Closed Delta Transformer Size Calculator

Formula

The formula to calculate the transformer size is:

\[ S = \frac{I \times V \times \sqrt{3}}{1000} \]

Where:

\(S\) is the transformer size in kVA
\(I\) is the load current in amperes (A)
\(V\) is the line-to-line voltage in volts (V)
\(\sqrt{3}\) is the square root of 3 (approximately 1.732)

What is a Closed Delta Transformer?

A closed delta transformer is a type of three-phase transformer connection where the windings are connected in a closed loop or delta configuration. This type of transformer is commonly used in power distribution systems to provide three-phase power. The closed delta configuration allows for the transformer to continue operating even if one of the phases is lost, providing greater reliability and redundancy. Additionally, closed delta transformers can handle higher loads and provide better voltage regulation compared to other transformer configurations.

Example Calculation 1

Let's assume the following values:

Load Current (I) = 50 A
Line-to-Line Voltage (V) = 400 V

Using the formula:

\[ S = \frac{50 \times 400 \times \sqrt{3}}{1000} = \frac{50 \times 400 \times 1.732}{1000} = 34.64 \]

The Transformer Size is approximately 34.64 kVA.

Example Calculation 2

Let's assume the following values:

Load Current (I) = 75 A
Line-to-Line Voltage (V) = 480 V

Using the formula:

\[ S = \frac{75 \times 480 \times \sqrt{3}}{1000} = \frac{75 \times 480 \times 1.732}{1000} = 62.35 \]

The Transformer Size is approximately 62.35 kVA.