In exactly the same way as you do so for a single-phase load. It's the product of the power of the load, expressed in kilowatts, and the during of operation, expressed in hours. (And the symbol of kilowatt hours is 'kW.h', not 'kwh')
There is software that can be downloaded to help calculate the number of turns for a three phase motor. There are also diagrams which can be found for the most frequently used calculations.
A 7.5 kW three phase load will be balanced by the manufacturer. When connected to a three phase source the line current on each phase will be equal.
Single phase power from a L-L voltage of 208 volts is calc'd: P = V(phase to phase) * I (individual phase current) / sqrt(3) Total power from all three legs is the above P * 3. P is in watts; continuous sampling will result in watt hour measurements; 1000 x this is kWh's.
If you have three adjacent houses each with a single-phase supply taken from different phases in a three-phase cable in the street, the total power is equal to the sum of the powers in each of the three phases.
output power/Rated power
No, a single phase kWh meter is designed to measure the energy consumption of single phase loads only. To measure the energy consumption of a three phase load, you would need a three phase kWh meter specifically designed for that purpose. Using a single phase meter for a three phase load would not provide accurate energy consumption readings.
To convert amps to kilowatt-hours (kWh) for a three-phase system, you need to know the voltage. The formula for three-phase power is: Power (kW) = sqrt(3) x Voltage (V) x Current (A) x Power Factor. Once you have the kW, you can convert to kWh by multiplying by the number of hours the equipment operates.
You can't. Measure the amperes simply tells you what the current is.
Measuring the current in each phase (or do you mean 'line'?) will not give you sufficient information to work out what you are asking for.
It depends on the voltage. Please restate the question and provide the voltage. In general, however, simply divide total power by KV to get KA. Remember the KWH is an integral, so you need to back calculate KW. If the month is a 30 day month, then KW is KWH / 30 / 1440. Then, if the load is star, simply divide by three; if the load is delta, divide by three and multiply by 1.732, the square root of 3. Example: 480 three phase running star. 8000 / 30 / 1440 is 185 amperes. 185 divided by 3 is 62 amperes per phase. For delta, that becomes 107 amperes.
To calculate the kWh consumed by a 3-phase motor, you'll need to know both the power factor and operating hours. The formula is: kWh = (√3 x Volts x Amps x Power Factor x Hours) / 1,000. Without the power factor and hours of operation, a precise kWh calculation cannot be provided using just voltage and current.
To calculate three-phase meter reading in kWh with CT coils, you need to first determine the current ratio provided by the CT coils. Multiply the current readings obtained from the CT coils with the current ratio to get the actual current values. Then, multiply the actual current values with the voltage and power factor to get the power in each phase. Finally, sum the power in each phase and multiply by the time in hours to get the kWh reading.
There is software that can be downloaded to help calculate the number of turns for a three phase motor. There are also diagrams which can be found for the most frequently used calculations.
You are, presumably, talking about an unbalanced three-phase load. The answer is no, because the wattmeter takes unbalanced loads into account.
You will need to determine the power per phase, and add them up to give the total power of the three-phase load. To do this, you will need to multiply the phase-voltage by the phase current by the power factor -for each phase.
The formula you are looking for is - phase voltage/1.73 = phase to neutral voltage.
To calculate the cost per kWh given 35 kWh of usage and the total cost, divide the total cost by the number of kWh. For example, if the total cost is $70 for 35 kWh, the cost per kWh would be $70 / 35 kWh = $2 per kWh.