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# Calculating Reactance and Resistance of Transformer Without Copper Loss Data

06/24/2015 2:43 AM

I have a 10MVA and 36MVA data sheet. It has the percentage impedance volts from which i have calculated impedance. But it doesn't mention the copper loss or X/R ratioand hence i don't know how to calculate the values of X and R. Its an important part of my assignment. Any idea how this can be done?

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#1

### Re: Calculating reactance and resistance of transformer without copper loss data

06/24/2015 3:16 AM

start here: https://en.wikipedia.org/wiki/Copper_loss

Then try this.

The rest is part of YOUR assignment and should be done by you.

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#2

### Re: Calculating Reactance and Resistance of Transformer Without Copper Loss Data

06/24/2015 11:13 AM

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#3

### Re: Calculating Reactance and Resistance of Transformer Without Copper Loss Data

06/24/2015 1:16 PM

In my opinion-I don't know for what purpose you need this-you can take the average shown in ANSI C37.010. See for instance :

Since for this size the ratio X/R >15 the difference between Z and X is negligible-in my opinion.

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#4

### Re: Calculating Reactance and Resistance of Transformer Without Copper Loss Data

06/24/2015 2:20 PM

It's a homework assignment, a real nameplate includes the per unit or per cent impedance and the base quantities that it is based on.

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