The ac line power meter is used to measure the power consumption of a equipment which is drawn from 115230v 5060hz power line. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power. Sep 16, 2016 as the name suggests the low power factor meter are the instruments that measures lower values of power factor accurately. Power factor meter operation archives instrumentation tools. The utility company charges you for the power you use based on the monthly readings of an electric meter that measures the current passing through the service entrance into your electrical service panel. A power factor meter is an electric instrument which is used to measure the power factor of various electrical machines like dc generator, ac motor, transformer etc and for measuring the power factor of various transmission and distribution lines of various electric power supplies. Electrodynamometer type instruments construction and. The basic unit of power is watts and it is measured by using a watt meter. Saturable core frequency meter construction working. To measure the real power or reactive power, a wattmeter designed to work properly with. Before we introduce various types of power factor meters it is very essential to understand what are the needs of power factor meter. Difference between electrodynamometer wattmeter and low power. The single phase dynamometer type power factor meter consists of one current coil and two voltage coils.
It is a measure of how effectively the current is being converted into useful work. Devices with coils or capacitors like pumps, fans and florescent light bulb ballastsreactive load have power factors less than one. Power factor meters electrodynamometer type power factor meter. Their intelligent adjustment interface ensures balanced usage of capacitors based on the number of switching operations and the connection time of each step, thus ensuring long life for switchgear and capacitors. Wattmeter is an instrument, used to measure power in a circuit using current and voltage of the circuit. In electrical engineering, the power factor of an ac electrical power system is defined as the. These load centers are controlled by distribution utilities, and there is an interchange of energy between different utilities connected to the grid. This meter is able to perform current, voltage and power measurements in three phase supply systems. The power factor of a resistive load like toaster or ordinary incandescent light bulb is 1 one. In power transmission system and distribution system we measure power factor at every station and electrical substation using these power factor meters. Working principle the basic working principle of pf meter is similar to that of dynamometer type wattmeter i.
How does a bidirectional electricity meter know import from export. The main principle of working of weston type frequency meter is that when an current flows through the two coils which are perpendicular to each other, due to these currents some magnetic fields will produce and thus the magnetic needle will deflects towards the stronger magnetic field showing the measurement of frequency on the meter. In order to simplify the problem, we assume that the current through coil b lags the voltage by exactly 90. Safety relay can be classified into electromagnetic safety relay, thermal reed relay and solidstate relay. They are used as watt meters,varmeters and with some modification as power factor meters and frequency meters. Ohms law states that voltage across a resistance is directly proportional to the current passing through it. May 15, 2018 before we introduce various types of power factor meters it is very essential to understand what are the needs of power factor meter. Power factor is the ratio between the kw and the kva drawn by an electrical load where the kw is the actual load power and the kva is the apparent load power. Induction type wattmeter or simply induction wattmeter belongs to the family of induction type measuring instrument. The power factor of transmission and the distribution lines is unity 1 leading because of the losses occurred in these lines and the reason of the losses is the length of the conductor or wire. The induced voltage is carried to the transmitter through the electrode circuit. Thepowerfactorofanalternatingcurrentflowingintoandoutof.
Power factor measurement provides us the knowledge of type of loads that we are using and helps in calculation of losses happening during the power transmission system and distribution. Sep 24, 2019 the single phase dynamometer type power factor meter consists of one current coil and two voltage coils. Induction type wattmeter construction working and torque. To describe the operating principle of a power factor meter is difficult without referring to a diagram, so i suggest. Voltmeter working principle, voltage sensitivity, types. Utility meters on the side of house measure this quantity real power and power company charge for it.
This video has described the construction and working of dynamometer type power factor meter. The current is in phase with the voltage when the load power factor is unity. Here, in the construction of this power factor meter, we divide the current coil into two equal parts. What is the working principle of energy meters measure. Automatic power factor correction electrical notes. Power factor meter principle s bharadwaj reddy august, 2018 a power factor meter is a type of electrodynamometer movement when it is made with two movable coils set at right angles to each other. How does a bidirectional electricity meter know import. Power factor meters electrodynamometer type power factor. It is a measure of how effectively the current is being converted into useful work output and more particularly is a good indicator of the effect of the load.
The power factor meter determines the types of load using on the line, and it also calculates the losses occur on it. Wattmeter is an instrument used to measure the electrical power. Nov 29, 2014 wattmeter is an instrument used to measure the electrical power. These power supplies may be from a grid stations, substations or from power houses. The induced voltage e is directly proportional to the velocity v of the fluid moving through the magnetic field b. Electrodynamic power factor meter single phase and three. The scale of the moving iron type extends over 360. Electric utilities use electric meters installed at customers premises for billing and monitoring purposes. The power factor is the cosine of the angle between the voltage and current. A singlephase meter is used in alternating current systems. For the energy or environment control purpose, a precise current, watt, power factor measurements are the first step, this application note is a guide to describe the theory of power meter and to choose the most suitable power meter from the. Before we introduce various types of power factor meters it is very. The individual pulses are then summated through the use of an electromechanical meter, and are made available at a pulse output as well.
Electrodynamometer type is more accurate than the moving iron type. The power consumed in a circuit is 1 watt if a potential difference of one volt causes 1 ampere of current to flow through the circuit. Circuit theory comparisons dc machines electrical drives electrical. Power factor meter connection, circuit, wiring diagram. This coil is split up into two parts and carries the current of the circuit under test. The wattimeter has a rotating conductive disk which is crossing two magnetic flux, one is produced by coil connected to ac supply voltage and the other by a coil connected to ac current, as they are ac some eddy or foucault currents are produced. You can take the real power shown by the meter and divide it by the va value to get the power factor. When the three phase power factor meter is connected in the circuit, under balanced load conditions, the angle through which the pointer is deflected from the unity power factor position is equal to the phase angle of. Electrical energy meters principles and applications. Power factor meters are mostly used for the observation of electric power to maintain the power factor for the balancing of voltage and current. Rather, the power equals the product of voltage and current, the apparent power, and a term called the power factor. Any basic meter has a potential difference across its terminals when a fullscale current flows through it. When connected to loads, they consume less power and start measuring instantaneous. To describe the operating principle of a power factor meter is difficult without referring to a diagram, so i suggest you do a search on the internet for this answer.
The traditional form of wattmeter is called as dynamometer wattmeter. The power factor of an unbalanced poly phase circuit is not uniquely defined. The dynamometer wattmeter works on the motor principle. Jun, 2019 single phase dynamometer type power factor meter. Since the induction phenomenon can only happen in the alternating current system, this instrument only measures ac power. Typical accuracies of a power meter wi ll be in the hundredths of a db, while other instruments i. Power factor meter working principle construction types. The power factor meter measures the power factor of a transmission system. How is the power factor part involved in wattmeter reading. There is a requirement of low power factor meter because, the usage of ordinary electrodynamometer wattmeter to measure power factor of a low pf load gives inaccurate results. Jun 08, 2019 before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type 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 mechanical force. How an electric meter reads power usage the spruce. When the power factor is less than 1, the current and voltage are out of phase. For that reason, an induction wattmeter differs from a dynamometer wattmeter.
What is the working principle of wattmeter and energy meter. The measurement of energy is accomplished by means of a voltagefrequency converter connected downstream from the power meter. Power factor can also be calculated by installing watt meter along with the ampere meter and volt meter by using the power factor basic formula. Electronic measurement power factor meter slideshare. An electric meter or energy meter is a device that measures the amount of electrical energy supplied to or produced by a residence, business or machine. As the name suggests the low power factor meter are the instruments that measures lower values of power factor accurately. Why we do not directly calculate power factor in an ac circuit just by dividing the power with product of current and voltage because these readings can. So again, this meter doesnt directly deal with power factor. The power factor meter determines the types of load using on the line and it. Trivector meter is an energy meter which accurately measures all the parameters of supply such as voltage, current, power factor, active load, reactive load, apparent load etc. Inductors explained the basics how inductors work working principle duration. By checking this box, i agree to receive marketing communications and product offers by email from fluke electronics corporation, transacting under fluke industrial, or.
Import and export of electrical energy secure meters. Pressure coil is connected across the circuit whose power is to be measured and current coil is connected in series. Mar 25, 2015 to describe the operating principle of a power factor meter is difficult without referring to a diagram, so i suggest you do a search on the internet for this answer. Circuit diagram, working principle and its applications. According to the measuring mechanism, it can be divided into three categories. It measures real power going back to first principles and whether the voltage and current signals are sines or not. Power measurement in a threephase system using wattmeter. Electronic energy meters are accurate, precise and reliable type of measuring instruments when compared to electromechanical induction type meters. What is the working principle of a power factor meter. When the three phase power factor meter is connected in the circuit, under balanced load conditions, the angle through which the pointer is deflected from the unity power factor position is equal to the phase angle of the circuit, because the two moving coils are fixed 120 apart. Electric components of a utility distribution system are designed on a kva basis. An electricity meter, electric meter, electrical meter, or energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device. Nov 05, 2017 working principle of electrodynamometer wattmeter electrodynamometer wattmeter consists of two coils, pressure coil pc and current coil cc.
The power factor meter is also called the phase meter. Before we study the internal construction of electrodynamometer type wattmeter, it is essential to know the working principle of electrodynamometer type wattmeter. Sep 02, 2014 30 power capacitors power factor correction on site with pole cap 31. A second terminal block between the current transformer and the meter simplifies service work. So, electronic type of threephase energy meter is explained below with its working principle. Working principle of indicating instrument about circuit. Figure 14 3 f power factor meter schematic ground detector the ground detector is an instrument which is used to detect conductor insulation resistance to ground. Mar 23, 2018 construction table of contents1 construction2 working principle3 comparison with the moving iron power factor meter the construction of a single phase electrodynamometer power factor meter is shown in fig.
Electrical energy meters principles and applications energy management. The q meter operates on the principle of series resonance i. The basics how capacitors work working principle duration. Errors in single phase dynamometer type power factor meter. According to the measured phase number, there are single phase and three phase. The laws and relationships for delivering power were originally developed for direct current. The other differences between wattmeter and energy meter are represented below in the comparison chart. We have an idea of the working principle of e lectrodynamometer. The meter requires large working force as compared to the electrodynamometer type meter.
The basic working principle of power factor meter is similar to that of dynamometer type wattmeter i. I turn car compressor into working engine duration. Voltmeter working principle, voltage sensitivity, types and. Working principle of power saver as per manufacture. The bulk of cost savings power factor correction can offer is in the form of avoided utility charges for low power factor. The wattmeter is an instrument for measuring the electric power or the supply rate of electrical energy in watts of any given circuit. Difference between electrodynamometer wattmeter and low.
Single phase dynamometer type power factor meter about circuit. Under the alternating current effect, the electromagnetic coils mounted on the measuring tube will make two parallel measuring tubes vibrating at a certain fixed frequency. In electrodynamometer power factor meter working forces are very small as compared to moving iron type. As we have just told, one of the conditions of the construction of dynamometer type single phase power factor meter is. It consists of a fixed coil which acts as the current coil. A series of blog posts about how changes in culture and technology are reshaping what managers do. The qmeter operates on the principle of series resonance i.
Single phase dynamometer type power factor meter about. Single phase electrodynamometer power factor meter. The working principle of safety relays can also be roughly divided into three types. Often one does not know the power factor of an ac circuit and cannot determine the power from separate voltage and current measurements. If one uses one kilowatt in onehour duration, one unit of energy gets consumed. A power factor meter is a type of electrodynamometer movement when it is made with two movable coils set at right angles to each other. Electrical power p is defined as the rate at which work is done in an electrical circuit. The power factor of a balanced polyphase circuit is the same as that of any phase.
The two stationary coils, s and s1, are connected in series in. Power factor controller or power factor correction delete. Yet, the electrodynamic wattmeter allows one to determine directly the power in an ac circuit. So, if the supply frequency changes, this condition will not continue as the same. A direct reading power factor meter can be made with a moving coil meter of the electrodynamic type, carrying two perpendicular coils on the moving part of the instrument. Power factor meter working principle your electrical guide. This device is available in a purely electronic form too which is known as digital wattmeter. If the applied voltage across the circuit is keptconstant then voltmeter connected across the capacitor can be calibrated to indicate quality factor value directly. Single phase electrodynamometer power factor meter youtube. Electrodynamometer type wattmeter ammeter working principle and. Types of energy meters and their working principles elprocus.
Mechanical resonance frequency meter vibrating reed ratiometer type. Because dynamometer type wattmeter can measure both ac and dc power. The meter can either be a mechanical analog meter that is read monthly by a utility service person who visits your home, or a newer digital meter that may send information via internet or radio. An ohm meter, or a series of lights, can be used to detect the insulation strength of an ungrounded distribution system. The method of connection of this type of power factor meter, in a 3f circuit, is shown in figure 14. Import and export of electrical energy introduction power flow electricity is generated by generating stations and transmitted to load centers from where it is distributed to end consumers. The flow principle behind magnetic flow meters is known as faradays law, mathematically defined as ekbdv. Sep 23, 2018 the power factor meter is also called the phase meter. A power factor meter is a type of electrodynamometer movement when it is made with two movable coils set at. The significant difference between the wattmeter and the energy meter is that the wattmeter measures the electrical power flows in the circuit, whereas the energy meter measures the total electrical energy consumes by the electrical load. 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.