How do you calculate full load amps for the primary side of a transformer?

To calculate full load amps for the primary side of a transformer, the formula involves the transformer's kilovolt-amps (KVA) rating, the primary voltage (EP), and the square root of 3 (approximately 1.732), which is used when dealing with three-phase systems.

The correct formula, which is represented in the correct answer, breaks down as follows: when you need to find the primary current (IP), you start with the KVA rating of the transformer. Since power (in kilovolt-amperes) is related to voltage and current by the equation P = VI (where P is power, V is voltage, and I is current), you can rearrange this equation for current as I = P/V.

In three-phase systems, the total power is multiplied by the square root of 3, which accounts for the phase difference. Hence, by using the formula IP = KVA x 1000 / EP x 1.732, you are ensuring that the value for current is correctly calculated by converting KVA to watts (there are 1000 watts in a kilowatt), and dividing that by the line voltage and adapting for the three-phase nature of the system with the square root of