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Joined: Feb 2004
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Hi,
If there is a pole 125' from a residence that has the main panel in the garage on a lower level and there is a main at the pole and a main at the main panel and there are three USE feeders to a pull box does the gec at the residence have to be in the raceway from the pull box to the main panel? The wiring must transition here to an inside wiring method..
I was planning to use a 3 conductor SER cable from the pull box to the panel and run the gec from the main panel to the ground rod.
I am asking because it is after the first ocpd.
Thanks for any replies
Mustang
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The only reason to put the GEC (Grounding Electrode Conductor) in a raceway would be to protect it from "Severe Physical Damage" or if it were smaller than #8. Code reference: 250.64(B)
George Little
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Why do you have a main disco at the pole?The GEC should run to the 1st main disconnect for any installation.
shortcircuit
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Hey Short Circuit, it's not uncommon to have the Service Disconect on a pole. They do it all the time in Texas and I've seen it even here in Michigan. The Service Disconnect and the meter for the utility is on the pole. I might add they have a Maypole type arrangement for the rural area and feeders run to numerous buildings as a standard installation. Makes it easy for the firemen to disconnect power ![[Linked Image]](https://www.electrical-contractor.net/ubb/smile.gif) [This message has been edited by George Little (edited 11-18-2004).]
George Little
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Hi,
Thanks for the replies. The pole and meter base ocpd combo (SQD) is set to provide temp power for the site until the main panel at the house is set. It is not uncommon to have a pole with a meterbase and a disconnect on it. Almost ALL trailer parks are like that and almost all farms will have this arrangement.
There is nothing wrong with it as far as I know.
George, wouldn't the GEC have to be in the raceway or cable if this is considered a sub panel? Seeing as how it is fed from the pole I was just curious if there was anything to watch out for. Just trying to confirm.
I was just verifying what I was thinking because you have to be careful after the first OCPD with the conductors.
Thanks for the replies.
-regards
Mustang
[This message has been edited by mustangelectric (edited 11-18-2004).]
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Joined: Jun 2004
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Doesn't 250.24 require the GEC to be installed at or before the main disconnect?
And I would consider it a grounding conductor if it is after the main ocpd combo meter base.
250.134b says that the grounding conductor be run with circuit conductors.
If this is not correct,where does the code allow a different arrangement?
shortcircuit
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Hi,
Have you ever seen an overhead SE drop with a EGC or GEC?
The first ocpd has a gec but no egc.
The GEC is ALSO REQUIRED to be established at the detached building or seperate service.
Correct?
-regards
Mustang
[This message has been edited by mustangelectric (edited 11-18-2004).]
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Hi Mustang...maybe I'm not understanding your first post. I thought that the USE feeders are installed from the pole 125" from the residense to a hand hole by the residense where you will make the transition to the main panel in the garage???
shortcircuit
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Joined: Jun 2004
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Hey George Little...I don't see disconnects on poles to much. Seems like it would be easy for vandals to shut down power to the dwelling.When I have seen them they are up high out of reach(8')...and are for something like traffic lights or telephone equipment.Are the disco you see out of harms way? What is a Maypole???I do understand that things are done differently throughout this great country of ours shortcircuit
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Joined: Jul 2004
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A maypole is a central pole where the service drop lands with the disco and meter that then gets distributed to other locations. I used to see that in state parks fairly often. The service pole would be right in the middle of several buildings with a transformer on it and the MV line on top. They looped down to the disconnect/meter Below the transformer there would be a series of drops going to the buildings.
Greg Fretwell
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Thanks fretwell, I didn't get a chance to respond. I was wrapped up with the issue about who could post an entry on this BB. I might add that it is still used in the rural area quite a bit and the incident of vandalism is not a problem. Maybe your average vandal is not comfortable messing with electricity
George Little
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Question: Does Type SER have a reduced size neutral like Type SE has? I have not researched the UL directory, but I think that it is 2 sizes smaller, and UL says is can carry the same current. Question: How does UL come up with this? Question: Is anybody here on the UL Council?
Joe Tedesco, NEC Consultant
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Around here SE can be had with a full size neutral and I have never seen SER with a reduced size neutral.
shortcircuit
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Same here short circuit- SER comes with three full size insulated conductors and a reduced size bare conductor. SEU is available with a reduced size concentric conductor that is sometimes used as a comon conductor (Neutral) and sometimes used as an equipment grounding conductor.
[This message has been edited by George Little (edited 11-20-2004).]
George Little
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I bolded the words I was thinking about. Anyone who wants a PDF file of the UL White Book for 2004 let me know I will send the link. SERVICE CABLE (TXKT)
SERVICE ENTRANCE CABLE (TYLZ)
This category covers service-entrance cable designated Type SE and Type USE intended for use in accordance with Article 338 of the National Electrical Code, NFPA70.
Service-entrance cable, rated 600 V, is Listed in sizes No. 14 AWG and larger for copper, and No. 12 AWG and larger for aluminum or copperclad 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 Type designation of the conductors may be marked on the surface of the cable. When used, this marking indicates that the temperature rating for the cable corresponds to the temperature rating of the conductors.
When this marking does not appear, the temperature rating of the cable is 75 C.
The cables are designated as follows:
Type SE — 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 — cables for underground installation including direct burial in the earth. Cable in sizes No. 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 National Electrical Code. 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.
Submersible Water Pump Cable — Indicates a multi-conductor 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 incl., copper, and 12 AWG to 4/0 AWG incl., 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 may also be surface-marked ‘‘Pump Cable.’’ The cable may be directly buried in the earth in conjunction with this use.
Cables that are acceptable for installation in cable trays are so marked.
Cables may employ copper, aluminum, or copper-clad aluminum conductors.
Cables with copper-clad aluminum conductors are surface printed ‘‘AL (CU-CLAD)’’ or ‘‘Cu-Clad Al.’’ Cables with aluminum conductors are surface printed ‘‘AL.’’
Cables employing compact-stranded copper conductors are so identified directly following the conductor size, wherever it appears (surface, tag, carton, or reel), by ‘‘compact copper.’’ Abbreviations of ‘‘CMPCT’’ and ‘‘CU’’ may be used for compact and copper, respectively.
Tags, reels, and cartons for products employing compact-stranded copper conductors have the following marking: ‘‘Terminate with connectors identified for use with compact-stranded copper conductors.’’
For termination information, see Electrical Equipment for Use in Ordinary Locations (AALZ).
Based upon tests which have been made involving the maximum heating that can be produced, an uninsulated conductor employed in a service cable assembly is considered to have the same current-carrying capacity as
the insulated conductors even though it may be smaller in size.
The basic standard used to investigate products in this category is UL 854, ‘‘Service-Entrance Cables.’’
The UL symbol on the product and the Listing Mark of Underwriters Laboratories Inc. on the attached tag, coil, reel or smallest unit container in which the product is packaged is the only method provided by UL to
identify these products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the name and/or symbol of Underwriters Laboratories Inc. (as illustrated in the Introduction of this Directory) together with the word ‘‘LISTED,’’ a control number,
and one of the following product names as appropriate: A service entrance cable that contains copper or copper-clad aluminum conductor(s) has the product name ‘‘Service-Entrance Cable’’; a service-entrance cable
that contains aluminum conductors has the product name ‘‘Aluminum Service-Entrance Cable.’’ edited to remove excess spaces and improve readability [This message has been edited by resqcapt19 (edited 11-21-2004).]
Joe Tedesco, NEC Consultant
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The "uninsulated conductor" in SER is the EGC. The neutral has always been the same size as the ungrounded conductors in the SER I have seen.
Greg Fretwell
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The "uninsulated conductor" in SER is the EGC. The neutral has always been the same size as the ungrounded conductors in the SER I have seen. That may be true when you are using SER for single phase feeders but when you use four conductor SER for three phase services that smaller bare conductor is the neutral. -- Tom H
Tom Horne
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
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This was touched on in a post a while back, and I think we figured out that 250.32 held the answers to this, and allowed two different methods. Not creating parralel paths to ground like egc, gec or metalic water line, would determine if you could do it in the way you described, and where the neutral was bonded. www.markhellerelectric.com/250.32.pdf
Mark Heller
"Well - I oughta....." -Jackie Gleason
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Joined: Jul 2004
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Tom I guess Mustang's reference to a residence got me thinking single phase. I suppose you can use 3 wire w/g SER for 3 phase service conductors but you better show me some engineering about what your anticipated L-N loads are going to be. If we are going to see any significant reactive loads on the neutral you are probably going to have to put in a larger <than phase> neutral.
Greg Fretwell
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