The transformer physical size and output rating

[cirtcele]

I have one application where I may have to replace existing 3750/4687 kVA, 13.2/4.16 kV, 55/65 deg C rise, ONAN/ONAF transformers with 5000/6250 kVA ones.

The problem is space. The existing transformers are using above ground bus duct. Basically, I am restricted with the existing length of the transformer. I have only 1 meter space on one end with the 13.2 SWGR and 0.5 meter one of the other end with 5 kV SWGR. I cannot use the 1 m space since the switchgear located on this side is accessible from back.

The transformer can be made bigger though on both sides where the radiators are currently located.

Now, my question is this doable? What would I lose if I had to opt for this solution, efficiency or extra cost? Is it worthwhile to explore this option?
Any comment?

Thank you...

 

[ScottyUK]

Have you considered larger radiator banks and forced oil cooling? The increase in capacity you are seeking is just about achievable with a forced oil / forced air cooling system, depending on the internal design of the transformer.

Have you considered the likely increase in fault level of the larger transformers? Is your switchgear rated for this?


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I don't have an attitude problem. You have a perception problem...

 

[apowerengr]

Often a 3.75 MVA 55C rise transformer can be equipped to provide 5.25 MVA at 65C FA (depending on the defined ambient temperature conditions). If you need special physical transformer designs to fit an existing space ask the suppliers to design given the dimensions you provide. They can be quite creative if they need to be. Your post did not indicate why you need to replace these transformers.......perhaps it does not matter.

 

[cirtcele]

ScottyUK and Apowerengr:

Yhank you for reply. I guess, I have to contact the suppliers as you indicated. I did not want to ask this question if it would not be worth to do so

The transformer is already equipped with ONAF (fan cooling). I will keep you posted this week. Thank you for your time again.