Answer / rajesh verma

Dear
Please follow the Step
1 calculate your transformer maximum current with this simple formula
Transformer KVA X 1.39 A = will be the Maximum Tr ansformer Current
2 find out the Cable current Ratings chart from the Cable manufacturer data Sheet accordingly select cable but one thumb rule can help in this matter and it is Per Amp 2 MM SQ will be enough to carry out the current in any circumstances.IE Cable Length ,Cable Joint cable laying condition etc but remember you have to take care the welding load this will not by cover the thumb rule

Answer / h s sandhu

From the Equation P=root 3xVxIxP.F. we can calculate the rated current on the secondary side of the transformer. Knowing the value of rated current  we can select the cable size from the cable selection chart.

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