Mr Delta Door and others alike...

[rcdallas]

Ok after going back up to Michigan again I looked at the delta system I had in question. I came up with a cheesy diagram that shows a lot of what I saw.

Basically they'll run a neutral for say 5 spans or so and it deadends, I assume it's just to provide some redundancy with the imbalance of the transformer and provide a better ground over all.

Tell me what you think. :cool:

[electric squirrel]

You've graduated from crayons,,,,,,,nice!

[topgroove]

Looks like a complete waste of 1/o acsr to me. the only possible bennifit it could provide would be to help dissapate a lightning strike, provided the arrestors were hooked to it and nothing else. are there down grounds attached to the conductor at the other poles?

[bones]

Cool..........!!!

(creepy xfile music)

This is like line-xfiles. No one believed me when I to saw a dry transformer but I did see it, I did!


That being said, I cannot believe drawing without picture:o

[Pootnaigle]

Ummmmmm maybe could be a secondary neutral, But if it aint i dunno what purpose it would serve. I'm kinda agreein with Grovester on this un.

[Trbl639]

We had a lot of this in the Delta region of NE Arkansas.......lots of irrigation wells and few residential customers, except it was wye, not delta......just had miles and miles of no neutral, and almost all of the banks were Delta/open delta, unless there was a span or two of neutral.....usually near a residential customer, and usually had a 2 bushing pot, connected Delta (14.4 pot).......if it went bad and there was some neutral for for a few spans, we replaced it with a conventional single bushing 7620 pot.......never knew why it was like that, just the way it was......

[Highplains Drifter]

And being as you "came up with" this Cheezy drawing...of what ya saw...it would be real interesting to hear from a Lineman that actually works with that type of Delta System.




Look who just brought up Cheese....I think rcdallas's drawing is self explanatory...or did you need a little cheese on the pole tops?

[rcdallas]

That's what I believe I had saw, things like that. I'm certain there was pole grounds attached to the make shift neutral, but I'm not 100%.

Some spans would have open wire, others just ran the make shift neutral like that.

After stopping at the nuclear plant and taking pictures of the company sign with IBEW local 17 on it and having all kinds of people looking at me doing what I was doing, I thought it'd be best I didn't start stopping everywhere and taking pictures left and right drawing more attention to myself. Hell I was on vacation, I just wanted to get away and drink myself silly.

Now MAYBE, ya'll might understand as to where I was coming from when I had and still have hundreds of questions on a delta system!!

From what I've been told so far, out that way, one day you do this and the next day you do that. Not a whole lot of consistency.

It'd be real nice if a lineman who works for DTE would care to chime in on this.

[Highplains Drifter]

I have to agree with Trbl639, I have worked lot's of wyes with out a neutral and they get called Deltas..

[rcdallas]

I have to agree with Trbl639, I have worked lot's of wyes with out a neutral and they get called Deltas..

Do what? A wye without a neutral? Educate me.

[rcdallas]

Fu$k you Drifter.

The "drawing" connected 2 phases to the primary. Delta. There weren't Shit connected to the....what EVER the fu$k that shit was dallas was describin.

It could be Ungrounded Wye...Who the fu$k knows? Talkin on a board...is...."Talkin on a board".:rolleyes:

I personally like some Lumbrusco Wine...with my "Cheese".

Easy. It was a simple drawing, nothing elegant. I didn't draw cutouts or lighting arrestors for simplicity. I'm not a mspaint geek. I spent 4 minutes or less on it.

[wtdoor67]

There's plenty of true delta systems with open wire secondary containing a neutral. Never really thought about how it worked but it's common. The neutral is there for return imbalance.

The wye without a neutral is very common also. If you trace the line to the sub. you find that the hookup is wye, but the wire connected to the wye inside the sub. doesn't exist. Sometimes it does but isn't used, maybe. In some instances it's hard to understand if the line is a wye or a delta. Even going up and looking at the transformer labels isn't guaranteed. We've talked of this before. Common in irrigation areas, oil field, anywhere there is a lot of mostly commercial 3 phase. I've worked on it on 4 KV, 12 KV, 20 KV, and 34.5. To get single phase pots to work for single phase you have to have a phase to phase rated pot and hook it delta. As long as the approximate amount of windings are available it'll work just fine.

Consider if you have to build 2 or 3 miles of line to serve just 3 phase installations. Just a hassle to add the 4th wire. Just use 3 wires and wire the banks delta/delta or delta/wye. If a little single phase crops up then just use the phase to phase pots. Did see one are where the residential customers bitched so much about backfeed giving them dim lights that the co. went ahead and added the neutral and eliminated the delta hi side banks.

The only exception in the banks is a 3 pot wye/delta bank. With the hi side floated then you can use the regularly rated pot. I've seen the same secondary voltage from 2 different banks on the same line a few spans apart with one bank hooked delta/delta with phase to phase rated pots and the other bank hooked wye/delta with the lower rated pots.

I had a foreman once tell me one that a certain section of line was delta. It wasn't and I never told him different. It was wye but just didn't have a neutral in that area. He never figured it out.
He used to haul pots out and look at the labels and say. These won't work. I would just say. Yeah they will and go ahead and hang them. Sometimes he would have to be told they wouldn't work. He never did understand it.

[electric squirrel]

Mr. Door....we have that same situation out in Cali with PG&E. They call it a delta system but once it was explained to me by an older lineman as an "ungrounded" wye.

[Pootnaigle]

Ummmmmmm In the refineries all the station transformers have a huge Ground resistor tween the low side ground bushing and the earth ground. The systems are wye but for a neutral conductor they typcally use a stainless steel conductor( which we all know aint a very good current carrying conductor).The phase conductors are all usually copper . In any case they work just fine for both wye and delta hookups. In the event of a major ground fault on the primary feeder the station transformer doesnt see the fault , It merely sees more load on one phase.Supposedly the distribution breaker senses a fault and trips but that aint always the case. Now if they incurr a phase to phase fault I bleve the fault current would pass thru the station transformer.I bleve tween the stainless steel neutral and the resistor the fault current is seriously limited getting back to the transformer. Usual transmission voltage is 69....... distribution voltages range from 2300 delta to 13.8 Kv wye.

[wtdoor67]

I've heard used was uniground in addition to ungrounded wye.

[MI-Lineman]

That's what I believe I had saw, things like that. I'm certain there was pole grounds attached to the make shift neutral, but I'm not 100%.

Some spans would have open wire, others just ran the make shift neutral like that.

After stopping at the nuclear plant and taking pictures of the company sign with IBEW local 17 on it and having all kinds of people looking at me doing what I was doing, I thought it'd be best I didn't start stopping everywhere and taking pictures left and right drawing more attention to myself. Hell I was on vacation, I just wanted to get away and drink myself silly.

Now MAYBE, ya'll might understand as to where I was coming from when I had and still have hundreds of questions on a delta system!!

From what I've been told so far, out that way, one day you do this and the next day you do that. Not a whole lot of consistency.

It'd be real nice if a lineman who works for DTE would care to chime in on this.

You're right RC it would be nice! I've tried before but there doesn't seem to be any on here? Real shame cause there's some good ones down there!

Anyways I'm tryin to understand what you saw....a can hooked Delta with or without a service or any secondary? Or was it just the neutral? If so that's a new one since I've been there! Normally they had a secondary neutral for service and it was bonded to any down grounds. Like I said before after I left they started separating the arrestor grounds from the sec grounds due to voltage problems.

BTW I'm still workin on what ya needed!;)

[lewy]

All of our distribution is wye & we run a neutral for everything, but I was in Alberta this summer & in all of there rural they only run a neutral for a span or 2 when there is a transformer involved, single or 3 phase. Miles of line with no neutral & it is a wye system.

[Trbl639]

All of our distribution is wye & we run a neutral for everything, but I was in Alberta this summer & in all of there rural they only run a neutral for a span or 2 when there is a transformer involved, single or 3 phase. Miles of line with no neutral & it is a wye system.

All of our single phase had a neutral.....unless it had been stolen:D Most of the 2 of 3 phase and 3 phase might have a neutral for a span or two, then none, until ya got to a transformer or a bank.......

[topgroove]

I think there may be confusion over Delta distribution and ungrounded wye. In a ungrounded wye single transformers need a phase to phase primary connection very similar to a delta hookup. On a bank the tubs can will each have a phase connection with the H2's connected and floated.
thats why you will allways see two conducters on a ungrounded single phase wye primary. there are advantages and disadvantages with ungrounded wye systems. For certain industrial manufacturing applications, an ungrounded wye may be the best choice. some manufacturing processes simply cannot take an outage. things like paper mills and glass factories are a couple. Places where an outage would cause a huge mess and days of cleanup.
On a ungrounded wye if a fault occures on one phase there is no return path back to the station breaker for it to open. depending on where the fault occures most of the customers will not be affected. the disadvantages are it is important that the secondary's are as balanced as possible to prevent vector distortion. Thats why you'll see a nuetral wire strung for five or six spans to help even out the imbalance from customer loads. Lightning can be a real problem, thats why you see lightning arrestors every three or four poles or so. on a delta or ungrounded wye lightning protection should always have a seperate ground system with groundrods eight feet apart minimum, I like to use adjacent poles to seperate the grounds even farther.
I'm sure most stations and meter and test people would prefer a grounded wye system, the relay"s at the station are much simpler and straight foward. Working at the same utility for 22 years puts me at a disadvantage because I only have to deal with a 4800 delta, a 4160 wye and 13.2kv wye grounded systems. In one part of syracuse I've seen a 4160 ungrounded wye and it had us scratching our heads on a storm once. Lineman who tramp and contractor lineman are exposed to a hell of alot more systems! with the mergers of utilities and the combining of work practices It would be a good idea for everyone to bone up a little on delta, ungrounded wye and grounded or unigrounded systems.

[Trbl639]

Good explanation Top............

My situation exactly, working at a utility for over 28 of my 38 years....not that much exposure to different systems.the only True Delta I worked was in Remote Alaska, and it was generated there on the site.............the rest was Grounded Wye and Ungrounded Wye.......we almost always connected pots Delta (phase to phase) on the ungrounded wye, I can remember maybe once or twice where we used 2 bushing pots and floated the highside h2 for irrigation wells/relift pumps..........occasionaly we might have to add a span or two of neutral to build a wye/wye bank (277/480) for a grainbin installation.........but we used single bushing pots, cause that's what the engineers called for.....

[Edge]

I think there may be confusion over Delta distribution and ungrounded wye. In a ungrounded wye single transformers need a phase to phase primary connection very similar to a delta hookup. On a bank the tubs can will each have a phase connection with the H2's connected and floated.
thats why you will allways see two conducters on a ungrounded single phase wye primary. there are advantages and disadvantages with ungrounded wye systems. For certain industrial manufacturing applications, an ungrounded wye may be the best choice. some manufacturing processes simply cannot take an outage. things like paper mills and glass factories are a couple. Places where an outage would cause a huge mess and days of cleanup.


not always the case Groove.... read what Lewy had to say then maybe read up on Single wire earth return.

some of the places I worked up in the great white north just shot three ground ronds in the dirt and tied them togeather.... if there was a few spans of "neutral" that was only cuz they drove some rods at those sticks and tied them togeather over head.... most 3 phase was shot to a ground grid at the bottom of the stick of a grounding cage... thats it no "neutral".... just Earth return.... ' door and I've beat this to death a few different times always makes for good discussion...

for what it's worth...

Edge

[MI-Lineman]

not always the case Groove.... read what Lewy had to say then maybe read up on Single wire earth return.

some of the places I worked up in the great white north just shot three ground ronds in the dirt and tied them togeather.... if there was a few spans of "neutral" that was only cuz they drove some rods at those sticks and tied them togeather over head.... most 3 phase was shot to a ground grid at the bottom of the stick of a grounding cage... thats it no "neutral".... just Earth return.... ' door and I've beat this to death a few different times always makes for good discussion...

for what it's worth...

Edge

I understand what you all are sayin but unless they changed somethin that wasn't done in D town? I don't get what RC saw? Was there anything else like secondary to that can?? Course they do a lot of research (or use to anyway) and development down there! Maybe they were tryin somethin like that?

[rcdallas]

[/SIZE]

BTW I'm still workin on what ya needed!;)

Everyday I keep checking...getting all excited, then POOF! :D

[rcdallas]

I always thought, until now anything without a neutral was a delta. This makes sense now that I think about it.

In our oilfield here we feed them primary, install primary metering equipment, and a lot of it they don't run a neutral, it's really an ungrounded wye out here in the oilfield.

I understand all the delta connections on the high side of the transformer, it just seems to me though if it's an ungrounded wye or even a delta there is really no difference if you were to run a neutral for a couple of spans or so on some open wire secondary, just a better reference to ground for the transformer, service neutral, etc...

Really what's the big difference between an ungrounded wye and a delta?

Just the way the relays and stuff are set at the substation for detecting faults? Or let's say on the regulators I posted a few months back, 2 regulators on the outside phases, both connected to the center primary, would that still be the same on a delta AND an ungrounded wye?

I've asked senior cats around here about an ungrounded wye and I get funny looks. New shit day after day...

[Trbl639]

RC.........

Not sure about your question about the regulators......as far as the ungrounded wye and relay settings...........where I worked, we never ran ungrounded wye straight from the sub..it was always tapped off the mainline, behind either single phase cluster kyles or an OCR or fuse switches.......