Home › Electrical Engineering Forum › General Discussion › Will there be any change in capacity rating of a 3 phase 750 KW generator if to change from 440 VAC to 230 VAC? › Re: Will there be any change in capacity rating of a 3 phase 750 KW generator if to change from 440 VAC to 230 VAC?

@guest said:

Will there be any change in capacity rating of a 3 phase 750 KW generator if to change from 440 VAC to 230 VAC?

Dear ;

First, the Power’s unit of any source ” Transformer, Generator, … ” is given in * ” Apparent power – S ” *and the unit is

**” kVA “**

Even that your question is not too clear, I will try to clarify that point as follow :

Assume that we have 2 sources with the same rating power of each one ” 200 kVA “, but the output voltage is different where that’s ” 400V – 3 phase ” for the 1st and ” 230V – 3 phases ” for the 2nd, and as the Power is the * multiplication of the Voltage value by the current value*, and the Power for both are the same, in this case the

*will be different that can be calculated as following :*

**”****Nominal Current – I**n**“****S = 1.732 **x** U**o x** I**n**→** **I**n** = S / 1.732 **x** U**o

so, the Nominal Currents are :

for the 1st source :

**I**n(1) = 200 x 1000 / 1.732 x 400 ≈ **289** A

for the 2nd source :

**I**n(2) = 200 x 1000 / 1.732 x 230 ≈ **502** A