Electrodynamometer type wattmeter construction and working. This device is available in a purely electronic form too which is known as digital wattmeter. Dynamometer type wattmeter engineering notes dynamometer type wattmeter. It is important to avoid excessive current flow in the voltage and current coils of a wattmeter. Dynamometer wattmeter electrical engineering assignment. Electrodynamic instrument a measuring instrument whose operation is based on. For example, in using an electrodynamic wattmeter on direct current, two readings are taken, the direction of current flow through the instrument being reversed.
The fixed coil is connected in series to the circuit whose power consumption is to be calculated. The fixed current coils are wound with a few turns of a relatively large conductor. Electrodynamometer wattmeter consists of two coils, pressure coil pc and current coil cc. An electrodynamic instrument connected as a wattmeter, with the main current flowing through the fixed coil, and a small current proportional to the voltage flowing through the movable coil. They are used as wattmeters, voltmeters and with some modification as power factor meters and frequency meters.
Electrodynamometer type wattmeter in general, a watt meter is used to. Before we study the internal construction of electrodynamometer wattmeter, it very essential to know the principle of working of electrodynamometer type wattmeter. The device consists of a pair of fixed coils, known as current coils, and a movable coil known as the potential coil the current coils are connected in series with the circuit, while the potential coil is connected in parallel. En8592 notes wastewater engineering regulation 2017. This manual covers direct and general support maintenance for wattmeter me82u fig. Therefore this fixed coil is often called current coil cc.
Electrodynamic instrument article about electrodynamic. The fixed coils or field coils arc connected in series with the load and so carry the current in the circuit. In these wattmeters, the field produced by the currentcarrying moving coil tries to come in line with the field produced by the currentcarrying fixed coil, and a deflecting torque is exerted on the moving system. Pressure coil is connected across the circuit whose power is to be measured and current coil is connected in series.
Construction of electrodynamometer wattmeter fixed coils the fixed coils carry the current of the circuit. Electrodynamometer electrodynamics type instruments. Wattmeter electric power is measured by means of a wattmeter. The two coils are connected in different circuits for measurement of power. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamo meter wattmeter. The traditional wattmeter was an electrodynamometer instrument with a rotating potential coil of many turns and a fixed current coil of a small number of turns.
Wattmeter design chapter 8 dc metering circuits pdf version. If two coils are connected such that, current proportional to the load voltage, flows through one coil and current proportional to the load current, flows through another coil, the meter can be calibrated directly in watts. Electrodynamometer type, induction type, single phase and three phase wattmeter, compensation, energymeters. Electrodynamometer type instruments pdf the electrodynamometer type instrument is a transfer instrument. Electrodynamometer type wattmeter working principle. This is one of the advantages of this type ofmeter. It uses for measuring the power of both the ac and dc circuits. Measurement of threephase power with the 2wattmeter. Pdf implementation of a digital wattmeter on fpga researchgate. At zero power factor, corresponding to a purely reactive load, both wattmeters will again have the same wattage indication but with the opposite signs, so that their algebraic sum will yield zero power absorbed, as it should. Electrodynamometer type instruments free download as powerpoint presentation. Also, on analog wattmeters, the potential coil carries a needle that moves over a scale to indicate. Power factor meters electrodynamometer type power factor. For the love of physics walter lewin may 16, 2011 duration.
Dynamometer type wattmeter works on very simple principle and this principle can be stated as when any electric current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due this mechanical. The traditional form of wattmeter is called as dynamometer wattmeter. A electro dynamometer wattmeter is used for the measurement for d. Electrodynamometer type instruments alternating current. The general circuit diagram of single phase electrodynamometer power factor meter is given below. Electrical and electronics measurements and instrumentation kelm. These instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. Wattmeter are illustrated in figure 21, and the functions of these elements are described in table 21. Now the pressure coil is split into two parts one is purely inductive another is purely resistive as shown in the diagram by resistor and inductor. Hence moving coil is connected across the voltage and. The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the electrodynamometer wattmeter.
Dynamometer type wattmeter works on very simple principle and this principle can be stated as when any current carrying conductor is placed inside a magnetic field, it experiences a mechanical force and due to this. The transition from a negative to a positive value occurs. Electrodynamic type instruments are similar to the pmmctype elements except that the an electrodynamometer for use as a wattmeter is shown in fig. Wastewater engineering notes en8592 pdf free download.
This is a online courseware website for sns college students through this website student can access their materials. For more details about electrodynamometer type wattmeter click here. A dynamometer type wattmeter is most commonly employed for measurement of power in a. Wattmeter design dc metering circuits electronics textbook. Electrodynamometer types of instruments are used as a. To see other topics in basic electrical and electronics engineering click here. If the coils are connected so that a value of current proportional to the load voltage flows in one, and a value of current proportional to the load current. The current coils of the two wattmeters are connected in series on any two lines and the third line on which no wattmeter is connected. Week 03 electrodynamometer as wattmeter ece2 3t 201415 free download as pdf file. Electrodynamometer wattmeters a media to get all datas. Week 03 electrodynamometer as wattmeter ece2 3t 201415.
A transfer instrument is one which is calibrated with a d. As shown in figure 318, it consists of a pair of fixed coils, known as current coils, and a moving coil, called the voltage potential coil. The electrodynamic wattmeter, shown in figure 310, uses the reaction between the magnetic fields of two currentcarrying coils. Electrodynamometer wattmeters these instruments are similar in design and construction to electrodynamometer type ammeters and voltmeters. The supply voltage is equal to the voltage across the pressure coil. The working principle of the electrodynamometer wattmeter is very simple disturbs the main magnetic field of the electrodynamic wattmeter. Click here to download the pdf of this topic electrodynamometer type wattmeter. Since the moving coil carries a current proportional to the voltage, it is called the pressure coil or voltage coil or simply called p. Single phase electrodynamometer type wattmeter the instrument used to measure active power p drawn by a load or circuit is called watt meter.
Dynamometer type wattmeter construction and working. Electrodynamometer type wattmeter when a moving coil that is free to rotate is kept under the influence of a current carrying conductor, then automatically a mechanical force will be applied to the moving coil, and this force will make a little deflection of the moving coil. Electrodynamometer type instruments download as powerpoint presentation. Electrodynamometer type wattmeter electrodynamometer type wattmeter in general, a watt meter is used to measure the electric power of a circuit, or sometime it also measures the rate of energy transferred from one circuit to another circuit. Dynamometer type wattmeter working your electrical guide.
It includes instructions for troubleshooting, testing, and repairing of the me82u, and replacing maintenance parts. Electrodynamometer wattmeter pdf and can moves freely. Electrodynamometer type wattmeter electrical study app. The two wattmeter is used for the power measurement in the 3 phase system, irrespective of whether the load is balanced or unbalanced, star or delta connected. Electrodynamometer wattmeter pdf electrodynamometer wattmeter consists of two coils, pressure coil pc and current coil cc. The traditional analog wattmeter is an electrodynamic instrument.
An electrodynamometer wattmeter have two types of coils. The dynamometer wattmeter works on the motor principle. We will discuss electrodynamometer type wattmeter working principle and its construction. The torque on the moving coil was proportional to the product of current and voltage, and therefore to the instantaneous power.
Electrodynamic wattmeter article about electrodynamic. This explains electrodynamometer type wattmeter construction and working principle of electrodynamometer type. Key item description 1 carry strap for carrying or hanging the instrument. Classification, absolute and secondary instruments, indicating instruments, control, balancing and damping, constructional details, characteristics, errors in measurement, ammeters, voltmeters. As shown in the above figure, the wattmeter has two sets of coils. Pdf on oct 1, 2016, slami saadi and others published. Download the pdf of this topic electrodynamometer type wattmeter. 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.
In electrodynamometer type wattmeter, moving coil works as pressure coil. The scale of the wattmeter illustrated in figure 2 is read directly only when the range switches are set to 1 a and 120 v. Thus circuit voltage is impressed across the pc and cc carries the circuit current. The scale of the electrodynamometer wattmeter is therefore uniform. It is based on the principle that mechanical force exists between two current carrying conductors. The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit.
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