2MVA Transformer Core replacement

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Elec-Eng

Member
Location
Niagara Falls
Hello All,

Item#1 on the list has selectable secondary tabs for 600V and 550V. Can the transformer core item #2 be swapped with item #1? Do you see any issues and concerns with this?
I would appreciate any comments or suggestions.

Manufacturer
Rated KVA
Primary
Secondary
Temp. Class
BIL
%IZ
Phase
Weight

#1
Polygon Transformer
2000/2667
13800
600/347, 550/318
220/80
95KV
5.5
3
11300 LBS
#2
Polygon Transformer
2000/2667
13800
600/347,
220/80
95KV
6.1
3
13000 LBS
 

templdl

Senior Member
Location
Wisconsin
Hello All,

Item#1 on the list has selectable secondary tabs for 600V and 550V. Can the transformer core item #2 be swapped with item #1? Do you see any issues and concerns with this?
I would appreciate any comments or suggestions.

Manufacturer
Rated KVA
Primary
Secondary
Temp. Class
BIL
%IZ
Phase
Weight

#1
Polygon Transformer
2000/2667
13800
600/347, 550/318
220/80
95KV
5.5
3
11300 LBS
#2
Polygon Transformer
2000/2667
13800
600/347,
220/80
95KV
6.1
3
13000 LBS
Are you doing this yourself? Did you consult with an engineering service company who would be more qualified with this type of work?
 

Phil Corso

Senior Member
Templdl...

Your description notes only similar electrical features! I presume physical differences (#2 is about 1/2 ton heavier) are acceptable!

But you haven't mentioned other facts regarding its electrical condition. If you have performed electrical tests and all are OK, then I have just one major concern. Have you determined the core is intentionally bond-able to the support structure at an identifiable point?

Regards, Phil Corso

PS: Would you like to hear a Murphy-Law story involving replacement of a core into its tank?
 

Tony S

Senior Member
Why do you need to exchange the existing core? What cooling do they use? If they are oil cooled can you do the vacuum drying that will be needed on re-tanking the cores? What have Polygon Transformers had to say about your proposal?

Our company did a core replacement once on one of our 2.6 MVA single phase dry, air cooled transformers. I’ll be honest it was one of those jobs we wished we had never started even though the new core has made by the original manufacturer.

How did this job go? http://forums.mikeholt.com/showthread.php?t=172932&highlight
 

templdl

Senior Member
Location
Wisconsin
Templdl...

Your description notes only similar electrical features! I presume physical differences (#2 is about 1/2 ton heavier) are acceptable!

But you haven't mentioned other facts regarding its electrical condition. If you have performed electrical tests and all are OK, then I have just one major concern. Have you determined the core is intentionally bond-able to the support structure at an identifiable point?

Regards, Phil Corso

PS: Would you like to hear a Murphy-Law story involving replacement of a core into its tank?
FYI, I was asking the OP the question. It appears as though those who are the actual experts are bring avoided. FRTOM the specs as included in the OP I would understand that thing is a dry type transformer question. Without kno we ING the size of the enclosure as ns the size on mounting dimentions and clearances of the core and coil proposed as a replacement it is a wild guess if it would be doable. This is why it would be best to request input frtom custom transformer for a proposal regarding their ability to manufacture a core and could assembly that should mount in the existing space.
My guess that you would be able to given the information as provided. It would be worth the time to replace an appropriate inquiry with a custom transformer providing them with a drawing of the existing transformer.
 
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