Delta and Wye ?

[billg]

Can't always rely on those job cards. (I work on NG property,too.) For example: multiple circuits on the pole; I have yet to see more than one circuit number on the card. Or, beyond step-downs, the circuit number and letter designation don't change. We can never take anything for granted. Name plates on the transformers will verify it.

["little beaver"]

First off delta systems have no reference to ground so all of your voltage is phase to phase.
If you have one ground fault nothing is going to happen (fuse will not open) untill the second fault which would cause your short circuit, unlike a wye system which has a reference to ground & I think that is why deltas are more dangerous than wye ststems

This is the correct definition of a Delta system. There is no Voltage to gorund on a perfectly insulated Delta system.

A Delta connection on the primary side is 'dangerous' if one is acustomed to operating on a Wye system. When you open the first cutout you are still 'hot' to both the top and the bottom of the cutout until you open the
second cutout.

On a 1 ph connection on a Delta system, you would generally have two cutouts on a Xfmer for that reason. In the Oil Patch I've seen just one cutout on a Xfmer with a 'riser' on the other side. OK if you know to pull the cutout open before removing the riser.

Delta connections on the primary side need to be Dual bushing Xfmers.

Case grounds are always used on Delta connections. The case ground has nothing to do with the bank wiring per se.

If you have Delta banks on a system and you lose one ph on the system, it will sometimes circulate through those banks and cause you all kinds of problems, particuliarly on pump jack motors.

[Stick-it]

FYI - I have heard that they do not ground any cases in California.

[johnbellamy]

FYI - I have heard that they do not ground any cases in California.

What is the reason for not grouding the case of any device, pot's, regs, caps, field recloseres, sects, or any device? Safety wise or electrically?

[Stick-it]

What is the reason for not grouding the case of any device, pot's, regs, caps, field recloseres, sects, or any device? Safey wise or electrically?

Sorry, I meant x-fmrs. I couldn't tell you about all the others you listed. The reason? I don't have a clue. Doesn't make sense to me either. They put plastic covers over the nuts and call it good. Seems dangerous. They must use 2 bushing cans exclusively if they are doing that though.

[johnbellamy]

Sorry, I meant x-fmrs. I couldn't tell you about all the others you listed. The reason? I don't have a clue. Doesn't make sense to me either. They put plastic covers over the nuts and call it good. Seems dangerous. They must use 2 bushing cans exclusively if they are doing that though.

If the case ground on a pot is not grounded , would'nt the case be energized at the primary voltage? I have worked mostly wye distribution that has a system neut, I know on a delta you have to have a two bushing pot for phase to phase, but there are alot of single phase single bushing pots, I never used them in a three phase bank, but i have used them in a wye open delta installation.

Maybe some one can help us out on this. Thanks

[johnbellamy]

Well, first off, let me say...
I'm a hippocrate too John. By Choice.

I said I'd never post to you again.

But, tryin to get along, has always been one of my traits.

This ain't "Swamprat.com".

I just Been here man,... since 2002, back when this board was ALOT different than it is now.

You just found this board in 08, and jumped in with both feet. Welcome.

I've had runins with a few guys on this board....and there's guys here that don't like me.
Water off a duck.

Every apprentice I've ever had....cept 1...is now a Union Lineman. Cause that's where I directed em.

Your Union Only thing is all well and good.
But, there's alot of other aspects of Linework, you....just seem to dust over.

Like, Utilities.
That,.. treat their employees fair, keep em happy, and they are perfectly content, being non union.
Does that make Them....Rats?

So, anyway....cut to the chase.

You're a die hard Union Lineman. And I hear all your talk about "Rats" takin your Union Jobs. I also hear guys like Labor...with a "clear resounding voice".

I don't do "books" real well either man, I'm a "picture, draw and show me, and I'll remember." type of guy.

It's worked just fine for me in all my years in Linework.

To me, LINEWORK...is what it's Really all about. And I LOVE it to the core.

So,
can you and I talk civil to each other, or....ya still want to come down to Orlando and try and kick my ass? Or...ya want to just carry on with the Rat, hate shit?

Your call...

I am a black and white guy, I am quick to fight, then ask questions later, thats who I am, I won't bust your balls, but I am frustrated with the way thing are goin.

I understand some non union oufits treat there lineman well, but here in lies the problem with that, I hear from some union paying members, say " Why do we need the Union, can't we just cut our own deal", or I hear non union lineman say "Why should I pay dues like you, the company will take care of me" I am not a "company man"

The Union was started for the well being of lineman, It stands for something, It is a Brotherhood, so I appriciate you directing your apprentices to become Union, I believe you know that It is a better for them.

What I have seen is the explotation of young, hard working, but also untrained non union lineman do work they have no business doing, would not be allowed to do if they worked for a union outfit. These guys are willing and if properly trained, will make good lineman.

Again I know there are alot of young hard working guys that would make good lineman, but are not givin the oppertunity because they cant pass the written tests, or score high enough, they will test 200 but will only give skills to the top 50, This problem needs to be adressed, linework is mostly physical, so I would choose to work with a guy like that, a guy who can build it, rather than one who can tell me phase angles, and such. But that being said you need to have your head cut in to do this work.


There is alot of knowledge out there, so I will keep my comments on rats, and labor issues out of things as long as others do the same, "don't go start nothin, ain't goin be nothin. But I see you come down on guys to, make some pretty bold statments at times, so lets talk linework.

[wtdoor67]

Beats the shit outa me Swamp, just the way we do it, or in my case, did it, never asked. Couldn’t have a ground wire less than an inch& half from the hanger brackets. Never seen any problems or anyone getting shocked because of it. Maybe I’ll run across one of the company scientists & see what they have to say about it.

on a single bushing pot you must connect the case ground because the pot will not work if the case isn't grounded.

On a two bushing pot there is a very slim chance under precise circumstances where the case could become energized. Just a safety issue in most instances.

[lewy]

All of our new txs are single bushing primary with a ground strap on th X2.
H2 is welded to the case along with a seperate case ground connection.
Your H2 & case ground should be seperate connections to the neutral & we do not tie H2 to X2 .
On 2 bushing primary txs we run a tap from H2 to X2 just for backup because if you did not the wire coming out of H2 if broken & your only connection to ground would be at line potential.
That is also why we ground all of our txs with a seperate connection.

[500 KVA]

Grounded Delta. You are correct. Good call! I let the cart get ahead of the horse on that one. I need to think a second before engaging fingers.

From what I've been told, they do not ground any single phase in California. Not certain about reclosers etc... They cover every bolt with plastic to protect climbers from coming in contact with any bolts. I believe they give the customer a ground reference at their meter panel.