
Table 2 lists each 3-phase constant for the respective 3-phase voltage obtained from the above calculation. Now, if you look at the “1,000 ÷ 1.732V” portion of this equation, you can see that by inserting the respective 3-phase voltage for “V” and multiplying it by 1.732, you can then divide that resulting quantity into “1,000” to get a specific number (or constant) you can use to multiply “kW” to get the current draw of that 3-phase load at the respective 3-phase voltage. There are several calculations you can perform using this calculator over a short period. If you have a piece of equipment that draws 80A, then you can calculate the relative size of the required power source, which is 10kW (80 ÷ 8.33).īy using this same procedure but inserting the respective single-phase voltage, you get the following single-phase constants, as shown in Table 1.įor 3-phase systems, we use the following equation:Īgain, assuming unity PF and solving this equation for “I,” you get: This procedure is simple and will require you to enter the right units of Kilovolt-amps in the required text field. So, if you have a 10kW load, you can calculate the current draw to be 83.3A (10 × 8.33).

Now, if we look at the “1,000 ÷ V” portion of this equation, you can see that by inserting the respective single-phase voltage for “V” and dividing it into the “1,000,” you get a specific number (or constant) you can use to multiply “kW” to get the current draw of that load at the respective voltage.įor example, the constant for the 120V calculation is 8.33 (1,000 ÷ 120). Single-Phase Calculationsīasic electrical theory tells us that for a single-phase system,įor the sake of simplicity, let's assume the power factor (PF) is unity. You can use constants that apply to specific single- and 3-phase voltages to calculate current (I) and kilowatts (kW). No matter what the circumference and diameter of the respective circle, their ratio is always pi. You may ask, “What exactly is a constant?” An example of a constant with which you're very much familiar is pi (π), which is derived by dividing a circle's circumference by its diameter. Watts (W) to kilovolt-amps (kVA) calculator. We'll also show you how you can do these calculations “in your head,” with very reasonable accuracy, through the use of constants. This month, we'll discuss the most fundamental of calculations - those for current (I) and kilowatts (kW).
#KVA TO WATTS CALCULATOR SERIES#
Welcome to the first in a series of articles focusing on electrical calculation basics.
