ECN Forum Forums Code Related Discussion NEC & other Code issues SE vs. USE

Bill,
338-1(b)states that USE is identified for underground use.
338-1(a)says nothing about underground use of SE, so I'm guessing that, by omission of the reference to underground use, it is not acceptable, even in pipe.
I'm struggling myself, with the conductors in the SE. I know they are XHHW, which is approved for wet locations, but I'm thinking maybe the uninsulated neutral (aluminum)would be trouble.
It would be nice if Art.338 had a "Uses permitted" & "Uses not permitted" sections like Articles 336 & 339.
It would greatly simplify the installation if I could re-use the SE.

[This message has been edited by Redsy (edited 09-02-2001).]

I think I'll call the inspector.
Meanwhile, how about our own ECN poll?

Can you install SE Cable underground in PVC conduit.

YES or NO?

Typical SE-U with aluminum conductors is not identified for underground use, in raceway or not. It’s because the bare aluminum conductor is subject to corrosion. If it is copper SE-U, then the cable assembly must be specifically identified for use underground.

Type USE is permitted to be installed underground (338-1b) but only where emerging outdoors at electrical equipment (338-2). Type USE is not permitted to be installed indoors, in raceway or not. Individual conductors of THW, THHW, THWN, XHHW (found in SE-U) and RHW-2 (commonly used for trailer feeders) are OK for wet locations and indoors. Any of these cable insulations must be in a raceway that extends from the basement panel to a point outside the structure. The only two cable types I know of that can be run as the main service/feeder indoors without raceway are SE-U and SE-R, neither of which can be direct buried. Splicing is not advised. Use PVC. Arrange raceways to drain.

The original post did not describe the equipment on the pole and I find it doubtful that the utility would permit unfused service conductors to run 30 feet from a customer pole to a structure and not require a service disconnect at the pole. Indeed, since the original inspector did not take exception to the 12 feet from the point of entry to the panel, I would suspect that there IS a disconnect at the pole and these are not service conductors but feeder conductors.

If so, the feeder neutral conductor should be insulated, the feeder cable should include an equipment grounding conductor that runs from the pole service equipment grounding lug or neutral bar in to the basement panel equipment grounding bar (not neutral bar), the structure’s metal water system AND at least one ground rod should be bonded to the basement panel equipment grounding bar (not neutral bar) and the basement panel neutral bar should be left unbonded. Circuits fed by the panel should be wired with neutrals on the neutral bar and EGCs on the ground bar. In some cases you may be permitted to omit the grounding conductor from the feeder, bond the basement panel neutral and treat it as a service disconnect. That is up to the local AHJ.

If the utility really does permit the metered service conductors to be run unfused from the pole to the structure, then all the normal service requirements would apply, in addition to the cable insulation requirements above. I would expect the utility to want a disconnect though or at least to bury unfused conductors at least 24 inches in raceway or not.

If there are errors found in my assertions, NEC references would be appreciated.

[This message has been edited by Max Summerville (edited 09-02-2001).]

Redsy,

I didn't realize that your SE Cable was Aluminum. We can only use Copper SE around here. That may put a different slant on things.

Bill

Max,
Thanks for the in-depth response. Actually, the inspector did take exception to the 10-12' distance. That is why I was called. Apparently, he had no problem with the installation, otherwise.
BTW,
No disco on pole, no objections from anyone. Go figure!

Bill,
We use aluminum SE all the time. I only used copper once, 15 years ago. It was hard to find.
That is one of the reasons I like seeing peoples location on their profiles.
Interesting local regulations.

Man, I like this forum!!

[This message has been edited by Redsy (edited 09-02-2001).]

I got the "cared about" and "didn't care about" items backwards. I'd say both the installer and the inspector were not doing very well at their respective duties. Seems the inspector was more concerned that someone might drive a nail into exposed service cable in the cellar than he was that the cable might loose a neutral due to corrosion or be dug up by a tiller with no protection at the pole.

That's the way it is in this area(suburban Phila). Some of the AHJs are township employees(retired electricians or maintenance men, even retired policemen, or family members of local officials) with little, if any, formal training. Some are actual employees of inspection agencies. But it's always a crap shoot, depending on the town.

You offer good insight, Max. Stick around!



[This message has been edited by Redsy (edited 09-03-2001).]

338.2 Definitions.
Service-Entrance Cable. A single conductor or multiconductor assembly provided with or without an overall covering, primarily used for services, and of the following types:
Type SE. Service-entrance cable having a flame-retardant, moisture-resistant covering.
Type USE. Service-entrance cable, identified for underground use, having a moisture-resistant covering, but not required to have a flame-retardant covering.

Notice that the difference between the two cable types is that type USE is not required to have a flame retardant outer jacket. That is what limits it to outdoors, if sunlight resistant, and underground. Type SE has all the characteristics of Type USE and it also has a flame-retardant covering. Type SE can be used anywhere that type USE can be used as well as being used as feeder and branch circuits in any application were type NM can be used.
--
Tom H

Tom please take a look at the UL white book information I posted on the other SE thread.

UL does not list SE for other than above ground use.

https://www.electrical-contractor.net/ubb/Forum2/HTML/001764.html

The letter "U " as used in USE and SEU for Service entrance cable mean different things. In USE the "U" stands for Underground. The "U" in SEU stands for- Are you ready? The U stands for "Unarmored" to show that it is different from the Service Cable that used to have an armor on it to prevent damage and theft of electricity. Found it in an old, old electrician's hand book.