Transformer Rating
Transformer Rating
(OP)
Given a Transformer without nameplate, how do I find the find the Rating of the transformer at site where there is 415V?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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RE: Transformer Rating
Is it in service or sitting idle?
Where did you find it?.
What do you know about its history?
Photos?
Size and type of transformer? dry/oil filled?
Physical condition?
Voltage ratio? Meggar readings?
Type and size of windings conductors?
If you have most of the above info, there may be a remote chance of estimating something.
Rafiq Bulsara
http://www.srengineersct.com
RE: Transformer Rating
"If you have most of the above info, there may be a remote chance of estimating something."
Muthu
www.edison.co.in
RE: Transformer Rating
When the current starts to increase disproportionately to the voltage increase, you have reached magnetic saturation. The next lower reasonable standard voltage is probably the rated voltage.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Transformer Rating
Grin!!
Nothing is impossible, just takes longer and costs more money!
Rafiq Bulsara
http://www.srengineersct.com
RE: Transformer Rating
But the volage I have at site is 415V. If I apply 415V the short circuit current obtain is small. How can I obtain the percent impedance with 415V?
RE: Transformer Rating
You can't use that transformer at 415 V so why do you need %Z at 415V?. %Z is only useful at rated voltage ranges.
What are you trying to test or achieve?
Rafiq Bulsara
http://www.srengineersct.com
RE: Transformer Rating
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Transformer Rating
If you require the transformer to be in working condition than others here will have more useful suggestions.
RE: Transformer Rating
RE: Transformer Rating
RE: Transformer Rating
Amps = kVA/kV/sqrt(3)
You could assume a percent impedance and do a short circuit test per your previous post and Bill's post on ratios. Then you can calculate the kVA that will give you the assumed impedance.
The problem is, for a 132-33 kV transformer, impedances range from 8.5% to 13% (this is from an old Westinghouse T&D Manual and may not be current). This method can only get you into a range of kVA ratings.