detached garage

[George Stolz]

I've had this thread open and sitting for a while. Many may have posted by the time I've hit "submit", so if I'm disjointed from the conversation at this point, forgive me. I've been looking at the March 2006 UL Wire & Cable Marking Guide PDF, and still haven't found anything concrete for either side.

"Underground" is not a listing parameter mentioned in the table found on page 10 of the guide. "Direct Burial", "Outdoor", "Sunlight Resistance" are, but "Underground Use" is not.

I believe the intent is not to forbid a wet-rated cable for underground use, but this precarious premise Mike and MPD are hanging their hat on holds water.

From the guide:

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.

One important note in my opinion, is that everythings talking about what the cables are "for", as in, initially designed to do. Nothing is prohibitive in any of the text I've reviewed. SE may have been designed for aboveground use, but there's not a word of prohibition to enforce that design, that I can see.

 

[JohnE]

Sorry to jump back in so late, but I was away for the weekend.

I'm having as much trouble understanding the opposiong view as mpd is having understanding mine.

It's been posted already, but to recap, I believe the underground rating that mpd, mike and others feel is required is simply for direct buried cables. Not for cables installed in raceways. For cables installed underground in raceways we refer to article 300.5(B).

Article 338 does not override 300 as 338 does not address se cables installed underground in raceway.

I think that Bob, myself, and others have clearly substantiated the position. I don't feel the "opposition" has.

John

 

[jwelectric]

Good work George

Along with what you posted here is page 17

APPENDIX A
WIRE, CABLE AND CORD
DESIGNATIONS
In general, the letter designations assigned to wire, flexible cord and cable in the NEC?, for identification purposes, are established according to a coding system that provides information on intended use, insulation type and insulation temperature rating. This coding system, to which there are exceptions, does not cover all NEC? designations. The coding system is as follows:
U ? Underground use
Page 17

I have said for many years, yes I have been told that I am stupid, that TW conductors installed in conduit underground is a violation of the NEC unless the conductors have the letter ?U? stamped on them.

Although underground is a wet location in is also underground. A dip tank is a wet location but it is also a hazardous location.

The one thing that I get a lot of argument about is that the ?U? means ?direct burial? but I cannot find anything to back this. In Table 310.13 The only words used is ?underground? in 338.2 the only words used is ?underground? and in 338.10(B)(4)(b) the only word used is ?underground? in 340.2 is the first time we see the words ?direct burial?
In 340.10(1) it clearly states, ?For use underground, including direct burial in the earth.?
Here there is a distinction between ?underground and ?direct burial.? 338.10(B)(4)(b) tells us that USE can be installed in accordance of 340 thus giving us permission to install it as ?direct burial.?

In Article 310 at Table 310.13 we will find only three conductors that are listed for underground installations, ?UF?, ?USE? and ?PFA? 85 degree.
In my opinion any other conductor installed underground is in violation of the NEC whether in conduit or not.

 

[JohnE]

In Article 310 at Table 310.13 we will find only three conductors that are listed for underground installations, “UF”, “USE” and “PFA” 85 degree.
In my opinion any other conductor installed underground is in violation of the NEC whether in conduit or not.

Then how do you explain 300.5(B)?

 

[jwelectric]

This is how I would explain it:

300.5(B) Listing Cables and insulated conductors installed in enclosures or raceways in underground installations shall be listed for use in wet locations.

310.7 Direct Burial Conductors
Conductors used for direct burial applications shall be of a type identified for such use.

338.2 Type USE. Service-entrance cable, identified for underground use, having a moisture-resistant covering, but not required to have a flame-retardant covering.

338.10(B)(4)(b) Type USE cable installed as underground feeder and branch circuit cable shall comply with Part II of Article 340. Where Type USE cable emerges from the ground at terminations, it shall be protected in accordance with 300.5(D).

340.10 (1) For use underground, including direct burial in the earth. For underground requirements, see 300.5.

I would use the above sections along with Table 310.13.
Maybe they should have added the word underground to 300.5(B) but I am sure that this one section will not negate the other sections.

Now would you explain why some cables are listed for use underground and others such as TW are not. :?:

 

[JohnE]

Mike,

In all seriousness, your above post seems to support my position. I've read and agreed with many of your posts, and have a lot of respect for you.

I believe that the cables listed for use underground mean that they can be installed underground as is. Direct burial in other words.

Type TW conductor is not a cable, but a conductor as referenced by table 310.13. And as stated in 310.13 "these conductors shall be permitted for use in any of the wiring methods recognized in Chapter 3 and as specified elsewhere in this code."

As you've shown, 300.5(B) requires the conductors or cables to be listed for use in wet locations. 300.5(B) does not require the cables to be listed for underground installations.


John

 

[macmikeman]

Using the logic presented by JW, if I had a basement in my house and I were to wire it with nm-b, I would be in violation. Since basements are below grade level they are therefore "underground" and hence uf cable is the new way to do it right.

 

[jwelectric]

John

I have installed TW and THW in conduit underground many times in the past but this does not make the installation code compliant.

My whole debate revolves around how a conductor is listed in Table 310.13.

Looking at section 310.13 I see:

These conductors shall be permitted for use in any of the wiring methods recognized in Chapter 3 and as specified in their respective tables or as permitted elsewhere in this Code.

When looking at the Application Provisions in Table 310.13 I can only find three types of conductor or cable that states, ?underground? and no where do I see the words ?direct burial.?
I find the permission for ?direct bural? in 340. 338.10 (B) allows me to install USE in direct burial through the reference to 340.

I compare this debate to the debate of NM cable being installed in a raceway on the outside. The raceway is outside therefore the NM cable is outside and in a wet location. 334.12 does not tell me that I cannot install NM cable outside it only says that it can?t be installed where subject to excessive moisture or dampness.

Article 310.7 addresses a conductor that is to be installed as a ?direct burial? conductor. I cannot find the words ?direct burial? anywhere in Table 310.13. All I can find is ?underground.?
One of the things that catches my eye is the reference to Lead Covered conductors where these are allowed under the Application Provisions as an underground installation but UF and USE under the Application Provisions refer us to their Article. It is in these articles that we are given permission to use the conductor as a direct burial conductor. I can also install these conductors in a raceway but the Lead Covered will require a raceway and cannot be direct buried.

Then I go the the UL listing on cables and conductors and find that a conductor or cable that is being used for a underground installation is to have the letter ?U? on it. I also find in UL standards that a conductor or cable that is listed for ?Direct Burial? will be marked as follows:

When evaluated for direct burial use, the product is marked ?FOR DIRECT BURIAL,? ?DIRECT BURIAL,? ?DIR BUR? or ?DIR BURIAL.?

In both the NEC and UL there is a notable difference between ?underground? and ?direct burial.?

All of this addresses the debate whether SE-R can be installed in a raceway underground or not.
The answer to that question is found in 338.10(B)(4)(b) and UL, the answer is clearly NO.

 

[jwelectric]

Using the logic presented by JW, if I had a basement in my house and I were to wire it with nm-b, I would be in violation. Since basements are below grade level they are therefore "underground" and hence uf cable is the new way to do it right.

Should you decide to install UF cable it will have to comply with the provisions of 334.

Some of us already know that the basement of a house is not always underground but it is always inside the house.

 

[iwire]

I thought this would have been settled by now. :lol:

 

[iwire]

Some of us already know that the basement of a house is not always underground but it is always inside the house.

And some of already know that cables and conductors installed in raceways underground only need to be listed as 'wet' per 300.5(B). :lol:

 

[iwire]

I have said for many years, yes I have been told that I am stupid, that TW conductors installed in conduit underground is a violation of the NEC unless the conductors have the letter ?U? stamped on them.

Mike am I following you?

Your view is that there are absolutely no single conductors (other than USE) approved for use in underground raceways as none of them are listed 'underground'?

THWN

RHW

XHHW

TW

All of the above if installed in raceways underground are NEC violations because they do not have a 'U' in the designation?

I think you seriously mistaken. :shock

 

[ty]

Bob,
with all due respect, we are, for purpose of discussion, trying to run SER underground to a detached residential garage.

We must be running SER because we must need the 4th wire, or we want to.

This 4th wire will be used as equipment grounding conductor.

This 4th wire will be bare aluminum, in a covering, or jacket, but Not insulated.

I would think that 250.120(B) might come into play here, because I would feel that the likelyhood of pulling SER through conduit can and will nick the outer jacket which would subject the bare ground to corrosive conditions.
Otherwise, I have to agree with you.

 

[jwelectric]

Mike am I following you?

Your view is that

NEC violations because they do not have a 'U' in the designation?

I think you seriously mistaken. :shock

No, this is not my views but the views of Underwriters Laboratories in the link that George posted.

It is also the views of Article 310.13 of the NEC.

Now I have addressed the section found in 300.5(B) as to the conductors being required to be listed for a wet location. All the conductors that have a ?U? on them will also be rated for a wet location.

Could one of you address the following:

Table 310.13 Application Provisions
338.2
338.10(B)(4)(b)
340.2
330.10(B)(2) and its listing found in UL PJAZ

 

[iwire]

Hi Todd.


IMO 250.120(B) does not prohibit a bare AL EGC in any raceway.

2002 NEC

250.120(B) Aluminum and Copper-Clad Aluminum Conductors. Equipment grounding conductors of bare or insulated aluminum or copper-clad aluminum shall be permitted. Bare conductors shall not come in direct contact with masonry or the earth or where subject to corrosive conditions. Aluminum or copper-clad aluminum conductors shall not be terminated within 450 mm (18 in.) of the earth.

Bob

 

[ty]

Hey, Bob.

I knew that would be your position. But I thought I'd throw it out there ,anyway.

From experience, I don't see how anyone could pull SER through a conduit run, and not expect it to be cut up. It gets nics pulling across wood framing members.

Regardless of your CODE position, do you really think it a good design choice??

 

[jwelectric]

Bob,
with all due respect, we are, for purpose of discussion, trying to run SER underground to a detached residential garage.
.

Ty
This deal of installing SE-R underground will not fly. It is a violation of its listing and labeling as outlined in this insert from UL

SERVICE ENTRANCE CABLE (TYLZ)
GENERAL
This category covers service entrance cable designated Type SE and Type USE for use in accordance with Article 338 of ANSI/NFPA 70, ?National Electrical Code? (NEC).
Service entrance cable, rated 600 V, is Listed in sizes 14 AWG and larger for copper, and 12 AWG and larger for aluminum or copper-clad aluminum. Type SE cable contains Type RHW, RHW-2, XHHW, XHHW-2, THWN or THWN-2 conductors. Type USE cable contains conductors with insulation equivalent to RHW or XHHW. Type USE-2 contains insulation equivalent to RHW-2 or XHHW-2 and is rated 90?C wet or dry.
The cable is designated as follows:

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.

To install the SE-R cable underground even in a conduit will be a violation of the UL listing as well as 338.10(B)(4)(b)

 

[iwire]

Regardless of your CODE position, do you really think it a good design choice??

For most applications no.

I posted this earler in the thread.

The only time we use SE underground it is AL SER installed in PVC raceways there is no issue about the grounded conductor as it is fully insulated.

We do this for feeders for temporary job trailers or temp panels in the buildings.

The reason we do this is that is cost effective as we can come up out of the ground with the PVC and run the SER further without the costs of boxes and terminations.

No one questions it as it is safe, effective and IMO code compliant. 8)

 

[iwire]

Ty
This deal of installing SE-R underground will not fly. It is a violation of its listing and labeling as outlined in this insert from UL

Mike please remember that is simply your opinion, not a code fact as you present it.

Just as my view on this is simply my opinion.

 

[iwire]

Mike am I following you?

Your view is that

NEC violations because they do not have a 'U' in the designation?

I think you seriously mistaken. :shock

No, this is not my views but the views of Underwriters Laboratories in the link that George posted.

It is also the views of Article 310.13 of the NEC.

Now I have addressed the section found in 300.5(B) as to the conductors being required to be listed for a wet location. All the conductors that have a ?U? on them will also be rated for a wet location.

Could one of you address the following:

Table 310.13 Application Provisions
338.2
338.10(B)(4)(b)
340.2
330.10(B)(2) and its listing found in UL PJAZ

Mike your not serious are you?

If you are I will be losing some of my high regard for your NEC knowledge as this idea of yours that any 'W' conductor in a raceway underground is an NEC violation is just plain NUTS! :shock: