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Joined: Nov 2000
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There are KO's on the disco and the meterbase sides of the GRC Nipple. Do the locknuts on one end still comply?



[This message has been edited by sparky66wv (edited 04-09-2001).]


-Virgil
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Joined: Oct 2000
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66'
i'm confused here!
is this a continuos piece of #4, or are you just using small pieces to bond ???

[Linked Image]

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The grounding locknut doesn't fly out here due to the fact that there is not a solid path from the washers to the can = bushing. The ground clamps mentioned above(1/2" conduit to rod or pipe) are available from Weaver/Blackburn as a #JP-12, JP-34, etc. They've got a conduit hub, and a PASS THROUGH lug (not just a wraparound screw w/ washer) for the larger sized GEC's. 1/2 of the clamp can be reversed for rods, and they'll fit a 1/2 through 1 water pipe. Made of bronze.

[This message has been edited by electure (edited 04-10-2001).]

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Sparky...

Here goes...

The GEC is one continuous piece between the neutral/ground buss in the disco and the two ground rods.

However, the "bonding wire" for the nipple is a short piece to the neutral/ground buss, it isn't there to ground anything (defining 0 volts), the bond screw does that, but it is there to assure ampacity on the nipple through the KO's in case of a ground fault. Should I put this in one continuous piece from the Ground rods to the nipples to the PVC water pipes (a little joke there) to the grounding bushing and out to eveyone's house in the neiborhood? OK so I'm going extreme here but bring on the flames...

BTW, if this is true than there are zero houses in Greenbrier County that meet code.


-Virgil
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66'
well 250 is the flame-daddy of all articles.
one bone of contention is in the fact that the entire article has been reshuffeled, so there is a continuos line , so one cannot use the glorified line to decipher 96' to 99' changes.
[Linked Image]
i think i understand your configuration now, thanks!

let me ask a Q

does 250-142 allow the noodle in the meterbase, which i take is integral to the enclosure to do the job of 250-94???

isn't that noodle a "dual-usage" conductor up til the main disco??

[Linked Image]

burn baby burn!

[Linked Image]

[This message has been edited by sparky (edited 04-10-2001).]

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Sorry Man... I was in a foul mood this morning (on my tenth workday in a row plus two gigs this past weekend...and to think I was complaining of not enough work two weeks ago...)...

As you stated in your Q, the meter base is bonded to the neutral, as per 250-142, and the GRC Nipple is bonded on the disco side, so I suppose that it is electrically continuous with only one grounding bushing, although the fault current would have to "backfeed" to the neutral buss, to the neutral conductor and finally back to the meterbase... depending on what size OCPD the pole-climbers have protecting the Xformer, all this rube-goldberg connecting could have a significant resistance; just seems better to have the nipple bonded to the meterbase side straight to the unused lug on the neutral bar... Just a theory...


[This message has been edited by sparky66wv (edited 04-15-2001).]


-Virgil
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66', it's cool....
the bonding a both ends was an angle about GEC's as applied to your scenario 250-64(e),if you had been allowed to pass it in one piece thru to the meterbase, our local utility allows this!

250-142 allows you to connect the GEC anywhere up to the service head! It does not directly come out and say this, God forbid any clarity that simple should exist in the NEC! It implies this by way of allowing a dual-usage conductor, which in itself could be run thru the GRC and used to bond it on the way to the panel. At least the way i read this.

Current will follow a parrallel path thru the bonding jumper in the MDP,thru the panel enclosure, thru your GRC, to the trans as well as thru the noodle.
[Linked Image]
So how does the intent of 250-6 NOT get violated in every service installation?
[Linked Image]
Of the GEC, EGC , and bonds, i'm not as sure about what item does what job anymore, i don't mean code wise, i mean the hardcore theory.

Case in point;
The Utility here, as many do, tie all the X-formers noodles to a pole ground AND the high side noodle, one big happy ground throughout the line extension covering miles... [Linked Image]
I'm not clear as this is an asset or liability in terms of outside influences.
Except when they get to a dairy farm, then there is no pole ground, and a isolated noodle at the trans!!!nothing on it but one line to the farm!
The theory being that only ONE point reference (noodle to earth)is, and works best.....hell we gotta keep them cows happy!
So why can't the same hold true for any other installation????It seems the NEC is bent on having us install parallel noodles!
[Linked Image]
other threads with individuals well versed in this area have me questioning all the heavy 2-sylable programming out trade seems to be let loose with
[Linked Image]
OH!, i remember those 3 night-in-a-row gigs!I don't miss em', but i'd still like a crack at that 6-string of yours, what make is it??


[This message has been edited by sparky (edited 04-10-2001).]

[This message has been edited by sparky (edited 04-10-2001).]

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It's a Carvin, model number unknown cause Carvin hand makes them to special order. It cost me $1200.

The EE wanted NO #4 bare in his meterbase, period, whether it was a GEC or an EGC. Only the six 4/0's allowed (3 wire line and load).


-Virgil
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Quote
Sparky said:
It seems the NEC is bent on having us install parallel noodles!

Perhaps parallel neutrals would help to cut down on lawsuits resulting from "240V series circuit" "meltdowns" from lost neutral connections?

Just a thought...

[This message has been edited by sparky66wv (edited 05-04-2001).]


-Virgil
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Quote
Originally posted by sparky66wv:
While installing a 200A meter base and tightening the 2"x 6" nipple, the KO came apart and (eccentric type KO's) so I made a call to the PoCo engineer and asked if I could use reducing washers as long as I bonded with a grounding-type locknut (the ones with the screw). He had no problem with having reducing washers but did not want any #4 copper in his meter base.

What happens when the AHJ busts me for noncompliance with 250-94? Should I get an affidavit from the PoCo engineer?

Would it be OK in this case to use a lay in lug type bonding bushing and run the neutral through it on the way to it's terminal in the meter base.
--
Tom


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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