What would happen?

[lineman2010]

I just took my JL test in Mountain States a couple weeks ago and for my pole yard task I had to take a closed wye/delta bank and make it an open wye/delta bank. The pot I had to take off line was the lighter pot. I made the open by making one of the power pots the new lighter pot by changing the H1 feed to that of the original lighter pot, and then dropping out the phases on that power pot and then moved over the Xphases to the same location on the new lighter pot.

Now, what I thought about doing for a second was just grounding the X2 bushing on both of the power pots and just dropping out the orginal lighter pot. I was not sure what would happen though since with a Delta the wild leg is always 3 coils out from the ground. Since I would have grounded 2 X2 bushings I was guessing I would have fluctuating secondary voltages since each X2 ground would place the wild leg at a different place. So I figured I might as well ask you guys and see what you guys say would have happened.

[lewy]

You can only ground 1 transformer X2 on a delta, the second 1 would cause a short.

[rcdallas]

Yes sir...you can only ground one time, whether it be a single tub or a bank of em.

If you end up reversing the polarity, instead of the x1 to x3 by going x3 to x3 you'll end up with some screwy voltage like 340 volts.

[Trbl639]

Yes sir...you can only ground one time, whether it be a single tub or a bank of em.

If you end up reversing the polarity, instead of the x1 to x3 by going x3 to x3 you'll end up with some screwy voltage like 340 volts.

X2.........

[rcdallas]

X2 ?

You saying you'd get a freaky voltage if you tie x2 in?

Where I've seen it specifically was on a open wye-delta bank, where the x1 went to x1 and x3 went to x3, if I remember right when checking the power leg that's where it was around 340 volts or so.

The case I had seen it we were called to change out a power pot. We labeled everything the way that it was, hooked it back up the same way, both pots were the same polarity and when checking voltage before giving it to the customer we seen after checking the power leg it was around 340 volts.

The bank fed some residential customers for their A/C, I think only one had a 3 phase service.

It turned out the bank was originally installed years ago wrong, nobody checked voltage. I honestly don't know how it took that long for someone to call in.

I bet the power pot was never bad.

[Trbl639]

]X2 ?
[/B]
You saying you'd get a freaky voltage if you tie x2 in?

Where I've seen it specifically was on a open wye-delta bank, where the x1 went to x1 and x3 went to x3, if I remember right when checking the power leg that's where it was around 340 volts or so.

The case I had seen it we were called to change out a power pot. We labeled everything the way that it was, hooked it back up the same way, both pots were the same polarity and when checking voltage before giving it to the customer we seen after checking the power leg it was around 340 volts.

The bank fed some residential customers for their A/C, I think only one had a 3 phase service.

It turned out the bank was originally installed years ago wrong, nobody checked voltage. I honestly don't know how it took that long for someone to call in.

I bet the power pot was never bad.

Sorry bout that dallas.....

I meant times 2 (X2) that I agreed with the above post......Not X2 as in a bushing...on another site, a lot of times we quote another post and add X2

[lineman2010]

Cool thanks guys, I was pretty sure I would not be able to do it that way, but was not sure why.

[rcdallas]

Sorry bout that dallas.....

I meant times 2 (X2) that I agreed with the above post......Not X2 as in a bushing...on another site, a lot of times we quote another post and add X2

Gotcha...boy you had me banging my head just about