Looking For Oil Filled Transfromer Impedence
Looking For Oil Filled Transfromer Impedence
(OP)
I have an old Oil Filled 150 kVA 3 phase Transformer. I have no Documentation and need a rough idea of what the impedence would be. The namplate is long gone however based on the age of this plant and upgrades done on it I belive it is likely from the 40's or 50's. I would also like a way to solve these type of problems in the future.






RE: Looking For Oil Filled Transfromer Impedence
What are primary and secondary voltages for this transformer?
RE: Looking For Oil Filled Transfromer Impedence
RE: Looking For Oil Filled Transfromer Impedence
For regulation, you should probably assume about 6% and for fault currents assume about 1.5%. If you need better numbers than those you will likely need to test the transformer.
RE: Looking For Oil Filled Transfromer Impedence
1-150kVA: X=3.0% ; R=1.5%
3-50 kVA: X=2.2% ; R=1.3%
Impedance also may be measured by method specified in the standards with the low voltage winding shorcicuited:
Z% = measured voltage/rated voltage
RE: Looking For Oil Filled Transfromer Impedence
RE: Looking For Oil Filled Transfromer Impedence
typical load center transformer impedances (primary 15kV or less) for 150kVA liquid filled trsfs as 4%
typical distribution transformer impedances (primary 15kV or less) for 150kVA liquid filled trsfs as 3.7%
This data is based on average data for transformers made in the late 1960's
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RE: Looking For Oil Filled Transfromer Impedence
RE: Looking For Oil Filled Transfromer Impedence