Anyone that might know??

[rcdallas]

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[MI-Lineman]

That's cause your middle phase (witch in Detroit you can't rely on being Y;)) is the return! Here they would be on a cluster on the same pole but the center phase isn't always deadended like the other 2!

Hope that helps! In a Delta system one of your phases can be the return!

[rcdallas]

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[topgroove]

Thats a 4800 delta primary . the regulators are one the outside phases because engineers use to think regulating the outside phases will adjust the middle phase all by itself. Flawed thinking! now we hang three regulators. I've built about thirty banks like that only we hang all three in a bank as long as they're 167 kva and below.

[MI-Lineman]

Damn it, you done jacked up all my thinking!!!

Alright, so if you look at a sine wave, A will be up top B in the middle, C at the bottom...

Is that why B would be the return?

I'm not sure what you mean by "center phase isn't always deadended like the other 2"

Also, I guess on a delta you can only regulate 2 of 3 phases?

Let me throw this at you, every transformer I came across at DTE would be wired delta on the high side, and only one cutout to a primary bushing, the other side would be nothing more then a hot top sitting on a tap saddle.

Why would they not use two cutouts? I would think you'd want to fuse both sides.

Gish! You're killin me here!:D I think you're on with the sign wave thing but I gotta think some more? In Detroit where I worked not only was it Delta but it was looped! That means NO REGS, NO BOOSTERS, NO LCPS (on the feeder circuits!), NO OCRS, BLAH, BLAH, BLAH! YOU KNOW WHY? IT'S LOOPED!!!!! IF YOU PUT A REG ON A LOOP WHAT'S GONNA HAPPEN!!:eek: SAME WITH BOOSTERS! CAN'T FUSE A LOOP KINDA WON'T WORK WELL (the loop that is!) SO NO LCPS IN THE CIRCUITS (course we had switch points between circuits and outta the subs!). SAME FOR OCRS!;) AND SO ON!

As for the center not ALWAYS being deadended....if your usin it as the return you won't need to have a bypass! Now here at C.E. they have a spec in their book for both? I'll have to look again for why when I get back from Cedar Point next week! OH YEAH!!! SORRY THAT'S ALL THAT'S ON THE BRAIN RIGHT NOW!:D

As for the transformers havin only one switch you might want to take a closer look? Those are B (or power pots) usually! The 120/240 bank is used all over that place but the tubs are spread out all through the city and banked together! Why? I have no frickin clue! But anyways the A or lighter pots ARE (or were when I was there!) fused on both sides! We always direct tapped the b!tch leg side I think??? Damn it! Plus the sec. legs comin out of the tubs are fused!!! I haven't had to mess with that stuff in a long while!

Think West Coast deals a lot with Delta? Plus Edge or Door would know? I'm goin to the NASCAR race tomorrow with the Daughter and then on to Cedar Point!! If no one gets back to ya by Friday (I doubt that'll happen!) I'll get my notes outta my locker at work!!!

[MI-Lineman]

Thats a 4800 delta primary . the regulators are one the outside phases because engineers use to think regulating the outside phases will adjust the middle phase all by itself. Flawed thinking! now we hang three regulators. I've built about thirty banks like that only we hang all three in a bank as long as they're 167 kva and below.

That's right on!! C.E. and I think Detroit use 3 pot banks of'em! That's definitely not a pic from Detroit! Looks to clean and new!:D

[topgroove]

Damn it, you done jacked up all my thinking!!!

Alright, so if you look at a sine wave, A will be up top B in the middle, C at the bottom...

Is that why B would be the return?

I'm not sure what you mean by "center phase isn't always deadended like the other 2"

Also, I guess on a delta you can only regulate 2 of 3 phases?

Let me throw this at you, every transformer I came across at DTE would be wired delta on the high side, and only one cutout to a primary bushing, the other side would be nothing more then a hot top sitting on a tap saddle.

Why would they not use two cutouts? I would think you'd want to fuse both sides. on 4800 delta when one fuse blows on a tub theirs zero voltage accross the primary coil. its an open primary coil.

[bones]

http://books.google.com/books?id=wiv1tuMDbTEC&pg=SA3-PA72&lpg=SA3-PA72&dq=%22two+voltage+regulators%22+delta&source=bl&ots=Xw2oIPrTMe&sig=xOZpGBa4Mj0e_9RaX2Ej4VusyqE&hl=en&ei=2z4UTJL2G4P6lwfggOXrDA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CBsQ6AEwAg#v=onepage&q=%22two%20voltage%20regulators%22%20delta&f=false

[rcdallas]

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[rcdallas]

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[rcdallas]

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[rcdallas]

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[MI-Lineman]

Never saw anything on a loop system for a delta with no line devices and such, then again I don't know shit about delta. Nobody down here where I'm at can explain it to me, let alone any instructor I have can tell me enough about it. I know we have a real small section way out in east texas that's 2400 delta.

I think I might of seen some banks from what you described with being on separate poles along with the secondary having fuses.

Every time I have went back to Michigan and seen the stuff DTE has, like I guess Zig Zag transformers to make a neutral and step up transformers EVERYWHERE I just can't figure that place out.

Can't really stop and look real good at all the equipment without someone thinking I'm up to no good...

Have fun at Cedar Point, ride the magnum with your hands up in the air. eek:

First off being Delta doesn't really have much to do with being looped! You can have Delta that's not looped! In fact here at C.E. they have a bit of 12K Delta (not in my area though!). I think Detroit's theory (BELIEVE IT OR NOT!:eek:) was if you lost a phase in the circuit it wouldn't interrupt as many customers! I KNOW! YES IT PROBABLY KILLED A FEW! Definitely their dogs!:rolleyes: Had to shovel a few mutts away from the pole to get up it! Plus I think being looped helped with load issues!

You just wouldn't have FUSED LCPs on "feeder" circuits! Wouldn't work! They did have lateral radial circuits down there but not many where I was at!

SECOND......THE MAGNUM????:rolleyes: WHEN'S THE LAST TIME YOU WERE THERE???? THEY GOT RIDES NOW THAT MAKE THAT OLE-TIMER LOOK LIKE A CARNIVAL RIDE!!! The daughter and I went on all of them includin the "Millennium Force" (310ft with a 300ft drop-93 mile an hour average) and the "Top Thrill Dragster" (420ft high-120 MILES AN HOUR, YES 120 MPH-a 6 sec. ride only!!):cool: AND SHE'S ONLY 9!!!

Spoiled the sh!t out of her! Went to MIS then The Point, stayed at the Breaker hotel right on sight, AND went to Soak City!

THAT PLACE IS FREAKIN AWESOME!!!!

[rcdallas]

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[Trbl639]

We had some UG Delta in remote Alaska........generated 2400/4160 and then run approx a mile to the POL site...anyway it did not get buried before a winter storm, and it was just laying in a shallow ditch covered by several feet of snow........one leg was grounded, and at the powerplant, we had Ground lights on a panel, so if you got or started to get a ground on another phase, a second light would light up.......we got a second light and had to kill the line and try thumping it to find the 2nd ground...........anyway, when we found it, all 3 phases of the UG had No insulation/jacket nothing on them for approximately 6 inches....and it was still Hot.........wish I still had the pictures, but it was the damnest thing I had ever seen!!!!!!!

[MI-Lineman]

Well I won't hate ya but damn I started somethin now!!! Uh? Where to start? Well first I've been gone from there over 9 yrs and I just found out from a newer hand who topped out down there a few yrs ago they now put the arrestor grounds on a separate ground and I believe rod? I know he said they had screwy voltage problems but I'll have to ask him again? Let me write that one down....here....OK NEXT....OH I jumped around....the tree idea I'm not sure....hmmm...at any lower voltage, wye or delta your "LCPS" if there are any (LOAD CONCENTRATION POINTS-there's another answer) are fused higher right? That inverse relationship tween voltage and amps! So the phases tend to burn longer! Our 14.4 will trip if the smallest damn GREEN branch or limb hits it! Higher voltage/lower amp rating! Look at companies tree trimmin, I know our 14.4 circuits get more attention then the 4.8 and also you'll see the trees burned off at the phases! As far as Delta goes, sure a phase will burn through a limb or damn near lay on it without having an issue! It's when one of the other phases goes to ground your troubles start!:eek: Plus remember on a loop system there usually is no LCPs or fuses or Line devices so either the wire (which in Detroit was tough old copper on the old Delta) or the tree is gonna give! There may be more to that but that's what the "Theory Smart" guys are for like Top or T-man and a few others!

OK now the rod issue (don't worry either this is fun right after I get back from vacation!:rolleyes:) if that is the "narrow backs" code then I wouldn't pay much attention here to it! Their inspectors here usually have no clue what their lookin at no more than the people writing the rules do! The electrical code is actually 10' apart for them! You gotta remember they're dealin not only with inferior soil conditions (which vary all across this state!) but it's recent fill or disturbed soil! We're supposed to drive a minimum of 2 18" away from the pole until we reach 25 or less ohms on new construction or 50 or less on existin! Every damn crew but one I've worked on here AND in Detroit throws one rod in the pole hole and couldn't tell you where the ground rod tester even is!:confused: I hate that for the fact you put your life in the hands of those rods and grounds!

In Detroit we didn't get the opportunity to trouble shoot much as they had their own hands do that and I gotta say I met a few and I wish they were on this site cause some of them were Albert Einstein with a set of tools!! Damn good Lineman! But we had a few times where a cust lost their neutral and yes there was imbalances like normal and other times their basements would start floodin cause their old corroded water pipes tried being their neutral and ground!

Here we test ground rods and repair as needed. We just find ones over 50 ohms on existin construction and add new ones! Every time I change ANY URD equipment out I have to beg to drive two new rods cause as old as the equip is you can usually pull out the rod by hand and it's only a foot down cause it's ate up to a point! Have had newer 14.4 switch gear burn up only to find the old rod laying in the bottom of the hole? WHY YOU WOULDN'T CHANGE THE ROD WHILE THE CABINETS OFF IS BEYOND ME? STUPID STUPID STUPID!!!

So now you want some light shed on the return current for Delta?? That's about all I know is the "layman's" explanation? I've also said that before on here I think? I can, however think some more and get back to ya! First let me put this fire out tween my ears!:eek:

[rcdallas]

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[rcdallas]

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[wtdoor67]

I was gonna call you R.C. "transformer" Dallas, but now I think it's gonna be R.C. "Delta" Dallas. Yeah that'd be better.

Yes you can operate a Delta system with one leg grounded. In wide and wonderful Wyoming where I worked we had about 3 small subs that were 7200 grounded Delta. A 3 pot, or a 2 pot bank only needed 2 cutouts and 2 arresters as the third wire was grounded. Draw yeself a picture. Now a single phase line in this system looked just like a single phase wye line, unless you knew better. Grounded phase was put in the neutral position and the ungrounded phase on a ridge iron.

On an ungrounded Delta system you can ground one phase if you need to periodically. Have done it many times in cutovers and other stuff. The only kicker is to make sure it doesn't have a ground on any other phase. Best do it with a shotgun stick.

Just having a cut groundwire is not gonna kill little Johnny. Only under precise conditions, which are rare. Besides all those groundwire mouldings etc. get knocked off regularily by everything.

Topgroove ought to up to speed on this Delta stuff as I think he's a troubleman who works on it all the time.

Get that damn book I recommended and start studying.

Delta we gonna teach you about this Delta stuff and probably learn something ourselves.

Don't stop being curious untill they put dirt in your face.

[Edge]

On an ungrounded Delta system you can ground one phase if you need to periodically. Have done it many times in cutovers and other stuff. The only kicker is to make sure it doesn't have a ground on any other phase. Best do it with a shotgun stick.

Don't stop being curious untill they put dirt in your face.

Absolutely!!!! especially the last part!!! prolly why old shits like us still dig this site regardless of it's "ahem" radically political most prolific poster...

you take 4 or 5 or 7 years to top out and now your a full blowned GD JLineman... then ya take 5-10 more years to really become that...and you can stay there or you can keep diggin for more... keep pushing yourself to be more...

or you can just sit on your laurels and be half assed yesterdays linehand... up to you I reckon...

Ok...that brings up another thing I thought of.

"Say a wye-delta 480 ground leg bank, you have a grounded hot phase... it makes me wonder if on any delta primary if they ever use a grounded phase...ground it back at the substation.

Yay or nay?"

yeah they do in exactly the types of cases 'doors all ready explained... done a ton of those cut overs as well...

but it gets bigger than that Delta (I like that handle Danny)...next time your working near a transmission corridor or at a sub feed by transmission... look up to the big sky bubba....

most transmission lines are corner grounded... usually 69kv and up... theres a lot of y transmission stuff out there usually 34.5 and 42 and such but most of us call that "sub-transmission"... and there's some DC 'mission out there too... usually grid tyes and what not... but that's for another thread I reckon...

keep diggin...

Mi said something about Albert Einstein with tools...

well one of my favorite things Einstein said was simply this

"question EVERYTHING"

For what it's worth...

Edge

[MI-Lineman]

Hey R.C. like Door says the down ground BACK WHEN I WAS THERE was covered with wood molding cause the "Locals" would steal the bare #2 right off the pole! Yeah it's always a possibility to have a serious issue when you put yourself in series with a neutral but at the time I was there it was mainly a secondary neutral which was looped and bonded at every pole, to every trnsfrmr ground, house ground rod, and water line! I'll never tell ya to do somethin unsafe but cuttin the neutral open there was never an issue and done every day without consideration of customers loosin their neutral! ONLY ON THE DELTA NOW!

Also, you might have misunderstood me when I talked about throwin rods in the pole holes and not testin resistance? The guys in Detroit, well contractors anyways:o always threw them in the pole holes too! That isn't right and isn't being a GOOD LINE HAND!!!! DO IT RIGHT!!!

Now! To add a little more confusion to the groundin thing I hear now Edison requires a separate ground for arrestors and anything primary related! Somethin about crazy voltage problems? OH DOOR, EDGE, TOP??? A LITTLE HELP?? So now I guess I wouldn't go cuttin a ground and givin her a yank if the chance you have a bad or weak arrestor attached to it or even a famous broken porcelain switch bleedin on it! Remember, the more rods thrown into a damn pole hole instead of drivin in THE BETTER YOU LOOK TO CURRENT AS THE PATH!!:eek:

Hey don't ever worry about askin for info! I'd rather you ask then assume and get hurt! I definitely don't know everything AND NEVER REALLY WILL but I ain't afraid to ask those who do!!! Plus it's helpin me remember sh!t!:cool:

[climbsomemore]

Regulator installed on delta systems are usually installed on just 2 of the 3 phases in the feeder.

If the first regulator is installed using "A and B" and the second is connected to "B and C" (or whatever you named phases in your neck of the woods "XyZ etc")... B is regulated by default - as it is common to both the regulators.

If MI lineman digs around in the CE standards book for you... (and my crusty memory serves) they did have a standard that used 3 regs as opposed to the cheaper 2 reg schemes they usually installed.

Old Delta Subtations had a lamp on the board that would indicate a grounded phase in the feild. The station operator go out on the line and find the ground (or get someone to do this) and clear the fault.

Molding on ground wires. On old delta systems... a made ground was installed to get a ground reference for the transformer neutral and service neutral. Another ground rod and down ground was installed to bond and ground primary equipment to--- transformer tanks and arrestors.

Those two grounds operate with some potential difference between them. A molding was installed so people could not contact and bridge the difference between the two ground schemes.

[Trbl639]

Regulator installed on delta systems are usually installed on just 2 of the 3 phases in the feeder.

If the first regulator is installed using "A and B" and the second is connected to "B and C" (or whatever you named phases in your neck of the woods "XyZ etc")... B is regulated by default - as it is common to both the regulators.

If MI lineman digs around in the CE standards book for you... (and my crusty memory serves) they did have a standard that used 3 regs as opposed to the cheaper 2 reg schemes they usually installed.

Old Delta Subtations had a lamp on the board that would indicate a grounded phase in the feild. The station operator go out on the line and find the ground (or get someone to do this) and clear the fault.

Molding on ground wires. On old delta systems... a made ground was installed to get a ground reference for the transformer neutral and service neutral. Another ground rod and down ground was installed to bond and ground primary equipment to--- transformer tanks and arrestors.

Those two grounds operate with some potential difference between them. A molding was installed so people could not contact and bridge the difference between the two ground schemes.

We had the same thing.............if we had one light on the board 'lit', we were fine......if another on the board started flickering, we went to looking, cause something was fixin to happen!!!

Built many an open-delta 120/240 or 240/480V banks for irrigation wells that had a grounded leg on em...........okay, just as long as you grounded the same leg on the bank and the same leg at the weatherhead or in the meter can..........Farmers and electricians found they could get unmetered voltage, if a metercan was blanked off (no Meter) and the bank was still hot.........so we started grounding all of those banks so they couldn't get free juice anymore..............

[rcdallas]

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[rcdallas]

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[rcdallas]

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[rcdallas]

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[MI-Lineman]

Regulator installed on delta systems are usually installed on just 2 of the 3 phases in the feeder.

If the first regulator is installed using "A and B" and the second is connected to "B and C" (or whatever you named phases in your neck of the woods "XyZ etc")... B is regulated by default - as it is common to both the regulators.

If MI lineman digs around in the CE standards book for you... (and my crusty memory serves) they did have a standard that used 3 regs as opposed to the cheaper 2 reg schemes they usually installed.

Old Delta Subtations had a lamp on the board that would indicate a grounded phase in the feild. The station operator go out on the line and find the ground (or get someone to do this) and clear the fault.

Molding on ground wires. On old delta systems... a made ground was installed to get a ground reference for the transformer neutral and service neutral. Another ground rod and down ground was installed to bond and ground primary equipment to--- transformer tanks and arrestors.

Those two grounds operate with some potential difference between them. A molding was installed so people could not contact and bridge the difference between the two ground schemes.

Yeah! The three tub set up is shown on a platform only! Was that weight issues Climbsomore? That's what I was told!

Detroit didn't have separate grounds until recently! The hand that told me that worked in the thumb and they were installin the separate grounds to existin equipment. In the city itself with the oldest of old there was no separate ground? Everything was tapped on the same grounds. Sh!t When I was there we were goin around addin tank grounds cause the older tubs didn't have any at all!:eek: That place is a different animal for sure!

Hey RC me and another former Detroit hand decided Detroit only used the 2 reg spec! Where I was there was none! Again it was all looped! He worked on a few circuits that were apparently radial! We're still goin back and fourth on why or if and what trnsfrmrs were direct tapped? I still say it was the B pots on one side only? In-fact I know for sure the lighters (or A pots) were all fused at each high side bushing! They had them damn old asbestos Katos (Spelling??) and porcelain bayonets! I won't forget those!

[rcdallas]

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[wtdoor67]

The used books I found were on Barnes and Noble on line, not at some book store like maybe Dallas,Tx. The time I looked, they had several of those books used.

The 7200 grounded delta I worked on used pots marked 7200/12470, of course double bushing on the high side. Or 12470/7200, single bushing. The same old pot used in your Wye systems. The only cutover we did was from delta to wye.

Yes we used 2 grounds and 2 ground rods. One alone on the arresters and one connected only to the pots grounds and the service. This was on any phase to phase connected bank or pot wheather a delta or wye system. I think they did this the latter part of the time I worked for them. At PSO in Okla., they just used one ground I believe on the 2400 delta. All engineers have different ideas. They just ain't consistent. Also different districts in the same power co. have their own little hen house ways. You just have to do it "the way we do it", wherever you are.

If you get a chance to work on any cutovers, do it. They're probably the best learning experience in distribution for understanding most of the things that go on. At least I thought so. Do a couple of cutovers and you'll be a transformer whiz. If you can do a combination reconductor and cutover you'll be even slicker. They'll probable change your name to "slick" Dallas instead of Delta or R.C.

[topgroove]

for those of us who work on delta primarys Two seperate ground rods are very importand. The ground rods should be at least eight feet apart. If you can put the down grounds on seperate poles even better. You've got to keep the lightning protection seperate from the customers neutral. any strike on the primary directs all that energy straight thru the customers mains if they're conected together.

[climbsomemore]

but as you know .... 'return on investment' is everything to the mob at Jackson.

You get "ok" regulation with 2 units. You could spread 3 regs out on three poles in a row too... but 3 costs a third more.

Some of the old delta towns I worked around had a "neutral" strung block to block... but it never went back to the substation ground grid. It was just a buss that was grounded to earth. Theory tells us that all current want's to return to the source... and when we create a ground at the transformer pole that's as far as it goes.*ok I lied--it will travel in the earth till it returns to the generator* If you ever get to Sturgis Mi... it was built like that in many blocks... and the neutral was taken to the subs when the conversions took place.

Corner grounding delta secondary... you can place as many "grounds" as you want on one phase of any delta system... get a ground on either of the others... a short circuit will travel through the dirt and blow fuses.

Corner grounded delta secondary is big in the oil patch and on farm irrigation... years ago they found that having a phase bonded would make motor protection fuses more reliable. To further muddle the issue- Consumers Energy calls an accidental secondary ground a "power ground"... took me about 2 years to figure out what the fluck they were talking about.

The old substation boards... there was a light for each phase... if the lamp lit there was a ground on that phase. Byron had some old model T era photos on this website of men and equiment checking for circuit grounds.

MI Lineman...that "split neutral" you guys make for dairy and livestock farms is simply isolation of the "secondary neutral" from the grounds on the primary arrestors and tank grounds. They put a little LA between the two ground schemes to tie them together if they have to carry an over voltage to earth ... that limits a possible flashover between the down grounds. The idea is if you divorce the secondary return current from the y system neutral you can limit any circulating currents from the power line to any bonded metal on the farm.

Return current? Actually... depending on what loads are on what phase at any given moment any of those phases can have an unbalaced return current on it. Line current moving in one direction... unblalanced return heading the other ---on the same wire. That's part of the reason delta is hard to get good regulation on... and it's hard to balance the feeder load current .

[climbsomemore]

Dallas... I cant see the picture clearly... I'd suspect thats a ground switch in the station.

We used to do something similar at FPL... they installed station ground switches on the high line side. You had to close those ground switches (as part of the Switching Order) so you could get your working grounds on the line. On the 500 kV ... they would order the arcing horns gaps closed for the same reason,,, If you missed that... you would burn the line down drawing an arc with the working grounds.( hey... inductive and capacitive current is bad stuff if your line is long enough!(

[MI-Lineman]

but as you know .... 'return on investment' is everything to the mob at Jackson.

You get "ok" regulation with 2 units. You could spread 3 regs out on three poles in a row too... but 3 costs a third more.

Some of the old delta towns I worked around had a "neutral" strung block to block... but it never went back to the substation ground grid. It was just a buss that was grounded to earth. Theory tells us that all current want's to return to the source... and when we create a ground at the transformer pole that's as far as it goes.*ok I lied--it will travel in the earth till it returns to the generator* If you ever get to Sturgis Mi... it was built like that in many blocks... and the neutral was taken to the subs when the conversions took place.

Corner grounding delta secondary... you can place as many "grounds" as you want on one phase of any delta system... get a ground on either of the others... a short circuit will travel through the dirt and blow fuses.

Corner grounded delta secondary is big in the oil patch and on farm irrigation... years ago they found that having a phase bonded would make motor protection fuses more reliable. To further muddle the issue- Consumers Energy calls an accidental secondary ground a "power ground"... took me about 2 years to figure out what the fluck they were talking about.

The old substation boards... there was a light for each phase... if the lamp lit there was a ground on that phase. Byron had some old model T era photos on this website of men and equiment checking for circuit grounds.

MI Lineman...that "split neutral" you guys make for dairy and livestock farms is simply isolation of the "secondary neutral" from the grounds on the primary arrestors and tank grounds. They put a little LA between the two ground schemes to tie them together if they have to carry an over voltage to earth ... that limits a possible flashover between the down grounds. The idea is if you divorce the secondary return current from the y system neutral you can limit any circulating currents from the power line to any bonded metal on the farm.

Return current? Actually... depending on what loads are on what phase at any given moment any of those phases can have an unbalaced return current on it. Line current moving in one direction... unblalanced return heading the other ---on the same wire. That's part of the reason delta is hard to get good regulation on... and it's hard to balance the feeder load current .

OOO.KKK.! I guess you know who to ask now Dallas!!!:D Thanks for takin the heat off me Climbsomore!!!!:D Good to hear from ya again!!!!

[wtdoor67]

Electric Transmission and Distribution
by "Skrotzki, Bernhardt G.A.; Contributors: E.M. Adkins, F.S. Benson, E.L. Michelson "
Publisher: Seller: Harvest Books
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"Hardback. / McGraw-Hill Book Company: 1954; 448p / Condition: Very good condition., No dust jacket. / Stock#: 850310 (290-D) * * WE SHIP NEXT BUSINESS DAY * *"
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-------------------------------------------------------------------------

I found this one on the Barnes and Noble website. There were several. This one was $10.40. Get with it dog.

[Trbl639]

All I have ever been told was put the grounded leg in the middle or it won't meter.

So if it's ungrounded the middle leg they could get some free usable voltage out of it with it being glass covered...never thought about that...I guess depending on the meter can itself...I'd have to look at it more.

That's right...........look at a 5 terminal 3phase can........3 meter lugs on the top/line side...2 on the bottom/load side...we called them HQ-5's.......there is a bar between the middle lug on top and the bottom, got a nut on it..loosen the nut and the bar falls down leaving no connection between the line/load side..........if ya pulled the meter and pie plated it, without opening the bar, the middle lug/phase/load side was still hot, if the bank was still hot...............

We grounded the middle phase, cause guys would pull the meter to t/off one well, leaving the bank hot to feed another well and NOT drop the bar..........narrowbacks would come out to do something, see no meter and get their dicks knocked in the dirt, thinking it was all dead......so we started grounding them to stop that..........

[Trbl639]

Dallas... I cant see the picture clearly... I'd suspect thats a ground switch in the station.

We used to do something similar at FPL... they installed station ground switches on the high line side. You had to close those ground switches (as part of the Switching Order) so you could get your working grounds on the line. On the 500 kV ... they would order the arcing horns gaps closed for the same reason,,, If you missed that... you would burn the line down drawing an arc with the working grounds.( hey... inductive and capacitive current is bad stuff if your line is long enough!(

We had those in the subs on 115 and 161KV, but the Transmission Dispatcher would never tell you to close them when you switched out a line..cause they didn't pull maint. on them and were unreliable, might not make up good or 1 phase might not even make contact or they would fall out about a foot or so.......but I know where you are coming from, makes for a pretty good fire........

[Trbl639]

but as you know .... 'return on investment' is everything to the mob at Jackson.

You get "ok" regulation with 2 units. You could spread 3 regs out on three poles in a row too... but 3 costs a third more.

Some of the old delta towns I worked around had a "neutral" strung block to block... but it never went back to the substation ground grid. It was just a buss that was grounded to earth. Theory tells us that all current want's to return to the source... and when we create a ground at the transformer pole that's as far as it goes.*ok I lied--it will travel in the earth till it returns to the generator* If you ever get to Sturgis Mi... it was built like that in many blocks... and the neutral was taken to the subs when the conversions took place.

Corner grounding delta secondary... you can place as many "grounds" as you want on one phase of any delta system... get a ground on either of the others... a short circuit will travel through the dirt and blow fuses.

Corner grounded delta secondary is big in the oil patch and on farm irrigation... years ago they found that having a phase bonded would make motor protection fuses more reliable. To further muddle the issue- Consumers Energy calls an accidental secondary ground a "power ground"... took me about 2 years to figure out what the fluck they were talking about.

The old substation boards... there was a light for each phase... if the lamp lit there was a ground on that phase. Byron had some old model T era photos on this website of men and equiment checking for circuit grounds.

MI Lineman...that "split neutral" you guys make for dairy and livestock farms is simply isolation of the "secondary neutral" from the grounds on the primary arrestors and tank grounds. They put a little LA between the two ground schemes to tie them together if they have to carry an over voltage to earth ... that limits a possible flashover between the down grounds. The idea is if you divorce the secondary return current from the y system neutral you can limit any circulating currents from the power line to any bonded metal on the farm.

Return current? Actually... depending on what loads are on what phase at any given moment any of those phases can have an unbalaced return current on it. Line current moving in one direction... unblalanced return heading the other ---on the same wire. That's part of the reason delta is hard to get good regulation on... and it's hard to balance the feeder load current .

Heard that too, but it didn't work real well in a lot of places here..........the narrowbacks/farmers/pumpers had most of the heaters in the magnetics 'slugged'!!!! Then It would back up on us and blow a pot fuse, they'd call us and be no where to be found when we got there........we'd check it out, open their main, re-fuse the pot, check voltage, leave a door hanger and go on our merry little way..........used to piss em off!!!

[rcdallas]

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