URD for Service

Status
Not open for further replies.
1793

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
I have been looking over the URD topics listed here over the past few days and I would like to ask a question.

I have a service to install. I went to the?supply house and asked about the types of direct burial wires. I was shown a 4/0-2/0 AL twisted URD with a listing of "XLP". I was told that this is sold in great numbers to others for 200 amp services.

My question: I am planning on using Sch. 80 up to the meter base. This only about 6' of protective conduit. Then a short nipple between the meter and the panel. I'm having trouble determining between 2" and 2-1/2". Do I use the properties in Table 8?

Any help will be greatly appreciated.

Norb

[Edited for explanation of situation]

[ April 17, 2005, 04:29 PM: Message edited by: 1793 ]
 
Re: URD for Service

I'm going to "answer" your question with a question and maybe someone else can tell us if im right or wrong. If you have a service lateral to the meter, is the service point at the meter thus making the service lateral design not fall under the NEC? I dont have my book handy so i cant try and confirm that at the moment. Regardless, you may want to check with your utility, as they sometimes have specific pipe size requirements.
Regards
Ethan
 
Re: URD for Service

If its under 24" then its a nipple and the rules are different, see note 4 in Chapter 9 tables. What I would do is use the largest size KO on the meter, if its 2 1/2" use a 2 1/2" nipple.
 
Re: URD for Service

Thanks everyone. I have purchase the wire and I have gone with 2-1/2" Schedule 80.

The wire is marked as follows:

4/0 RWG AL XLPE USE-2 Sun-Res.

I have yet another question as to the markings, what does the "2" after USE stand for?

Norb
 
Re: URD for Service

Norb,

The suffix -2 means that it is rated for 90 degrees C wet or dry, without the marking it is rated for 75 degrees C. Check out the white book for General Information for Electrical Equipment put out by UL(the new testament to Electrical Bible).

Jim
 
Re: URD for Service

Look at note 4 to table 310.13 for the explanation.


"4 Listed wire types designated with the suffix "2", such as RHW-2, shall be permitted to be used at a continuous 90 degree Celcius (194 degrees Celcius) operating temperature, wet or dry."
 
Re: URD for Service

If you have a service lateral to the meter, is the service point at the meter thus making the service lateral design not fall under the NEC?
Click to expand...
That is a true statement as long as the service lateral will be owned by the electric utility. Most of the time, the installer of the lateral also remains the owner and the lateral must follow the requirements of the NEC. :D
 
Re: URD for Service

The last time that I did this application I used 2.5 inch schedule 80 for the straight lengths all the way from the padmounted transformer to the meter socket. The trench was right in a prime area for planting trees, which I suspect happened to the old service. At the time the 90 and 45 degree bends had to be schedule 40. I just found out that Cantex makes factory bends in schedule 80 PVC.

Turns out that it PAID to use 2.5 inch conduit because the wire pulling was that much easier. If I cannot hook up a forklift truck or wire pulling winch to pull in the wires a larger conduit is very prudent.

Also, please take a close look at chapter 9 fine print note #2 regarding jamming in conduit bends.
 
Status
Not open for further replies.
Top