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What effect does the power factor obtained from the reactive loads have on the wattmeter reading being negative?
Wiki User
∙ 11y ago
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.
Wiki User
∙ 11y ago
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Why wattmeter shows negative reading during no load condition of 3phase ac induction motor?
no load means the motor is acting like a coil
What is effect of power factor on the readings of wattmeter?
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.
What does reading of wattmeter indicate in case of open circuit test of transformer?
In case of open circuit test of transformers we measure iron losses and hence the power lost here is being measured by the wattmeter.
What if you have a negative kvar reading?
A negative KVAR reading can be eliminated by adding an inductor to the circuit.
Why does an AC wattmeter require polarity marking?
To ensure that the relative directions of the current passing through the current and voltage coils result in the meter reading 'upscale'.
Why wattmeter shows negative reading during no load condition of 3phase ac induction motor?
no load means the motor is acting like a coil
What is effect of power factor on the readings of wattmeter?
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.
What does reading of wattmeter indicate in case of open circuit test of transformer?
In case of open circuit test of transformers we measure iron losses and hence the power lost here is being measured by the wattmeter.
What happens to the meter reading when you invert the direction of the arrow on the current transformer of power meter?
The wattmeter will read downscale (backwards).
What if you have a negative kvar reading?
A negative KVAR reading can be eliminated by adding an inductor to the circuit.
Why is pilot reading so called?
The first reading which is obtained after end point.
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 does an AC wattmeter require polarity marking?
To ensure that the relative directions of the current passing through the current and voltage coils result in the meter reading 'upscale'.
What is meant by the active and reactive powers in electricity?
These terms describe the behaviour of energy in alternating-current circuits.Active power (also known as 'true power' or 'real power') describes the rate at which energy is permanently dissipated by the resistive component of a circuit or load. Active power is measured in watts.Reactive power describes the rate at which energy is alternately stored in the magnetic or electric field and, then, returned to the source when the field collapses, during every quarter-cycle. Reactive power is measured in reactive volt amperes.Apparent power is the vector sum of a circuit's active and reactive power, and is measured in volt amperes.The apparent power of an a.c. load can be determined from the product of a voltmeter and an ammeter reading. The active power can be determined by using a wattmeter. The reactive power can then be determined by vector subtraction.
Can reading something negative cause you to be negative?
Yes, it is possible. Hanging out with friends or people that have very negative attitudes can also cause you to be negative.
Can drugs give you a negative pregnancy reading?
hi
What does a negative decibel reading indicate?
figure it out youself
