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If you are asking whether power-factor improvement has any effect on a wattmeter reading, then the answer is no, it doesn't. Improving the power factor of a load has absolutely no effect on the power of the load, but it can act to reduce the value of the load current.
Wiki User
∙ 12y ago
Wiki User
∙ 11y agoNone. A wattmeter measures the supply voltage and the in-phase ('resistive') component of the load current, so will always indicate the true power of a load, in watts, regardless of the load's power factor.
Anonymous
It depends what you are holding constant.
If the PF is 1.0, the load is pure resistive. The current is in phase with the voltage, and there is no reactive component. The kVA will equal the kW.
If the PF < 1.0, the load is partially reactive. The current is not i phase with the voltage. The kVA will be greater than the kW.
So for a given current (and given kVA), with a lower PF, the watts shown on a wattmeter will be lower.
But for a given number of watts or kW, a lower PF will not affect the wattmeter,
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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.
What effect does the power factor obtained from the reactive loads have on the wattmeter reading being negative?
A wattmeter measures the supply voltage and the in-phase component of the load current and, therefore, its reading is unaffected by the power factor of the load. In other words, it will always read true power regardless of power factor.If it is reading backwards, it is because the polarity markings have been ignored and either the voltage coil or the current coil have been connected the wrong way around.
Is it possible to measure power factor of the balanced three-phase load by two-wattmeter method?
yes.
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
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.
What is the effect of variation of power factor on readings of two wave meters used in 3 phase power mesurements?
I assume that you mean 'watt meters', and not 'wave meters', in this question, and that you are referring to the 'two wattmeter method' of measuring the power of a three-phase load.Variations in power-factor will cause the ratio of the two wattmeter readings to vary, but the sum* of those readings will always indicate the total power of the load. Providing the load is balanced, you can use the ratio of the two wattmeter readings (P1 and P2) to determine its power factor, based on the following equation:phase angle = tan-1 {1.73[(P2 - P1) / (P2 + P1)]}Where power factor is then the cosine of the phase angle determined by this equation.[*If one or other of the wattmeters is reading 'downscale' -backwards- then it will be necessary to reverse the connection to that instrument's voltage or current coil.]
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.
What is low power factor watt meter?
A wattmeter reads the true power of a load, regardless of its power factor.
What does upf stands in upf wattmeter?
Unity Power Factor.
How is the power factor of an Electrodynamometer type wattmeter improved?
Power Factor of an electrodynamometer can be improved by connecting a large resistor in series with the current coil.
Is there any difference in values between the two wattmeter method and three wattmeter method if you apply these two methods in same load?
Blondel's Theorem states that you can have one less wattmeter than there are conductors supplying a balanced or unbalanced load. In either case, the sum of the wattmeter readings will give you the total power of the load.
How you measure power factor in three phase load by two wattmeter method?
First of all, you can only measure power factor of a three-phase load, provided that it is balanced load. The power factor can then be found by determining the cosine of the phase angle, using the following equation:tan (phase angle) = 1.732 ((P2-P1)/(P2+P1))...where P1 and P2 are the readings of the two wattmeters.
What effect does the power factor obtained from the reactive loads have on the wattmeter reading being negative?
A wattmeter measures the supply voltage and the in-phase component of the load current and, therefore, its reading is unaffected by the power factor of the load. In other words, it will always read true power regardless of power factor.If it is reading backwards, it is because the polarity markings have been ignored and either the voltage coil or the current coil have been connected the wrong way around.
Is it possible to measure power factor of the balanced three-phase load by two-wattmeter method?
yes.
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
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.
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.
