3 phase motor kwh calculation pdf

For three wire, two phase circuits, the current in the common conductor is 1. For ac 3 phase motor how can i calculate power in kwh. This video is about 3 phase motor amps calculation or 3 phase motor current calculation guide. Motor load reference ac and heat pumps running load starting load description hp running kw singlephase threephase singlephase threephase kw amps at 240 v amps at 208 v amps at 240 v amps at 480 v lr amps at 240 v lr amps at 208 v lr amps. Jul 29, 2007 if you use the 220 v linetoline voltage, 4. The torque is the twisting force that makes the motor running and the torque is active from 0% to 100% operating speed. To find the phase current rating if the 50hz load kw or kva is known, select the known kva or kw rating on the chart above. Electrical horsepower is used for electric engines and air conditioners. What size genset is needed to start a 3 phase electric motor direct on line dol start. So it mainly comes down to the cost of the motors and the cost to run the motors. Kw, kva kw is real consumed power turned into heat, and is the product of volts x current x power factor.

Last time i write about the single phase em wiring and in this post i am writing about the 3 phase kwh meter wiring and its connection diagram. Use the chart in this calculation guide to find the formula you need according to the measure. Input power calculation an existing motor is identified as a 40hp, 1800 rpm unit with an open dripproof enclosure. In 3phase you have the current divided across the phases. Calculating and measuring power in three phase circuits.

The diagonal of that parallelogram shows the vector difference of i r and i b which is equal to current in line 1 i 1. Amperage of 3 ph generators amperage 120208 3 ph, 80% pf kw x e x pf x 1. How do i calculate the power consumption for a 3 phase motor. One single phase wattmeter plus miscellaneous apparatus as needed. Energy usage calculation on 3 phase the science and. For greater ease we explain that formula is used for the calculation and a table with the main conversions of kw to kwh in conversions from kw to kwh. A 3 phase power circuit consists of three conductors of alternating current combined into a single power line. The equation is w av sqrt 3 where a is amperes, v is volts, and sqrt 3 is the square root of 33 about 1. To calculate 3 phase kwh from measuring amps on each phase free download as.

Convert ptotal from kva into kilowatts using the formula. In a threephase 120 system, only 3 wires are required to. Rt 3 x v x i for 100% load ii for 50 % load i 50100 x i i2 i is the rated current of the machine. Amperage of 3 ph generators amperage 120208 3ph, 80% pf kw x e x pf x 1. It will definitely have a nonzero inductance, and hence a power factor associated with it. Kwh calculations for a balanced 3 phase circuit all. The power factor for full load operation may be on the motors nameplate. The power factor for full load operation may be on the motor s nameplate. Free online calculation of electrical power and energy. Kwh calculations for a balanced 3 phase circuit all about.

You already have the phase perfect, so that money is already spent. How to calculate 3 phase motor power consumption it still runs. Multiplying that, as you noted, would give me the watts of a 3 phase circuit assuming the power factor is 1. Inverter systems are a common feature in our homes and workplace where they play a prominent role in the ensuring uninterruptible power to sensitive loads and devices. As you know that we use two types of electrical appliances regarding its rated voltage, in which some are for single phase and some are required 3 phase, just like this we use two types of kwh meter in. Motor formulas and calculations, index of helpful tools.

P1 v1 x i1 300v x amps 39,000 va or 39 kva p2 v2 x i2 280v x 120 amps 33,600 va or 33. The power produced by the motor depends on the speed of the motor and is. Feb 12, 2018 this video is about 3 phase motor amps calculation or 3 phase motor current calculation guide. In the video i complete explained about how to calculate 3 phase motor current or how to calculate. The calculators below can be used to calculate electric motor amps, horsepower and 3phase kva. With the load balanced, and the three currents phase shifted by 120 from each other, the sum of the current at any instant is zero and there is no current in the return line. Amps to kilowatts kw conversion calculator rapidtables. The current i in amps a is equal to times the power p in kilowatts kw, divided by the voltage v in volts v. Use if all 3 phases pull the same amount of current individual 3phase current measurement phase to neutral. Once you sort this out you can get the efficiency be dividing the output power by the input power. Most electric motors are designed to run at 50% to 100% of rated load. How to calculate cost of electricity for electric motor 3. P1, p2, p3 power of phase 1, phase 2 and phase 3 in watt w v voltage in volt v exemple.

Use the chart in this calculation guide to find the formula you need according to the measure you will calculate. Calculating and measuring power in three phase circuits 1. Calculating electric cost of motors and equipment 30 minutes. Motor energy savings calculation form, to determine the cost effectiveness of motor changeout options. Electrical 3phase and single phase power,current and energy. Figure 3 relationships between power, current, power factor and motor load example.

Calculate three phase motor power consumption by multiplying amps by volts by the square root of three w avsqrt 3. An operating three phase motor has voltages measured with a voltmeter on each. You can make ads in the engineering toolbox more useful to you. Use the chart in this calculation guide to find the formula you need according to the measure you will. The current in each conductor is cycle out of phase with the other two. One mechanic or hydraulic horsepower is equal to 0. Rotating flux is only possible when 3 phase voltage or poly phase which is 120 degree apart in time is applied to a three phase winding or poly phase winding 120 degree apart in space then a three phase rotating magnetic flux is. Find the best 1phase and 3phase motor that fits your application and then do the power calculation for each and compare. How do you calculate 3 phase kwh from measuring amps on. Fla full load amps amount of current drawn when fullload torque and horsepower is reached for the motor. V1230 v in 400 v threephases circuit i1, i2, i3 current of phase 1, phase 2 and phase 3 in ampere a cos. Most singlephase applications will be for residential and small commercial buildings balanced 3phase power measurement. Find the best 1 phase and 3 phase motor that fits your application and then do the power calculation for each and compare. Amperage measured on each phase with an ammeter are 10, 25, and 16 amps, power factor is assumed as 0.

Find the kw consumption of the following 3phase motor circuit that has a voltage of 230 vac, a current draw of 75 amperes and a power factor rating of. You should also make a dc measurement of stator winding linetoline resistance. Can i calculate the efficiency of a 3 phase motor using the formula w. As you know that we use two types of electrical appliances regarding its rated voltage, in which some are for single phase and some are required 3 phase, just like this we use two types of kwh meter in which one for. For example, if the electric motor uses 50 amps at 240 volts, the wattage is 50 x 240 x 1. Calculation of ac three phase amps to kilowatts line to line voltage p kw v3 x pf x i a x v ll v, which means that the power in kilowatts is calculated by the square root of three multiplied by the power factor times the phase current in amps by the line to line voltage rms. Although electrical service to residential buildings in the usa are exclusively by single phase circuits, electrical. Motor guide february 2014 low voltage motors motor guide. To find the power given current, multiply by the voltage and then the power factor to convert to w. This improves power line efficiency and provides the smooth power flow required by many such motors.

I have the input power1600 watts, input voltage460 volts, rated current 2. How to calculate inverter power rating and inverter. Formulae for calculating amperes, horsepower, kilowatts. Kva is apparent power, is always greater than or equal to kw and is the product of volts x amps 1 phase, volts x amps x, v3, 3 phase. How to calculate cost of electricity for electric motor 3 phase. With measured parameters taken from handheld instruments, you can use equation 1 to calculate the three phase input power to the loaded motor.

The 3 phase electric motor is usually a large piece of equipment that uses a polyphase. The current of line 1 can be found by determining the vector difference between i r and i b and we can do that by increasing the i b vector in reverse, so that, i r and i b makes a parallelogram. In 3 phase you have the current divided across the phases. Scan across the row to the right until the three phase ll line to line voltage being utilized column is reached. Formula to calculate power, current and voltage in threephase wiring balanced. This arrangement produces a smoother power flow and permits lower line voltages. For a three phase system multiply by three to get the total power. For threewire, two phase circuits, the current in the common conductor is 1. You only need to fill in the columns colored in orange. Oct 28, 2018 in this video we calculate 3 phase induction motor load, as we know we need to run 3 phase motor, one starter, cable, circuit and all this component ratting in ampere so we should know how much. Fill in the hp of the motors in their starting sequence, select the start method direct on line or star delta and. In a motor you have to factor in the power factor 1 or less and the effects of the 3phase wiring. And since 3 divided by the sq root of 3 simplifies to just the sq root of 3.

Refer to operational specifications to find the power factor. Also make sure you use the larger voltage of the system voltages, ex if. The current in each conductor is 1 3 cycle out of phase with the other two. For 3 phases, then, the total power is 3 times the power in any phase. If you find this website valuable and appreciate it is open and free for everybody please contribute by. Motors, power, and data loggers greg jourdanwenatchee valley. Select horsepower unit type, enter the power in horsepower and press the convert button. Introduction the generation and transmission of electricity is commonly accomplished by means of three phase circuits. For home applications, there is the need to adequately size your inverter to be able to meet the expected load demand. The power p in kilowatts kw is equal to square root of 3 times the power factor pf times the phase current i in amps a, times the line to line rms voltage v ll in volts v divided by. Scan down this column to the current needed for your application select the next higher current rating for more margin. Calculate threephase motor power consumption by multiplying amps by volts by the square root of three w avsqrt 3.

A 3phase power circuit consists of three conductors of alternating current combined into a single power line. Below is the most common inner connection of of 3phase energy meter. Calculation of power and energy of electrical circuit 3phases or single phase. If the motor is operating considerably below rated load, the power factor could be much lower. How to calculate 3 phase motor power consumption it. Determining electric motor load and efficiency energy efficiency. Record all nameplate information for the induction motor. With measured parameters taken from handheld instruments, you can use equation 1 to calculate the threephase input power to the loaded motor. Difference is that transformer is an alternating flux machine while induction motor is rotating flux machine. Below is the connection of 3phase three phase or poly phase 3phase,4 wire kwh meter digital or analog energy meter from the supply to the main distribution board. In this video we calculate 3 phase induction motor load, as we know we need to run 3 phase motor, one starter, cable, circuit and all this component ratting in. The phase current i in amps a is equal to times the power p in kilowatts kw, divided by the power factor pf times the rms. The 3 phase electric motor is usually a large piece of equipment that uses a polyphase circuit to draw heavy power loads at relatively low voltages. To calculate kva, you need to enter the known values of voltage and the current into the respective fields.

Hi can i calculate the efficiency of a 3 phase motor using the formula w. For example, if the motor is drawing 30 amps at 250 volts, you have 30 x 250 x sqrt 3 about 1. Rotating flux is only possible when 3 phase voltage or poly phase which is 120 degree apart in time is applied to a three phase winding or poly phase winding 120 degree apart in space. Kilowatts to amps a conversion calculator rapidtables. Find the kw consumption of the following 3 phase motor circuit that has a voltage of 230 vac, a current draw of 75 amperes and a power factor rating of. But for this case its a condenser its got a big three phase motor in it. The power factor is a ratio its actually the cosine ratio of the impedance triangle in our example above 12. Jan 21, 20 in a motor you have to factor in the power factor 1 or less and the effects of the 3 phase wiring.

One singlephase wattmeter plus miscellaneous apparatus as needed. Formulae for calculating amperes, horsepower, kilowatts, and. Multiply the power consumption by the hours of operation to find kilowatt hours. Calculation of ac three phase amps to kilowatts line to line voltage p kw v3 x pf x i a x v ll v, which means that the power in kilowatts is calculated by the square root of three multiplied by the power factor times the phase current in amps by the line. Calculate the total 3 phase power, or ptotal, by adding the power of each phase together. How to calculate unit consumption on the basis of load. Convert watts to kilowatts by dividing the number of watts by 1,000. Ac three phase amps to kilowatts calculation calculation with line to line voltage. Generator sizing guide power management solutions eaton. Scan the row to the left and find the kva and kw rating needed.