SER Cable In Underground Conduit

[iwire]

Bob , now you are saying they meant not direct burial when the stated aboveground installation?? I don't know ,..I think thats a bit of a reach

It's not 'what I am saying now' it is what I have believed through many threads on this same subject. Don't think for a moment this thread is the first time it has come up.

I don't think it's a reach at all as it makes no sense from an electrical safety stand point to prohibit SE in a underground raceway.

 

[mpd]

dennis

the problem I have with SE cable in conduit underground is, both UL & the manufacturers list it for aboveground, it does not take much to damage that outer sheath and what you end up with a bare aluminum equipment ground sitting in water, how long do you think it will last? and when it fails now you have a ungrounded detached garage, that does not sound safe to me, does anybody not think if somebody got hurt because of this type of installation a lawyer would not have a field day with this, for me it cannot get much simpler SE cable aboveground use only. any contractor installing this or inspector passing it, you might want to think about it, someday you may have to defend yourself, that your installation was compliant, get all the info you can and make your own decision, this is my opinion, and everybody is entitled to there own

iwire

sorry I did not see your response that you would not fail it,

 

[stickboy1375]

dennis

it does not take much to damage that outer sheath and what you end up with a bare aluminum equipment ground sitting in water, how long do you think it will last?

Yet they allow this aboveground in a WET location with no problems?? SO your problem is the fact that its below grade? Am I missing something?

 

[LarryFine]

Compare this to THWN in conduit underground. Does it have to be rated for underground use, or only for wet locations.

Why doesn't this apply to any and all conductors and/or cables that are rated for use in wet locations?

 

[mpd]

stickboy

my problem is it not listed for underground, it is listed for aboveground use, if it is listed for aboveground you do not think its a violation to install it underground?

 

[mpd]

larry

why would UL & the manufacture say aboveground, there must be a reason,

 

[Davis9]

Why not use SEU?

Tom

 

[stickboy1375]

stickboy

my problem is it not listed for underground, it is listed for aboveground use, if it is listed for aboveground you do not think its a violation to install it underground?

I don't have my 2005 NEC in front of me, but my 2002 NEC gives a definition of SE as Service-entrance cable having a flame-retardant, moisture resistant covering. also, I visited Southwires website and cannot find anything on restricting the installation underground in a raceway, (I see this method done more than I care to see, and like a few others here I also do not condone this) but I don't see it a violation either.....

 

[stickboy1375]

Why not use SEU?

Tom

Did you mean USE??
When I see this method it usually is because they don't have to install a junction box when they enter/exit the structure... Some people have issues with big ugly pvc boxes on the side of a house...

 

[mpd]

stickboy

the UL white book lists SE cable as aboveground and check out post #26 by M.D,

 

[stickboy1375]

Don't you find it odd that the NEC does not restrict this?

 

[George Stolz]

Pierre, I was hoping you posted something in the thread in addition to the PM, I was hoping to only have to write it once.

"1. ''Underground" and "Direct Burial" are not necessarily the same.

(snip)

I am wondering how you get Synonymous from this statement?

Because, I'm taking it in context with the second statement:

2. The "U" really stands for direct burial.

This makes sense. Underground in terms of cable construction means, able to withstand reasonable abuse from soil. If the cable is not in direct contact with soil, then there's no need for an underground rating. That, I believe everyone agrees with. Edit to add: I think part of the problem is, he was addressing a different form of "underground" between his 1st and 2nd paragraphs.

Unfortunately, Mike apparently neglected to ask for clarification on what "aboveground" means to the UL (or to the CMP, for that matter). Understandably so - I personally would feel pretty stupid for asking what "aboveground" meant without providing the pages and pages of discussion on this site alone surrounding it, to explain why such a seemingly simple question was wasting the fellow's time.

I think the NEC (the egg) or the UL (the chicken) slipped up when they used the phrase "aboveground". I think they were probably just trying to be helpful and distinguish between two types of cable. I think the result of SE cable being seen as "aboveground only" is an unintended side effect of that helpfulness.

Is a basement aboveground? Is a crawlspace? A tornado shelter? A wine cellar? Do any of the folks who say the SER in an underground raceway is illegal have a similar issue with SER wiring in these areas? If not, why not?

Consider that UF and NM have seperate articles, but very similar construction and use. What if they combined the articles, wouldn't this be as confusing as what we're dealing with here? I think there is a good analogy here between USE and SE. These are like siamese twins in need of a seperation.

 

[benmin]

Don't you find it odd that the NEC does not restrict this?

Don't you think it odd that 338.100 permits only bare copper grounding conductor for USE assemblies? Maybe they recognize that bare aluminum corrodes too fast. One split in the SER casing with a little water over time in the underground conduit and it's unlikely the bare aluminum would last.

 

[Pierre C Belarge]

Stick
Have you seen the UL White Book.
SE cable is suitable for above ground
USE is suitable for both, above ground and underground


SERVICE ENTRANCE CABLE (TYLZ)
Type SE — Indicates cable for aboveground installation. Both the individual
insulated conductors and the outer jacket or finish of Type SE are
suitable for use where exposed to sun.
Types USE and USE-2 — Indicates cable for underground installation
including direct burial in the earth. Cable in sizes 4/0 AWG and smaller
and having all conductors insulated is suitable for all of the underground
uses for which Type UF cable is permitted by the NEC. Types USE and
USE-2 are not suitable for use in premises or aboveground except to terminate
at the service equipment or metering equipment. Both the insulation
and the outer covering, when used, on single and multiconductor
Types USE and USE-2, are suitable for use where exposed to sun.


The underlined portion would tend to direct us to the fact that direct buried and underground are treated differently and it may include raceways installed below grade as underground installations. Therefore installing SER in a raceway underground is an underground installation and is not suitable as per the information provided in the UL White Book.

 

[gndrod]

Don't you find it odd that the NEC does not restrict this?

It depends on what is being restricted. There exists a major difference between a wet location above ground and a direct burial failed conduit wet location underground. The experience in reality is that the SE with a shredded jacket that is water submerged in a conduit underground will erode the aluminum conductor.
In the over-head condition there is no direct ground submersed condition to cause the erosion contact degradation. I can personally attest to this event back in 1976 when backhoeing up 50' of trench to find the open SE conductor problem. The PVC evidently was split either during backfill upon installation or soil compaction under heavy equipment traffic and it took the open sheathing cut about 2 years to fail. I believe had the wiring been done in USE copper or insulated aluminum for direct burial, the failure would not have occurred. I did not detail this in a previous thread last year but feel it is necessary for making it a little more clear for you all. Hope this helps.

 

[George Stolz]

I'm going to repost this all by itself, for clarity:

Is a basement aboveground? Is a crawlspace? A tornado shelter? A wine cellar? Do any of the folks who say the SER in an underground raceway is illegal have a similar issue with SER wiring in these areas? If not, why not?

Besides, this is one more post to 100.

 

[stickboy1375]

ALUMINUM SER CABLE SER Service Entrance Cable, Type SE, Style SER. 600 Volt TRIPLE E Aluminum Alloy (AA-8176) Conductors Individual Conductors Rated XHHW-2. Overall Sunlight Resistant PVC Jacket Application Type SE, Style SER service entrance cable is primarily used as panel feeder in multiple unit dwellings; however, may be used in all applications where Type SE cable is permitted. SER may be used in wet or dry locations at temperatures not to exceed 90?C.Voltage rating are 600 volts.


Location, WET. Installations under ground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, and in unprotected locations exposed to weather.


You can't list it as a WET location, then tell me I can't install it there...

 

[benmin]

I'm going to repost this all by itself, for clarity:

Is a basement aboveground? Is a crawlspace? A tornado shelter? A wine cellar? Do any of the folks who say the SER in an underground raceway is illegal have a similar issue with SER wiring in these areas? If not, why not?

Besides, this is one more post to 100.

Sounds like areas below grade. Is not the conduit in question direct burial

 

[Dennis Alwon]

Let me see if I can help some of you to understand what I believe is the issue. The issue is the possibility of the bare aluminum grounding conductor in an SER cable in a conduit underground potential getting exposed when pulled through the conduit.

Even though it is not bare because it is in the jacket of SE cable some believe, rightfully so, that the jacket of SE cable is easily torn and the bare aluminum will be exposed to possible water in the conduit underground.

Now will water corrode aluminum? I guess that depends if some elements of the soil that are corrosive to alum. and get in the conduit. I am not knowledgable enough about this.

Art. 250.120(B) just states that bare conductors cannot come into direct contact with the earth or masonry or where subject to physical damage. It also cannot be terminated within 18" of the earth.

If the wire is in conduit underground is it in contact with the earth-- I say "NO" . Now we have the physical damage question. I cannot answer that either. I would guess it is based on the question above that I didn't know the answer to.

Now art. 230.30 ex(4) & art. 230. 41 ex(4)does seem to tell us we cannot use bare aluminum in conduit underground unless it is part of a cable assembly approved for underground. But these articles are about service laterals & service entrance where the bare wire is a grounded conductor and not a grounding conductor.

Perhaps there is something to the fact that it is a grounded conductor instead of grounding conductor. I would say that if the NEC won't allow a bare aluminum underground in conduit then we may have an issue here.

Does anyone know of an aluminum cable assembly that is approved for conduit underground???? Perhaps they are talking of the SE cable-- Again I don't know.

 

[George Stolz]

Is a basement aboveground? Is a crawlspace? A tornado shelter? A wine cellar? Do any of the folks who say the SER in an underground raceway is illegal have a similar issue with SER wiring in these areas? If not, why not?

Sounds like areas below grade. Is not the conduit in question direct burial

The conduit is directly buried. It serves as the protection for conductors from the soil.

The issue at hand is, is SER (which is for aboveground use) a violation when installed in "other than aboveground" locations? If so, then aren't the locations listed above also "other than aboveground" and in violation of the listing and/or NEC, just the same as a raceway that is underground?