SER Cable In Underground Conduit

Status
Not open for further replies.
coulter said:
Disclaimer: I'm not a residential guy. As I told bob a couple of years ago, "I'm not sure I've ever seen SE cable". I've read all of this post, and 11 of the 13 pages of the last one.

The quoted statement above baffles me. I've seen this come up several times, and none have had limitations attached. Is this a blanket statement for all cables, all disciplines? Or is this just about residential installations, SE, SER, NM?

Educate me please. I truly don't see why this would be.

carl
Click to expand...

Carl, I think what is being said is that if you have a complete conduit run why pull cable through it when 1) it is usually easier to pulll the individual cables, 2) it's cheaper to pull individ. cables, 3) You probably would have to increase your pipe size.

That being said there really is no reason that the actually pulling on the cable would affect it adversely.
 
My two cents,.. the cable is not listed for the installation , that being said , it does not have to be, the AHJ can give it's or his or her blessing. I also don't think the NEC prohibits the installation of the cable in a conduit underground, this is as grey as it gets , as far as I can see.
 
george

your comparison makes no sense, besides the UL white book, find me in art. 338 under uses permitted that would permit this installation, I stand by my opinion that it is not permitted and will continue to fail this type of installation
 
Rather than comment I figured you guys would find this rather interesting to the topic at hand.

Question 1. I am trying to find a Code article or reference to the use of SE cable in conduit underground. Chapter 9 states that for multiconductor cables, you have to use the actual dimension. This is not a problem, because you just measure the outside diameter. My question is, Is USE cable listed for use in conduit underground? ? R.P.

Answer 1. The use of Type SE or USE in conduit either underground or aboveground is not prohibited by the NEC. However, neither of these cable types is listed for such use so the decision to accept or reject is up to the authority having jurisdiction (AHJ).

The following information may be helpful in considering such a decision. There are two serious concerns with this type of installation. The first is damage to the cable or individual conductors as they are pulled into the raceway. The other is the added resistance to heat dissipation. Both concerns can be addressed to some extent by using a conduit one size larger than required in Chapter 9. This reduces the friction of the pull, making it less likely that the conductors will be damaged during installation, and provides a larger air space to dissipate the heat buildup in the conductors under operating conditions.

In general, such an installation is poor practice and should not be permitted where there are more than two ninety-degree bends in the run of raceway or where the circuit is expected to run at full load (80 percent of rated ampacity) for any length of time. The sole advantage to running SE cables in conduit underground is the ability to replace them, if necessary, without excavating. Of course, the use of THHW conductors in conduit provides this same advantage with none of the drawbacks identified above and is probably more economical as well. ? T.E. Trainor, CMP-7

| Return to top |
 
There was no need for this thread to go on this long. Look up the deffinition of "Location, Wet". It doesn't matter the someone doesen't think that wire in conduit underground are wet, the NEC does.
 
iwire said:
I use SER in PVC underground for temp feeders and will continue to.
Click to expand...


I agree and I would continue to do so as well.

However, for a permanent installation, I would much rather install single conductors. There's just something about pulling SER in conduit that seems "hack" to me. I know that it's code legal but I don't like it. Just a preference.
 
here is another point of view.


Western Section IAEI 101st Annual Meeting

September 19-21, 2005



83. In accordance with the U.L. ?White book?, the installation of Type SE cable is prohibited to be installed underground. If a contractor runs Type SER (4 conductor) cable across the basement of a house, then runs underground through a non-metallic conduit to an unattached garage, is it acceptable to utilize only the three insulated conductors in the SER as long as compliance with 250.32(B)(2) is met? What is the purpose of the listing if the individual conductors are Type XHHW?

Answer: I would say NO. Type SE cable is Listed under the category of Service Entrance Cable (TYLZ), located on page 113 of the 2005 White Book. The Guide Information for TYLZ states ?Type SE ? Indicates cable for aboveground installation. SE cable has not been evaluated for underground installation. This would be a violation of Section 110.3(B). I would say if underground installation is required, then a transition to type USE or USE-2 which is suitable for underground and direct burial installation would be required.
Click to expand...
 
peter d said:
I agree and I would continue to do so as well.

However, for a permanent installation, I would much rather install single conductors. There's just something about pulling SER in conduit that seems "hack" to me. I know that it's code legal but I don't like it. Just a preference.
Click to expand...

I think 110.3(B) could be used as a reason to tag it as a violation . I also think the cable does not have to listed in the first place,.. so there it is:)
 
Cavie said:
There was no need for this thread to go on this long. Look up the deffinition of "Location, Wet". It doesn't matter the someone doesen't think that wire in conduit underground are wet, the NEC does.
Click to expand...

Look up the listing it says aboveground it has not been evaluated for underground nor has been evaluated for use in a raceway.
 
M. D. said:
nor has been evaluated for use in a raceway.
Click to expand...

MD lets not expand the discussion into the raceway question.

The NEC allows without question SE cables in raceways, that is not a fact in dispute.
 
Last edited:
From the western section IAEI meeting quoted above:
SE cable has not been evaluated for underground installation. This would be a violation of Section 110.3(B).
Click to expand...
Does anyone else see a flaw in the logic of this statement?

I tend to agree with the statement accredited to former CMP-7 Chair Trainor, myself:
Answer 1. The use of Type SE or USE in conduit either underground or aboveground is not prohibited by the NEC. However, neither of these cable types is listed for such use so the decision to accept or reject is up to the authority having jurisdiction (AHJ).
Click to expand...

I finally found what I first searched for when this topic came up: Here is my list of the different threads that happened at the same time last time this came up.

What I see as the core of this discussion is the use of the words "underground" and "aboveground". Mike Whitt wrote the UL asking what these terms meant to the UL, and posted their response here.

To the UL, "underground" means "direct burial". Therefore, aboveground is not direct burial. SER in a raceway is not in the "directly buried" condition, so it is perfectly legal, IMO. :)
 
there is no gray area when it comes to SE cable underground, it is a violation of the listing of the cable, and it is a NEC violation, I do not know why anybody would be trying to find loopholes to endorse this type of installation when there other code compliant safe installations, like I have said many times before, I will continue to fail this type of installation
 
mpd said:
there is no gray area when it comes to SE cable underground, it is a violation of the listing of the cable, and it is a NEC violation,
Click to expand...

That is an opinion which you are fully entitled to, but if you follow the links and read the info George you will find that there is gray area.

There is also the fact that there is no electrical safety reason to prohibit SE in conduit underground.
 
mpd said:
there is no gray area when it comes to SE cable underground, it is a violation of the listing of the cable, and it is a NEC violation, I do not know why anybody would be trying to find loopholes to endorse this type of installation when there other code compliant safe installations, like I have said many times before, I will continue to fail this type of installation
Click to expand...


I couldn't find this information, do you have a link for me?
 
Bob, I said it has not been evaluated for such a use, it is not listed for such a use, it is also not required to be listed . This statement better states what I have previously said on this thread.

The use of Type SE or USE in conduit either underground or aboveground is not prohibited by the NEC. However, neither of these cable types is listed for such use so the decision to accept or reject is up to the authority having jurisdiction (AHJ).
Click to expand...


This is what I posted earlier #22
My two cents,.. the cable is not listed for the installation , that being said , it does not have to be, the AHJ can give it's or his or her blessing. I also don't think the NEC prohibits the installation of the cable in a conduit underground, this is as grey as it gets , as far as I can see.
Click to expand...

If I were the AHJ one concern I would have is the effect of "short" 90 degree bends especially if there were 4 of them installed in the raceway.
 
M. D. said:
If I were the AHJ one concern I would have is the effect of "short" 90 degree bends especially if there were 4 of them installed in the raceway.
Click to expand...

It's allowed in raceways, raceways are allowed to have four 90 degree bends.

You could be concerned but you could not fail it strictly because it was in a raceway assuming the installer sized the raceway per the NEC.
 
Status
Not open for further replies.
Top