tri-plex in conduit

[kingpb]

The service entrance cable in conduit does not have to have an insulated neutral. There may be other problems as mentioned by Iwire and others
but other issues aside, it should be deemed acceptable on that basis.

 

[dnem]

Since you are an inspector, could you please provide me the specific references in the code that allow this?

I went back to 1993 Handbook and see that it was allowed at that time. But according to NEC 2005, I interpret all references to SE cable, that it is no longer allowed to be run that way. I need justification, Thanks.

Sorry, I somehow missed this question for the past week.

Where SE can be run without protection is open to opinion.
338.10(A) leads you to 230 Part 4 which includes 230.50(A).
"Service cables, where subject to physical damage, shall be protected by any of the following:

In my department, the chief has decided that subject to physical damage would be where it is subject to vehicle damage such as areas where a driveway comes right up along side of a section of the house and the service conductors are run in that area. So the vast majority of the installs don't need to be in conduit.

Ask your local inspector how he defines that phrase.

David

 

[dnem]

Wonder what he would have done if the riser had URD or USE or triplex in it???? If we could get a determination, sure would save some cash on the installation, and give us a use for the left over small pieces of service wires we all have laying around.... Dennis in NM

USE can be used in the riser for an overhead going from the meter to the weatherhead.

This is from the Handbook page 362 under 338.1

bold type added by me

"Type USE or USE-2 --- Indicates cable for underground installation, including burial directly 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 Code. Types USE and USE -2 are not suitable for use in premises or above ground 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."

338.10(A) references 300.5(D)
300.5(D)(1) says that the conductors must be in a raceway when emerging from grade. So where on the line side of the service main are the conductors exposed to sun ? Sticking out of the weatherhead is the only place.

So USE is suitable for both underground and mast service entrance conductors.

David

 

[Todd A Arnold]

Use of tri-plex in conduit

Use of tri-plex in conduit

Article 396 in the 2005 Nec references tri-plex not being used in conduit.

 

[kbsparky]

Article 396 in the 2005 Nec references tri-plex not being used in conduit.

Can you cite the specific section of article 396 where this is stated? I can't seem to find any reference prohibiting the use of conduit in article 396....(not that I would install it anyways...)

 

[amptech]

Maybe it is a "local" term, but duplex, triplex and quadplex around here refers to ACSR type cable used for overhead service drops. ACSR is a factory-assembled aerial cable utilizing a bare conductor(the neutral) with one or more insulated conductors twisted around it. The bare cable is aluminum with steel re-enforcing strands. Hence the ACSR(aluminum cable steel re-enforced). Its use, I believe, is covered in Article 396. I have never seen any markings on the conductors of ACSR but the reel the supply house pulls it off of has a tag that says "Messenger Supported Wiring Type ACSR Cable". Underground Triplex or quadplex is referred to as URD tri or quad.

 

[tom baker]

Most triplex is not UL listed, and can't be installed in a raceway
For a overhead feed to a outbuilding one could use quad plex.

 

[peter d]

USE can be used in the riser for an overhead going from the meter to the weatherhead.

So USE is suitable for both underground and mast service entrance conductors.

I disagree. The language is crystal clear. USE can only be used above ground between the point it emerges from grade to the terminals on the service equipment. That's it. I don't see how you can allow it anywhere else.

 

[JohnE]

I disagree. The language is crystal clear. USE can only be used above ground between the point it emerges from grade to the terminals on the service equipment. That's it. I don't see how you can allow it anywhere else.

Some USE is also rated XHHW, I believe. And this USE is often referred to as "triplex" in my area. Also referred to as "URD". Also as "sweetbriar", "stephens" and some other names which indicate the type and size which is how my supplier refers to it.