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Take the current average of the three lines.

Ex.

Phase A = 10Amps

Phase B = 9 Amps

Phase C = 11 Amps

Average = 10Amps

Take the voltage average of the three lines to ground,

Phase A = 460V

Phase B = 450V

Phase C = 470V

Average 460V

Power = V*I (Voltage times Current)

Since we have a AC circuit,

Power = V*I*1.732

Comment

Unfortunately, the above equation for power only works if you use line voltage; your explanation describes phase voltages. And, of course, it doesn't take power factor into account.

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Q: How measure 3phase power without wattmeter?
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Why does not wattmeter measure the reactive power?

A wattmeter is designed so that it measures the supply voltage and the in-phase component of the load current. The product of these two quantities is the true power of the load.


What instrument can you use to measure reactive power of a load?

An ammeter and a wattmeter are the instruments needed.


How would you measure power factor of the balanced three phase load by two wattmeter method?

Yes. The wattmeter's current coil will have to be connected into one of the line conductors, and its voltage coil between that same line conductor and the neutral point of the load. Connected this way, the wattmeter's voltage coil is measuring one of the three phase voltages (line-to-neutral voltage) while its current coil is measuring the corresponding phase current (for a 4-wire system, the phase current = line current). The power factor (cosine of the phase angle) is accounted for automatically within the wattmeter. So the wattmeter will measure the true power (in watts) of one phase. The total power, therefore, will be 3x the wattmeter reading -providing, of course, that the load is balanced (i.e. each phase is identical). WebRep currentVote noRating noWeight


How would you measure power using three watt meter and one watt meter for balanced and unbalanced loads?

The 'one wattmeter method' can only be used for balanced, wye-connected, loads where the load's neutral point is accessible. The wattmeter's current coil is inserted into any line conductor, and the voltage coil is connected between the same line and the neutral point. The wattmeter reading indicates the power of one phase, so the total power is three times the wattmeter reading.To measure the total power of a balanced or unbalanced wye- or delta-connected load, it is only necessary to use twowattmeters -this is called the 'two wattmeter method'. In this case, the current coils of each wattmeter are inserted into any two line conductors, and the voltage coils are connected between the two line conductors and the third line conductor. The sum of the two wattmeter readings will indicate the total power of the load.


Why use two wattmeter to calculate the power of a three phase load?

Two wattmeter method is used in a three phase sysstem to measure the true power without regard to the balance ie. It can be used to measure both balanced loads and unbalanced loads.The three phase power could be measured using single phase wattmeters in each loads of the system. But using three wattmeters is quite unnecessary as we can measure it by using only two wattmeters.The three phase power could be measued by using single phase wattmeters , haing a current coil in one line and a potential coil connected between the line and some arbitrary common junction point. If that arbitrary common point is chosen on one of the three lines, then the wattmeter connected to that line will indicate zero power because it's potential coil has no voltage across it. hence, that wattmeter may be eliminated, and the three phase power can be determined by means of only two single phase wattmeters.

Related questions

Can reactive power measure by 2 wattmeter method?

Active volts amperes are measured by 2 wattmeter methods. A wattmeter will measure active power and not reactive power. Electrical engineering is a promising career for anyone who likes to generate power.


Why wattmeter measure the reactive power?

A watt meter will measure active power, not reactive power.


To measure electrical power you would use a?

wattmeter


What is the function of watt meter?

The wattmeter is an instrument to measure the electrical power.


What are the uses of wattmeter?

Wattmeter is an intrument which is used to measure the power consumption of an Electric circuit or an appliance which is connected to the supply in terms of Watts.


What quantity is watt measured in?

A wattmeter is used to measure the power of a load.


Why does not wattmeter measure the reactive power?

A wattmeter is designed so that it measures the supply voltage and the in-phase component of the load current. The product of these two quantities is the true power of the load.


What instrument can you use to measure reactive power of a load?

An ammeter and a wattmeter are the instruments needed.


Is it possible to measure power factor of the balanced three-phase load by two-wattmeter method?

yes.


Why watt-meter is required to measure real power delivered to a purely resistive load?

A wattmeter (not 'watt-meter') will always measure the true power of a load, regardles of whether that load is purely resistive or not. This is because a wattmeter effectively measures the in-phase component of the load current.


What is difference between lpf and upf wattmeters?

LPF wattmeter is used for measuring power in highly inductive circuits & UPF wattmeter is used for measure power in resistance circuit in which the power factor ranges from 0.5 to unity. Answer is given by :Er. M KUMAR YADAV


Why you use low power factor wattmeter on primary and unity power factor on secondary side of transformer?

There is no such thing as a 'low power-factor' wattmeter. A wattmeter always reads true power, regardless of the load's power factor.