Motor current ratings based on kilowatt output at 120, 208, 240, 277, and 480 volts three-phase AC with an efficiency of 0.8 and a power-factor of 1. of 0.9 Motor Current Ratings (Three-Phase AC) Table 3 – Single Phase AC Kilowatts to Amps (kW to Amps) at a P.F. Here is the table for single-phase AC Kilowatts to Amps (kW to Amps) at a power factor of 0.9 in 120 and 240 volts single-phase AC for power 1 kW to 1000 kW: Power (kW) Table 2 – DC Kilowatts to Amps (kW to Amps) Single Phase AC Kilowatts to Amps (kW to Amps) at a P.F. Here is the kW to Amps Conversion Table at 110 VDC and 220 VDC for 1 kW to 1000 kW: Power (kW) joule J 1 kilojoule kJ 1000 joule J kilojoule to joule, joule to kilojoule.
Table 1 – typical power factor values kW to Amps Conversion Tables DC Kilowatts to Amps (kW to Amps) Complete list of energy units for conversion. Here are typical power factor values in table: Device/Loadįluorescent lighting (electronic ballast) The formula states that the phase current is equal to 1000 times the power in kilowatts, divided by 3 times the power factor and the line to neutral RMS voltage. Table 2 lists each 3-phase constant for the respective 3-phase voltage obtained from the above calculation.This formula relates the phase current I (in amps) to the power P (in kilowatts), power factor PF, and line to neutral RMS voltage VL-N (in volts). 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. 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: 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.
Kw to amp conversion how to#
We'll also show you how you can do these calculations “in your head,” with very reasonable accuracy, through the use of constants. How to calculate amps from kilowatt Calculation of Direct Current Kilowatts to amps: I (A) 1000 x P (kW) / V (V).
This month, we'll discuss the most fundamental of calculations - those for current (I) and kilowatts (kW).
Kw to amp conversion series#
Welcome to the first in a series of articles focusing on electrical calculation basics.
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