Delta-Y Transformation: Casio Programming

The delta-y transformation, also sometimes known as "wye-delta transformation" is a mathematical technique used in the field of electrical engineering for calculating loads in three phase electrical systems. Used mainly at an engineering and scientific level, you will not find a general electrician using it.

Although the Casio fx-7000GA is ideally suited to perform these lengthy calculations to save time, I would seriously recommend you do not use a calculator if you are an engineering student. Usually those with a neurone deficit use them for such calculations.

The Wye Network

The Delta Network

Wye-Delta Formula

• R4 = (R1 × R2) / (R1 + R2 + R3)
• R5 = (R2 × R3) / (R1 + R2 + R3)
• R6 = (R3 × R1) / (R1 + R2 + R3)
• R1 = (R4 × R5) + (R5 × R6) + (R6 × R4) / R5
• R2 = (R4 × R5) + (R5 × R6) + (R6 × R4) / R6
• R3 = (R4 × R5) + (R5 × R6) + (R6 × R4) / R4

Program Code

The lines of code shown above are for programming the Casio fx-7000GA, with the transformation. All the symbols are exactly as you would see them on the keyboard of the calculator.

Memory Contents

Program Use

I remember students running out and buying a programmable calculator just to be able to perform the delta-y transformation; it was a huge laugh when they still got the answers wrong!

It was even funnier to see that many could not even program the calculator because programming involves understanding the principles.

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