transformer damage?

[drbond24]

How inconsiderate on your part :grin:

If it were up to me, I'd have turned the power off. I'm just worried about the transformer, but management is worried about that stupid money stuff. :grin: I asked if I could 'accidentally' trip the main breaker, but I got a negative response. :wink:

 

[quogueelectric]

If it were up to me, I'd have turned the power off. I'm just worried about the transformer, but management is worried about that stupid money stuff. :grin: I asked if I could 'accidentally' trip the main breaker, but I got a negative response. :wink:

Ask Elias Anchundia if you should shut the power off. Oh I forgot he cant answer you anymore

 

[mayanees]

xfmr size..

xfmr size..

2.5MVA is pretty small in the scheme of things. Try qty 6 @ 1000 MVA each.

Man I was all set to chime in on having been Project Engineer on a dual 334MVA, 230;69kV substation, but not after qty 6 @ 1000 MVA.
Can I one-up you by describing their 69kV tapchangers??
JM

 

[zog]

We could pull a sample ourselves and send it out, but the POCO here offers that service so we're having them do it. They were chosen as the vendor for this particular test (not by me, I might add).

Ha! The POCO is sampling your transformer to determine if any damage occured, which to me sounds like was thier fault???? I betcha that sample reportt come back looking just fine..

The drain valve is located such that you practially have to crawl inside the secondary compartment to get to it, and the fact that we have 7 parallel runs of 600 MCM cable connected to the secondary makes it less than roomy. It would be dangerous to attempt to manuveur through it with the power on.

This task was just discussed by myself and a couple of 70E commitee members yesterday, this should be done denergized per 70E requirements unless it is life safety related, Etc. If you take any sample from a pad mount energized you definitly need an energized electrical work permit, my company does these all the time, they are routine to us, we have determined to do them energized in some cases, but with an EEWP.

A good solution is to relocate your sample valve to the outside of the door, there are several affordable aftermarket products for that exact purpose out there, we have installed many.

 

[zog]

2.5MVA is pretty small in the scheme of things. Try qty 6 @ 1000 MVA each.

Wow, I have been in the transformer industry for 20 years and have never seen one that big, I commisioned a 500MVA a few years back, it took 19 tanker trucks of oil to fill over 7 days and was the size of a 4 story building, but dang, 6 - 1000MVA units??

Please post pictures!!! I cant think of where these would exist in North America, I used to work at a place that was capable of up to 750 MVA but I dont think we ever had one that big buillt there, I think that was (is, new company now) the largest in the US.

You sure about that? 1000MVA, you didnt mean 100MVA? ABB just installed the largest in Africa recently and it was 400MVA, biggest ever in that country and you have 6 units 2.5 times as big as that??

 

[mivey]

Ha! The POCO is sampling your transformer to determine if any damage occured, which to me sounds like was thier fault???? I betcha that sample reportt come back looking just fine...

IMO, the POCO has deep pockets and insurance to cover any liability issues. They have no reason to falsify a report and know they would just be opening themselves up to liability if they did.

Of course, the utilities I deal with are usually up-front. I'm sure there are some shady POCOs out there as well. I just don't see what they would gain by falsifying a report. I learned a long time ago that the best way is to work on the premise that there is no such thing as a secret.

[edit: while the POCOs can be up-front, they can be up-front with some pretty bone-headed ideas at times]

 

[dbuckley]

In the world of HVDC there are some fairly generously proportioned transformers, but ABB reckon their 621MVA unit is the biggest ever, which is some way short of 1GVA...

 

[zog]

In the world of HVDC there are some fairly generously proportioned transformers, but ABB reckon their 621MVA unit is the biggest ever, which is some way short of 1GVA...

Just going off of rough pricing, I estimate a 1000MVA transformer to cost somewhere around $10M-$15M each if even possible to build, so 6 units may be near $100M in assets, thats amazing, please post these pics!

 

[drbond24]

Ha! The POCO is sampling your transformer to determine if any damage occured, which to me sounds like was thier fault???? I betcha that sample reportt come back looking just fine..

Actually, they are just pulling the oil sample. They're going to send it to a lab for analysis. (http://www.weidmann-acti.com/) I know, we could just pull the oil ourselves and send it to the lab without involving the POCO, but we aren't. :smile:

 

[zog]

Actually, they are just pulling the oil sample. They're going to send it to a lab for analysis. (http://www.weidmann-acti.com/) I know, we could just pull the oil ourselves and send it to the lab without involving the POCO, but we aren't. :smile:

Weidman is a good lab, I use them myself, just make sure they pull a DGA sample, a standard sample and analysis wont tell you much.

 

[zog]

IMO, the POCO has deep pockets and insurance to cover any liability issues. They have no reason to falsify a report and know they would just be opening themselves up to liability if they did.

Of course, the utilities I deal with are usually up-front. I'm sure there are some shady POCOs out there as well. I just don't see what they would gain by falsifying a report. I learned a long time ago that the best way is to work on the premise that there is no such thing as a secret.

[edit: while the POCOs can be up-front, they can be up-front with some pretty bone-headed ideas at times]

I was not impying they would falsify a report, but rather only run the tests that would not tell the whole story or something, oil analysis is not a go-no-go, there are different tests that can be run, different specs to adhere to, different ways of imterpreting the results, you could if you wanted to make a report seem better or worse than it actually is without falsifing anything.

 

[mivey]

Zog, I see what you mean. Thanks for the clarification.

 

[drbond24]

Well, the POCO returned Saturday morning and took a significantly larger quanity of oil than last time. They were going to ship it via UPS or FED-EX immediately after leaving here, so hopefully we'll have some results early this week. I'll continue logging the drama here when there is more to report.

 

[zog]

Are they taking a DGA sample?

 

[drbond24]

Are they taking a DGA sample?

They are going to do several tests and DGA is among them. Also on the list are Furanic Compounds (Insulation Degredation), Fault Metals, moisture content, and dielectric breakdown. There may have been others; we pretty much told them to test everything they possibly could with the oil.

 

[zog]

Very good, post the results when you get them

 

[kingpb]

Wow, I have been in the transformer industry for 20 years and have never seen one that big, I commisioned a 500MVA a few years back, it took 19 tanker trucks of oil to fill over 7 days and was the size of a 4 story building, but dang, 6 - 1000MVA units??

Please post pictures!!! I cant think of where these would exist in North America, I used to work at a place that was capable of up to 750 MVA but I dont think we ever had one that big buillt there, I think that was (is, new company now) the largest in the US.

You sure about that? 1000MVA, you didnt mean 100MVA? ABB just installed the largest in Africa recently and it was 400MVA, biggest ever in that country and you have 6 units 2.5 times as big as that??

1000 MVA they are.... They will be installed at a 6-unit mine mouth site in South Africa. Actually, I was wrong, there will be 7, since they want to have a spare. These would definitely be considered a long..................lead item.

The only country's with hook capactiy for these beasts are in Europe, and I believe Korea.

 

[zog]

1000 MVA they are.... They will be installed at a 6-unit mine mouth site in South Africa. Actually, I was wrong, there will be 7, since they want to have a spare. These would definitely be considered a long..................lead item.

The only country's with hook capactiy for these beasts are in Europe, and I believe Korea.

Let me guess, $100M for the 7 units?

Who is making these for you, ABB?

 

[noonan]

Guess there's some money to be made in mining.

 

[RHJohnson]

I remember standing in awe, staring up at these huge transformers - they too must have been 4 stories. There were 4 (they even had a spare). The cost had to be out of this world. To move them, set them in place - I don't know how they got there, but they sure weren't loaded on any semi!!!