Heat cycle and short circuit test equipment design

Thread Starter

daljeet795

Joined Jul 2, 2018
294
Hello there

I am looking for information of transformer attached below. somebody know what type of transformer is this ? I suspect its Oil Cooled Transformer.
There is HV and low LV bushing. Is LV is output and HV bushing is input of transformer.
 

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SamR

Joined Mar 19, 2019
2,888
If it is an older oil-cooled transformer it may be PCB contaminated and require hazardous waste remediation cleaning by a transformer rebuild shop or hazardous waste disposal. The oil will need to be tested if it was built circa 1979 or earlier.
 
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Reloadron

Joined Jan 15, 2015
5,713
If it is an older oil-cooled transformer it may be PCB contaminated and require hazardous waste remediation cleaning by a transformer rebuild shop or hazardous waste disposal. The oil will need to be tested if it was built circa 1979 or earlier.
Side note: About 35 years ago I was with a company (Lear Siegler Power Equipment Division). We paid to have a large transformer removed and replaced, a PCB transformer. Paid a hell of a fee. About three years later that transformer turns up in an abandoned warehouse here in Cleveland. We got a call about it. The removal company was defunct and out of business. Guess who still owned it? :) Transformer nameplate data and serial number went right to us.

On the pictured transformer look for any name plate data.

Ron
 

Thread Starter

daljeet795

Joined Jul 2, 2018
294
I am the part of a team that wants to develop a test system to verify terminal lug type 630 sq mm and 300 sq ms as per IEC standard. I am only responsible for the hardware design I spoke with a guy who has seen this type of equipment but he doesn't know much because his background is mechanical engineering. I am doing reverse engineering I have created one block diagram as per his dissussion

I am trying to understand the relationship of each block with another block. a motorized variac is powered with 240 V Ac. computer sends a signal to NI board and board send a signal to SSR board that control relay board and the relay will control the motor of variac transformer. the output of variac goes to the input of the oil-cooled transformer. non-insulated U shape copper wire is connected to the output side of the oil-cooled transformer. a current transformer is used to measure the current through copper cable. there is thermocouple connected on the cable to measure temperature on the cable. another end of the thermocouple is connected to a data logger system that would send data to a computer. the output of the current transformer goes to the input of isolator and the output of isolator goes to the input of NI board and output of NI goes to the computer

I am not worried about the specification of each part I am just trying to figure out how all system will work. Am I making the wrong relation with part
 

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MisterBill2

Joined Jan 23, 2018
7,679
If you are hoping to check for a short circuit someplace, having a solid short circuit across a winding is probably not going to provide much information.
The common way to check for shorted turns in a transformer is to apply a DC pulse and observe the waveform of another winding, as the voltage is applied and removed. This can be done with each winding. Then connect a shorted circuit across one winding at a time and repeat the tests.
A shorted turn or turns will dampen the AC waveform that is created as the pulse is applied and removed.
 

Thread Starter

daljeet795

Joined Jul 2, 2018
294
A shorted turn or turns will dampen the AC waveform that is created as the pulse is applied and removed.
I am trying to figure out how the conductor is heated and cooled for testing but when I look at the block diagram, I don't understand exactly what happens
 

MisterBill2

Joined Jan 23, 2018
7,679
OK, I don't see how the transformer is cooled, but the method of heating is clear to me. A current is passed through the conductor, and the power dissipated in the conductor resistance causes heating. That method of heating a transformer is a standard approach.
But nothing in the block diagram shows any method of detecting the temperature of the winding.

So far I am not aware of what information about the transformer is being sought. So a very good starting point is letting us know what it is that the TS is seeking to learn about this transformer. It looks like ma rather large transformer, and so there should be an identification tag providing both the name of the builder company and also a model number.
Certainly the equipment shown in the block diagram is a fairly expensive setup, and so there must be a great need to discover whatever information is being sought. Surely more is required than verifying the terminal connections.
So please let us know what information is being wanted to discover.
 

MaxHeadRoom

Joined Jul 18, 2013
21,958
Looks as though another transformer has been substituted, that wasn't the first photo.?
The original had a oil cooling resevoir tank.
Max.
 

Reloadron

Joined Jan 15, 2015
5,713
Looks as though another transformer has been substituted, that wasn't the first photo.?
The original had a oil cooling resevoir tank.
Max.
It was. The first image was removed and another image inserted. Unless the thread starter can post some accurate true data and images there is no easy way to give accurate help.

Ron
 

MisterBill2

Joined Jan 23, 2018
7,679
The process of heaing a transformer and then measuring the change in winding resistance is close to the same no matter what size the transformer is, oly the numbers are quite different as the types vary. My question is more about what does the TS want to discover with the test setup in the block diagram.

Until that information is known only guesses can be made.
 

DarthVolta

Joined Jan 27, 2015
521
My big 500W isolation transformer sure gets hot. I beleive it's a Hammond trans, and they basically make the same thing to sit in a paino/organ...that's plugged in 24/7. So I guess it's ok
 

Thread Starter

daljeet795

Joined Jul 2, 2018
294
Looks as though another transformer has been substituted, that wasn't the first photo.?
The original had a oil cooling resevoir tank.
Max.
This is original

1604750554145.png

variac input 240 ac and output 270 ac

My question is more about what does the TS want to discover with the test setup in the block diagram.
I wants to develop a test system to verify terminal lug as per IEC standard I am doing reverse engineering. I have discussed with guy who was involve in this type of project in previous company but he knows only little bit because he was only responsible for mechanical work . I have created one block diagram as per his discussion and reading many documents. I thought it would nice plan to start with block diagram
 

MisterBill2

Joined Jan 23, 2018
7,679
I am confused about the meaning of " to verify terminal lug as per IEC standard " . What is there to verify about a terminal lug?? An evaluation of the weld integrity could be done with an X-Ray inspection, or by running the transformer at rated current and using an IR viewer to see the temperature. So I am still not understanding why that requires such a test system as the one in the diagram.

The one in the picture is a lot bigger, at least 100KW, probably more. A different ball game.
And a caution is that some of those transformers use aluminum wire with a copper tinted varnish. Cheaper and lighter but much less durable. And not accepted for production equipment by Ford.
 
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Thread Starter

daljeet795

Joined Jul 2, 2018
294
The one in the picture is a lot bigger, at least 100KW, probably more. A different ball game.
And a caution is that some of those transformers use aluminum wire with a copper tinted varnish. Cheaper and lighter but much less durable. And not accepted for production equipment by Ford.
I have this image for transformer unit but I am not sure if this is regarding for mention transformer

1604751816547.png
 

MisterBill2

Joined Jan 23, 2018
7,679
Amazing! the one in the picture must be much smaller than it looks. and 5 volts and 1000 amps is 5KW, and so I am guessing that such a transformer may be a heater supply transformer for a very high powered tube circuit of some kind.
 

Thread Starter

daljeet795

Joined Jul 2, 2018
294
I am confused about the meaning of " to verify terminal lug as per IEC standard " . What is there to verify about a terminal lug??
We have client requirement to test their lug connectors for power cables as per IEC standard. I am just researching on the subject
 

MisterBill2

Joined Jan 23, 2018
7,679
OK, for testing the actual lugs and connection I suggest also being able to measure the voltage across the connection, between the lug on the wire and the lug on the transformer, .and also using an infrared camera of some kind to observe the temperature. That will allow you to provide a very impressive report.
 

MisterBill2

Joined Jan 23, 2018
7,679
I am aware that the design ot a transformer such as these is certainly very involved and covers a wide range of things. I am also aware that many design or construction flaws show up as a temperature rise and a voltage drop. Certainly there are certain ways of testing already created that will provide quantitative data. Hopefully the TS has already studied those texts and standards, which often describe the test process in minute details. That is not what I was doing, OK?
 
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