Service Entrance Conductors

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I have a client who will not accept any cable type for use as a service entrance cable unless it has been tested for UL Standard 854. Their stance is that Article 338 only permits type USE for underground service entrance and type SE for above ground service entrance.
They also point to NEC Article 230.43 (7), only service entrance cables as acceptable wiring methods.
I intended to design a riser on a pole for a 240/120, 1ph service with XHHW-2 copper conductors in rigid conduit but the specification sheet on the cable didn't specifically state that it was UL Standard 854 approved. Everywhere I look I see single conductor cables coming out of weatherheads but I can't find one cable company that has a single conductor that shows to be UL 854 approved.
Now they want me to design the conduit riser with a 3/c w/ground SE cable with an outer jacket. This will be very hard for the contractor to install.
I am new to service drop pole designs and am confused as to what type of cables are being installed on service drop pole risers.. It appears that my client is misinterpreting something in the code but I can't find anything to convince them otherwise.
Please help. Thanks
 
UL Std 854

UL Std 854

The UL White Book is web downloadable, and here Std 854 is referenced:
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.
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. Type SE cable contains Type RHW, RHW-2, XHHW, XHHW-2, THWN or THWN-2 conductors. Maximum size is 4/0 AWG copper or 300 kcmil aluminum or copper-clad aluminum.
Types USE and USE-2 ? Indicates cable for underground installation including direct burial in the earth. Maximum size is 2000 kcmil. Cable in
sizes 4/0 AWG copper, aluminum or copper-clad aluminum 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. Multiconductor Type USE cable contains conductors with insulation equivalent to RHW or
XHHW. Multiconductor Type USE-2 contains insulation equivalent to RHW-2 or XHHW-2 and is rated 90?C wet or dry. Single- and multiconductor
Types USE and USE-2 are not suitable for use in premises. Single- and multiconductor Types USE and USE-2 are not suitable 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.
Submersible Water Pump Cable ? Indicates a multiconductor cable in which 2, 3 or 4 single-conductor Type USE or USE-2 cables are provided in a flat or twisted assembly. The cable is Listed in sizes 14 AWG to 4/0 AWG inclusive, copper, and 12 AWG to 4/0 AWG inclusive, aluminum or copperclad aluminum. The cable is tag marked ??For use within the well casing for wiring deep-well water pumps where the cable is not subject to repetitive handling caused by frequent servicing of the pump units.?? The insulation ay also be surface marked ??Pump Cable.?? The cable may be directly buried in the earth in conjunction with this use.

As you can see the outer jacket XHHW is clasified as type SE. Hope this clarifies your question.
Pedro Alc?ntar
 

GoldDigger

Moderator
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Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I have a client who will not accept any cable type for use as a service entrance cable unless it has been tested for UL Standard 854. Their stance is that Article 338 only permits type USE for underground service entrance and type SE for above ground service entrance.
They also point to NEC Article 230.43 (7), only service entrance cables as acceptable wiring methods.
I intended to design a riser on a pole for a 240/120, 1ph service with XHHW-2 copper conductors in rigid conduit but the specification sheet on the cable didn't specifically state that it was UL Standard 854 approved. Everywhere I look I see single conductor cables coming out of weatherheads but I can't find one cable company that has a single conductor that shows to be UL 854 approved.
Now they want me to design the conduit riser with a 3/c w/ground SE cable with an outer jacket. This will be very hard for the contractor to install.
I am new to service drop pole designs and am confused as to what type of cables are being installed on service drop pole risers.. It appears that my client is misinterpreting something in the code but I can't find anything to convince them otherwise.
Please help. Thanks

I would start by noting that 338 defines Service Entrance Cable, types SE and USE, and states where they can and cannot be used. The section does NOT state that no other wiring methods can be used. Take a look at the next section, 340, which states about UF:

340.12 Uses Not Permitted. Type UF cable shall not be used as follows:
(1) As service-entrance cable

To me, that is indirect evidence that any wiring method that is NOT called out as not suitable for service-entrance use and is used within its specific limitations is permitted.

SE and USE are inexpensive, relatively simple to install, wiring methods for Service Entrance use, but not necessarily the only ones. The fact that SE and USE are not allowed in many non Service applications says to me that they are inferior rather than superior materials. (If you are into specious value judgements.)

To restate it:
The 3xx sections deal with wiring methods and where each can be used, not with uses and what wiring methods can be used for those purposes. Your customer has it backwards.
 
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Smart $

Esteemed Member
Location
Ohio
... It appears that my client is misinterpreting something in the code but I can't find anything to convince them otherwise.
Please help. Thanks
See following...

230.43 Wiring Methods for 600 Volts, Nominal, or Less.
Service-entrance conductors shall be installed in accordance
with the applicable requirements of this Code covering
the type of wiring method used and shall be limited to
the following methods:
(1) Open wiring on insulators
(2) Type IGS cable
(3) Rigid metal conduit
(4) Intermediate metal conduit
(5) Electrical metallic tubing
(6) Electrical nonmetallic tubing (ENT)
(7) Service-entrance cables
(8) Wireways
(9) Busways
(10) Auxiliary gutters
(11) Rigid polyvinyl chloride conduit (PVC)
(12) Cablebus
(13) Type MC cable
(14) Mineral-insulated, metal-sheathed cable
(15) Flexible metal conduit not over 1.8 m (6 ft) long or
liquidtight flexible metal conduit not over 1.8 m (6 ft)
long between raceways, or between raceway and service
equipment, with equipment bonding jumper
routed with the flexible metal conduit or the liquidtight
flexible metal conduit according to the provisions
of 250.102(A), (B), (C), and (E)
(16) Liquidtight flexible nonmetallic conduit
(17) High density polyethylene conduit (HDPE)
(18) Nonmetallic underground conduit with conductors
(NUCC)
(19) Reinforced thermosetting resin conduit (RTRC)
 

ceb58

Senior Member
Location
Raeford, NC
Now they want me to design the conduit riser with a 3/c w/ground SE cable with an outer jacket. This will be very hard for the contractor to install.
I am new to service drop pole designs and am confused as to what type of cables are being installed on service drop pole risers
I intended to design a riser on a pole for a 240/120, 1ph service
If this is a service riser you cannot use 3c W ground SER for a single phase service.
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
I think they are hung up on cable -vs - conductor. If they want a cable, then you don't need a riser unless some physical damage protection is required (i.e. conduit sleeve only). Putting cables in a complete raceway is a pain because the raceway needs to be so large.

Individual conductors in a raceway is done all the time for service entrances. If overhead, you need to be sure the conductors are wet rated (e.g. XHHW, THWN) and sunlight resistant (varies my manufacturer, but it is stamped on the insulation).
 
Thanks to all of you for your comments and support. We had come to the same conclusions but needed to have this feedback to insure us that we were interpreting the code correctly. Suemarkp, my boss said the same exact thing as your first sentence when I told him what I was dealing with.
He called our State Electrical Inspector and he also agrees with everything that you all of said.
Now our job is to try to convince the client's representative that he is wrong in a nice way.
This is a great forum.
Thanks again.
 

bilbo336

Member
Location
Durango, CO
Hey there Sparksaflyin,

I've read the responses but I am still not convinced. I also just got off of the phone after a long conversation with your boss and he isn't convinced either. Note that we are talking about UL Listed SE and USE wire which is not necessarily any THWN, XHHW, etc wire but wire tested and certified by UL to the service entrance requirements. I believe 230.43 by the word shall restricts you to the wiring methods listed. Also, Article 338.10 specifically grants permission for SE and USE to be used as service entrance conductors as well as 332.10 for MI cable, and 330.10 for MC cable, 326.10 for IGS cable. All of these same cable types are specifically mentioned in 230.43. None of the other cable types in Article 330 have that specific permission. The UL Listing for USE and USE-2 shows wire sizes up to 2000 kcm accomodating any industrial requirements for a service entrance. So far, I stand with my position.

bilbo336 (aka the client)
 

Smart $

Esteemed Member
Location
Ohio
Hey there Sparksaflyin,

I've read the responses but I am still not convinced. I also just got off of the phone after a long conversation with your boss and he isn't convinced either. Note that we are talking about UL Listed SE and USE wire which is not necessarily any THWN, XHHW, etc wire but wire tested and certified by UL to the service entrance requirements. I believe 230.43 by the word shall restricts you to the wiring methods listed. Also, Article 338.10 specifically grants permission for SE and USE to be used as service entrance conductors as well as 332.10 for MI cable, and 330.10 for MC cable, 326.10 for IGS cable. All of these same cable types are specifically mentioned in 230.43. None of the other cable types in Article 330 have that specific permission. The UL Listing for USE and USE-2 shows wire sizes up to 2000 kcm accomodating any industrial requirements for a service entrance. So far, I stand with my position.

bilbo336 (aka the client)
As stated by Sparksaflyin in the original post (hereinafter, OP), he wants to use XHHW copper in rigid conduit. See 230.43(3) quoted by me earlier so you don't even have to open the Code.

XHHW is a conductor type... not a cable wiring method that will be among Article titles. Conductors approved for 600V conduit wiring methods are mentioned in 310.10, along with additional requirements for conduitions of use, and listed in Table 310.104(A) [2011 NEC, formerly Table 310.13(A)], of which XHHW is one of them.

PS: Sparks' did not specifically say Rigid Metal Conduit, so also see 230.43(11)... and while you're at it, note all the conduit, tubing, and other types that can be used that are not cable.

PPS: Oh, BTW, as a professional of too many years to want to divulge, XHHW in Rigid Metal Conduit is by far a way more superior service entrance than SE or USE.
 
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jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Note that we are talking about UL Listed SE and USE wire which is not necessarily any THWN, XHHW, etc wire but wire tested and certified by UL to the service entrance requirements.

UL has a standard for service entrance Cable, they do not have a standard for service entrance individual conductors (other than direct burial).

The NEC recognizes SE cable as being different than individual conductors in raceways, but it accepts both methods as being suitable per 230.43.
 

ceb58

Senior Member
Location
Raeford, NC
Oh, BTW, as a professional of too many years to want to divulge, XHHW in Rigid Metal Conduit is by far a way more superior service entrance than SE or USE.
Smart is correct and if the OP is looking at this installation then it would be the Cadillac of the code compliant choices available. What size service are we talking about anyway?
 

hurk27

Senior Member
Hey there Sparksaflyin,

I've read the responses but I am still not convinced. I also just got off of the phone after a long conversation with your boss and he isn't convinced either. Note that we are talking about UL Listed SE and USE wire which is not necessarily any THWN, XHHW, etc wire but wire tested and certified by UL to the service entrance requirements. I believe 230.43 by the word shall restricts you to the wiring methods listed. Also, Article 338.10 specifically grants permission for SE and USE to be used as service entrance conductors as well as 332.10 for MI cable, and 330.10 for MC cable, 326.10 for IGS cable. All of these same cable types are specifically mentioned in 230.43. None of the other cable types in Article 330 have that specific permission. The UL Listing for USE and USE-2 shows wire sizes up to 2000 kcm accommodating any industrial requirements for a service entrance. So far, I stand with my position.

bilbo336 (aka the client)

To understand how to interpret the NEC and understand the rules and requirements one must understand that the NEC is a model code to be adopted as law where it is to be enforce.

As a law it is considered a permissive code, if it doesn't say it can not be used then it can, and is one of the most important things we much understand, other wise we can easily think it doesn't allow a wiring method just because it doesn't give exact permission to use it, this is wrong and a very common mistake that many make.

If we look at 90.5 and the commentary in the NEC hand book which is wrote by the vary people who also sit on the code making panels who wrote the NEC we will see that at times the code can make permissive statements but it does not mean this is the only allowed method:

90.5 Mandatory Rules, Permissive Rules, and
Explanatory Material
(A) Mandatory Rules. Mandatory rules of this Code are
those that identify actions that are specifically required or
prohibited and are characterized by the use of the terms shall
or shall not.
The Code uses two distinctive types of rules: mandatory
rules and permissive rules. Mandatory rules, characterized
by the terms shall and shall not, are covered in 90.5(A).

(B) Permissive Rules. Permissive rules of this Code are
those that identify actions that are allowed but not required,
are normally used to describe options or alternative methods,
and are characterized by the use of the terms shall be
permitted
or shall not be required.

Permissive rules are simply options or alternative methods
of achieving equivalent safety — they are not requirements.
A close reading of permissive terms is important because
permissive rules are often misinterpreted. For example, the
frequently used permissive term shall be permitted can be
mistaken for a requirement. Substituting “the inspector must
allow [item A or method A]” for “[item A or method A] shall
be permitted” generally clarifies the interpretation.

As we can see from above a permissive is only a statement allowing a method to be used for a purpose but not that it is the only method.

Now let's take a look at article 338.10 "Uses permitted"

338.10 Uses Permitted
(A) Service-Entrance Conductors. Service-entrance
cable shall be permitted to be used as service-entrance conductors
and shall be installed in accordance with 230.6,
230.7, and Parts II, III, and IV of Article 230.

All this is saying is SE cable is allowed to be used as service entrance conductors, what it is not saying is it is the only wiring method, as it can't be simply because it is only manufactured up to 4/0, what would happen if we had a 400 amp service? also 310.15 only allow SE cable to be sized from the 60?c table which will reduce its Ampacity when compared to other wiring methods.

Also in 40 years of installing services I have never seen a weather head made for conduit but also allowed to be used with SE cable, SE cable has it's own type of weather head that goes right on the cable, most all other weather heads will have three or four holes for use with single conductors.

Basically the NEC allows any wiring method in 310.104 that meets the requirements of location such as: wet location and if exposed to the sun, it would have to be sunlight resistant which is required in 310.10(C) and (D), and (D) allows us to even use a non sunlight resistant conductor if we use a sunlight resistant tape or covering over the exposed end subject to direct rays of the sun.

As a member of NFPA, and the IAEI who also has traveled the country sitting in on NFPA meetings with many of the code making panels members, I hope this helps clear up your misunderstandings
 

bilbo336

Member
Location
Durango, CO
pbazua - your comment doesn't make sense. If the UL Listing includes XHHW as an insulated conductor for MC Cable does that mean that all XHHW conductors are MC Cable rated? I think you are confusing insulation type with cable type. Also, UL tests cable for certain characteristics other than insulation characteristics. Insulation alone does not make a cable type.
 

bilbo336

Member
Location
Durango, CO
Thanks to the moderator for his or her thoughtful comment and shedding some light on this issue. I'm almost convinced (especially because we all know that AHJ is really spelled GOD) :)

What sparksaflying forgot to mention is that the client's company standards also require the cable used be UL listed and labeled for the application. I interpret this requirement to mean the cable or wire installed be rated for service entrance use. The only cable I can find that meets this requirement is USE, SE, MC, IGS and MI cable and certain sizes of UF cable and I cannot find any insulated conductors that do. Doesn't mean they don't exist, just means I can't find them. Also, I am not requiring sparksaflying to use RGS up the pole, only riser cable. He can protect it with U-Guard, as many utilities do.

This brings up another related question. If the NEC is happy with any method why do they go through the pain of defining uses permitted for certain applications and uses not permitted? Also, when does an insulated conductor become a cable? It seems to me cables have many properties that are specifically designed to adapt the insulated wires to the environment to which they are to be installed. Since a service entrance wire is one of the few application where the conductor is not required to have overcurrent protection at the source and it is could be subjected to very high fault currents lasting a relatively long time and it can be installed in extreme environments (temperature, water, various minerals, etc) it is not surprising that the NEC devotes many articles to its installation. I understand that RGS is an excellent way to install the insulated wires and I advocate its use. But when it comes to selecting the conductors I'm questioning if the code gives us direction on whether we should be using 75 degree C or 90 degree C, insulation type, etc. It seems to me these are important question that need to be considered by anyone designing service entrances.

bilbo336
"still confused but on a higher level and about more important things"
 

bilbo336

Member
Location
Durango, CO
Sorry - I don't mean to beat a dead horse but in my last post I said certain sizes of UF cable was permitted for service entrance cable. That is wrong - I misread the UL Listing info "Indicates cable for underground installation including direct burial in the earth. Maximum size is 2000 kcmil. Cable in sizes 4/0 AWG copper, aluminum or copper-clad aluminum 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." My bad.
 

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
Getting a conductor labeled for use in an application is difficult if you want that labeling on the conductor. The NEC allows many types of conductors in raceways. A service is permitted to be done with most types of raceways but not all. I don't have the UL books, but am curious if it lists "use in raceways" for the general conductor types of XHHW, THWN, RHW, etc.

You can use whatever temperature conductor you want (60, 75, 90C) as long as your terminations support it. Most terminations are 75C (and in under 100A rated things they may be only 60C). The only reason to go above 75C is if you have bundling or high ambient temperatures that require further derating of the conductor. Otherwise, you'll be buying a larger conductor that you need to if you don't go for the 90C insulation. The NEC is not a design manual. It is up to the trained designer to know the pros/cons of various insulation types, whether it is better to use larger 60C cables versus smaller 90C ones, etc. The code just sets minimum limits for safety.

The NEC must list the "uses not permitted" sinec you can do anything you want unless prohibited. The "uses permitted" I find annoying. As a previous poster showed, uses permitted shows a possible use, but not the only use and not the only solution to a situation. These can be helpful when inspectors make a common mistake and disallow something that is not actually prohibited. But I think fine print notes are a better solution for that and much of the uses permitted should go away.
 
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bilbo336

Member
Location
Durango, CO
I agree with suemarkp about the Uses Permitted sections - they tend to confuse the issue more than clarify. If you can do anything unless it is prohibited by the code, then why have a Uses Permitted article - a Uses Prohibited article should cover it. Also, notice that for the cables listed some of the Uses Permitted articles have the informational note "The ?Uses Permitted? is not an all-inclusive list." However, of the cables listed as permitted for service entrance use, only MC Cable has that same informational note. Curiouser and curiouser.
 

bilbo336

Member
Location
Durango, CO
Question for Hurk27

Question for Hurk27

I just re-read your response and it raises a question based on your answer - Article 230.43 is worded "Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods:" Based on your post it seems to me this article is telling it is mandatory to use the wiring methods listed and no other methods are allowed. Where am I going wrong? Sorry to be so thickheaded - it's been a curse all of my life.

bilbo336
 

Smart $

Esteemed Member
Location
Ohio
I just re-read your response and it raises a question based on your answer - Article 230.43 is worded "Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods:" Based on your post it seems to me this article is telling it is mandatory to use the wiring methods listed and no other methods are allowed. Where am I going wrong? Sorry to be so thickheaded - it's been a curse all of my life.

bilbo336
I'm not sure you are going wrong.. you didn't elaborate.

What wiring method(s) in addition to those listed would you even consider???

BTW, we are not limited to a single method for a single set of service-entrance conductors. For example, we may have a portion that is RGS, then continue, splice or tap the conductors in a wireway, and continue into auxiliary gutters... and meet the requirement.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I just re-read your response and it raises a question based on your answer - Article 230.43 is worded "Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the type of wiring method used and shall be limited to the following methods:" Based on your post it seems to me this article is telling it is mandatory to use the wiring methods listed and no other methods are allowed. Where am I going wrong? Sorry to be so thickheaded - it's been a curse all of my life.

That is definitely intended, as stated, to be a complete list. When it comes down to all of the various types of raceway listed, in addition to the "self-contained" options like SE and USE, that section does not say anything about what type of conductors (either wire or cable) you can use inside those raceways. That part has to come from the use restrictions on different types of wire as well as the limitations of any cable type you might for some odd reason decide to put inside the raceway instead.
 
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