Asbury loop

[zachz]

Can anyone tell me where to find information on the Asbury loop. I am a lineman at Pacific Power and some on my co-workers are telling me it is best way to ground a single phase transformer. I disagree and also it is not our construction standard.

Thanks Zach

 

[MikeHalloran]

Not a clue.

Maybe someone here will know:

http://www.line-man.com

Mike Halloran
Pembroke Pines, FL, USA

 

[waross]

This is all I can find;

http://www.fs.fed.us/database/acad/elec/ed000107.pdf

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[MikeHalloran]

So it appears that on the planet PGE,
Asbury is an adjective,
and Fargo is a verb.
.. and we lack the correct dictionary.

Or
The leader from the note that references note 6 appears to be pointing to the corrugated duct, not the ground wire, as if it were asking the contractor to wrap the wire around the duct in some specific way, known as a 'Fargo to Asbury Loop'.

Or
The drawing was produced by a professional drafter like my friend Ralph, and not back-checked by the engineer who did the original sketch. I.e., the drafter couldn't read the chicken-scratches.
(Ralph was amazing; you could give him a pile of sketches on cocktail napkins and get back a beautiful E drawing in an afternoon. He was like a machine. Also as smart; your sketches had to be correct.)



Mike Halloran
Pembroke Pines, FL, USA

 

[mivey]

LOL
Mike, that is too funny. see my post here:

http://forums.mikeholt.com/showpost.php?p=1119044&postcount=3

 

[mivey]

BTW Mike,

I agree with you about good draftsmen being amazing. That work can truly be an art form. Pen & ink used to separate the men from the boys.

 

[zachz]

I have attached our single phase transformer connection. This is the connection I prefer but some of the lineman claim the mythical asbury loop connection is better. Basically they take our standard connection but add a tie between the H2 bushing and the X2 bushing. I see no point in this connection and think that it would adversely affect the transformer. I am just trying to find some facts to back this up our some actual facts about the asbury loop. If there is such a connection.

 

[mivey]

zachz,

I think someone at your place of employment is yanking your chain. The diagram you show is for a two-bushing transformer. With the two-bushing transformer, the H2 bushing could be connected the one of the primary phases or the primary neutral depending on the system voltage and transformer voltage.

With a single-bushing transformer, H2 is connected to the primary neutral. The primary and secondary neutral are bonded. X2 is connected to the secondary neutral. The secondary and primary neutral are bonded and that is essentially how you get the H2 to X2 tie.

You would have the same H2-X2 tie if the H2 of a two-bushing transformer were connected to the neutral.

But I don't think that has anything to do with the original diagram you posted.

As I said in the post I linked, "Asbury" must be a typo. It probably started out as a dictation of "as-buried" or some such reference. Fargo is a brand of connector and would mean to use a compression connector on the wire.

 

[schell44]

Fargo and Asbury are place names. The instructions are to tie into an existing ground loop. Fargo & Asbury could be street names, buildings, vaults, etc.

 

[mivey]

schell44,

I might buy into one of the primary loops being called the "Asbury loop" due to location. Also, you might want to clamp the ground wire to the concentric neutral.

The problem is that is makes no sense to name and isolate one primary as such. If you would bond one, you would bond any.

Some amorphous dedicated ground loop running from "Asbury" to "Fargo" is not likely either. Besides, you would not just loop the ground loop into a loop.

It is just a typo. Don't read so much into it.

 

[apowerengr]

I'm not familiar with the Asbury reference, searched several IOU spec books and did not find it either. As for bonding H2 directly to X2 this was (and is) a common practice by utilities who used bolted connectors. Run your #6 or #4 CU from the primary neutral through the H2 bushing connector to the X2 lug and on to the tank lug below the X2 bushing as one continuous conductor. OR Primary neutral - H2 - X2 - secondary neutral with an X2-tank strap and a tank lug-primary neutral bond provided redundancy for failure of any one connector. As noted Fargo is a manufacturer of various electrical connectors. Could Asbury be " as buried"? Some of these connections were modified with the advent of the side-opening vise-type tank lug connector.