Which formula is used to calculate the current from the transformer's KVA rating and voltage?

The formula to calculate the current from a transformer's KVA rating and voltage incorporates the relationship between these elements in the context of electrical power. The KVA rating signifies the apparent power of the transformer and is calculated as the product of voltage (in volts) and current (in amperes).

The correct formula, which is KVA multiplied by 1000 and then divided by voltage, is derived from the equation for power:

Power (in watts) = Voltage (in volts) x Current (in amperes).

Since KVA represents Kilovolt-Amperes, it can also be expressed in watts by multiplying the KVA rating by 1000. Therefore, when you calculate current, you need to rearrange the power formula to solve for current:

Current (I) = Power (P) / Voltage (V).

So, to derive the current from KVA:

1. Convert KVA to watts (KVA x 1000).

2. Divide by the voltage.

This results in the formula: Current (I) = (KVA x 1000) / Voltage, confirming that the use of KVA multiplied by 1000 divided by voltage is essential for this calculation. This understanding reflects how electrical systems are interconnected