There is a utility pole. There is a meterbase, which has a 2" offset nipple out the bottom to a disconnect. A PVC LB exits the side of the disconnect enclosure, and PVC runs down into the earth offering physical protection for a URD run.

The LB is connected to the can by gluing a two inch piece of PVC into the LB, and then a coupling is cut in half and glued to the stub. So, the only exposed piece of PVC conduit is that 1/16" where the conduit penetrates the can, and the coupling's pressure against the LB holds it in place. Legal or illegal?

Code references, please. :)

(Before anybody asks, no, I'm not involved in something personally. One question occurred to me reading a different thread, and the other question was posed to me by a third party who shall remain nameless.)
 
opinion:
1. Sleeving required. Thru the block is not "underground" NEC 300.5 (D)
LB termination: Fittings not being used per mfg design. Violation, yes;
acceptable, up to AHJ. NEC 110.3
 
#1) It is my opinion that the URD is not even permitted to enter the building. That is assuming that the URD is really Underground Service Entrance Cable. 338.12(B)
#2) Violation of 352.6 and 110.3(B)
 
1. Yes.

2. Use one of those 'box adapters' that are basically a non-threaded PVC version of a chase nipple. Poke it out of the disco and glue it right into the LB.
 
subjective answers for #2:
300.6 Protection againest Corrosion and Deterioration.

1/16" huh? Why didn't they use insulated lock washer on the PVC?
Why didn't one use a one-sided threaded bushing (the exact name elodes me.) that would have pulled the elbow in or an I missing that.

I couldn't find it but I thought any alteration of equipment voids the ul list
those voiding the application. yeah

110.3(B)Installation and Use

or

Art 100 Identified
 
George Stolz said:
Scenario #1: A URD run comes into the back of a panelboard in a basement, from the earth outside the basement wall. Is a sleeve required through the concrete wall?
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I agree that the URD may not be allowed inside the house , however, how would you seal the block wall from water penetration with the URD running thru the block. A sleeve, IMO, is necessary if it were a URD that was allowed in the house-- someone has said that they make one with dual ratings.
 
benaround said:
George, 352.46 and 300.5(C) IMO would be violations of the described install.
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I agree with 352.46, and I didn't see that one when I answered the question. :cool:

I disagree with citing 300.5(C) (as worded in the 2005), as the conductors do not pass under the building, but through the sidewall of the foundation.

don_resqcapt19 said:
#1) It is my opinion that the URD is not even permitted to enter the building. That is assuming that the URD is really Underground Service Entrance Cable. 338.12(B)
#2) Violation of 352.6 and 110.3(B)
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On #1, what about an installation under the 2005 NEC?

Looking at the 2008 NEC, it becomes apparent that USE cannot be brought into a basement in this fashion, based on 338.12(B)(1) and (2). The enclosure enters into an indoor location. I assume this is due to the characteristics of the smoke produced by USE?

On #2, those were the only two code citations I could find on that issue at the time. :)

Larry Fine said:
1. Yes.

2. Use one of those 'box adapters' that are basically a non-threaded PVC version of a chase nipple. Poke it out of the disco and glue it right into the LB.
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1. 2005 Code reference?

2. Is that what that fitting is designed for? I thought that fitting was a bushing for use in open-bottomed equipment. Is that an acceptable fitting for securing PVC to a box?
 
George,
It is still a violation under the 2005 code. Take a look at the White Book. The 08 code change was only made because many installers do not read the White Book and were installing USE in violation of its listing.
 
George Stolz said:
2. Is that what that fitting is designed for? I thought that fitting was a bushing for use in open-bottomed equipment. Is that an acceptable fitting for securing PVC to a box?
Click to expand...

If this is the fitting under discussion then yes. It is called a pvc box adapter.
u407197.jpg
 
George Stolz said:
LarryFine said:
1. Yes.

2. Use one of those 'box adapters' that are basically a non-threaded PVC version of a chase nipple. Poke it out of the disco and glue it right into the LB.
Click to expand...
1. 2005 Code reference?
Click to expand...
How about 300.4 or 300.5(2)?

2. Is that what that fitting is designed for? I thought that fitting was a bushing for use in open-bottomed equipment. Is that an acceptable fitting for securing PVC to a box?
Click to expand...
Link:
LarryFine said:
What I'm talking about is on the upper-left corner on PDF page 3, catalog page 176: http://www.carlon.com/Master%20Catalog/Conduit_Fittings_Schedule_40_and_80.pdf
Click to expand...
"Adapts nonmetallic conduit to all electrical enclosures by inserting adapter through knockout and cementing into Carlon couplings."
 
LarryFine said:
How about 300.4 or 300.5(D)(2)?
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I don't buy 300.4 (what is the physical damage we're protecting from?), but I think 300.5(D)(2) could work. I don't like the way it's worded, though, it's kinda weird. :)

Thanks for clearing me up on the use of those gismos. Apparently, he originally asked the homeowner to buy one of those (don't pursue the homeowner aspect of this, please) but they bought the wrong item or something. So he thought he'd get away with making his own as described in the OP. The inspector didn't buy it.

I'd never have thought of using something like that, I would have used a connector, locknut and bushing. :)
 
don_resqcapt19 said:
George,
It is still a violation under the 2005 code. Take a look at the White Book. The 08 code change was only made because many installers do not read the White Book and were installing USE in violation of its listing.
Click to expand...
Well, hopefully the 2008 language clears that up, because it's a little known violation around here, I think. :)
 
don_resqcapt19 said:
George,
It is still a violation under the 2005 code. Take a look at the White Book. The 08 code change was only made because many installers do not read the White Book and were installing USE in violation of its listing.
Click to expand...

Don

My supplier carries URD that is service entrance rated. I don't see how that would be a violation 338.12(B) 1
 
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