The instrument that measures the low value of power factor accurately is known as the Low Power Factor Wattmeter (LPFW). The low power factor meter is used. So LPF(Low Power Factor) Wattmeter is used in OPEN CIRCUIT TEST of Transformer. In short circuit test the secondary winding of transformer. 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.
|Published (Last):||9 June 2007|
|PDF File Size:||8.35 Mb|
|ePub File Size:||1.48 Mb|
|Price:||Free* [*Free Regsitration Required]|
It is also used in the resistive circuit which has a power factor range from 0.
As secondary side is short circuited the entire coil will be purely resistive in nature. Lpf is used in power measuring in high inductive circuit and upf is used in power measuring in resistance circuit which power factor ranges 0. What is analog wattmeter?
Now there are two main reasons that would suggests us that we should not use ordinary wattmeter in measuring the low value of power factor. What is Low Power Factor Wattmeter? Get Best Price Request a quote.
How does a wattmeter work? What does upf stands in upf wattmeter? It is the second modification that we have discussed in detail above. LPF is Low power factor, which is used to calculate overall power in VA voltamps kind of like calculating overall power in watts.
Auto Ranging Digital LPF Watt Meter, Mumbai, India
Compensation for Inductance of Watgmeter In low power circuit, the value of current is high, and that of the power is low. The supply voltage is equal to the voltage across the pressure coil.
A modern low power factor meter is designed such that it gives high accuracy while measuring power factors even lower than 0. Thus wattmmeter order to avoid this situation we have connect the variable series resistance with a capacitor as shown in the above figure.
Calibration of LPF wattmeter by phantom loading? The pressure coil circuit is designed to have a low value of resistance, so that the current flowing through it is increased to give an increased torque.
Electromechanical meters are described below.
In the wartmeter category both the ends of the pressure coil is connected to supply side i. Blondel’s Theorem states that you can have one less wattmeter than there are conductors supplying a balanced or unbalanced load. Owing to our quality approaches and transparent business dealings, we have acquired a huge client-base all over the country. When current flows it is induced onto the coils which causes a rotor to roate inside the stator casing of the meter.
Low Power Factor Wattmeter
What is ac wattmeter? In the first category both the ends of the pressure coil is connected to supply side i. Electrodynamometer wattmeter and Low Power Factor LPF wattmeters are mostly similar in construction and operation, except for the following modifications are carried out in the electrodynamometer wattmeter to convert it into a LPF wattmeter: LPF is a low pass Llf filter which passes the low frequency signals and reduce the amplitude of the signals with frequencies higher than the cutoff frequency.
The compensation of the error caused by the inductance in the pressure coil is done by connecting a capacitor across a part of series resistance in the pressure coil circuit.
The pressure coil current I p flows through it. Acknowledged for their dimensional accuracy, light weight and compact design, our products are widely used for various applications in the field of basic electronics, power electronics, analogue communication, digital communication and many other areas. Please enter the OTP sent to your mobile number: Circuit Globe All about Electrical and Electronics.
Our organization wattmdter specialization in customizing these products in accordance with the specifications mentioned by the clients. Thus the error occurs in the pressure coil is neutralized. In open circuit test the secondary winding of transformer is kept wattmetef.
F meter in parallel. Year of Establishment The pressure coil is placed such that the field produced by the compensating coil is opposed by the field produced by pressure wxttmeter as shown in the above circuit diagram.