The unit of electric power required to do work at the rate of one joule per second. Comparing rotations is therefore not an effective way to determine consumption. In this article, we attempt to understand the working. Implementation of a singlephase electronic watthour meter. Watt meter measures true rms watts this circuit will give you a good, accurate watt meter that can measure various power levels. The disc is placed between the air gap of the series and shunt electromagnet. The three main types are electrodynamic, electronic and digital. Operating principles, use, test, adjustment, maintenance general electric co. Magnetic principles and their relationship to current flow are examined to show what makes the meter disk spin.
It is the power expended when one ampere of direct current flows through a resistance of one ohm. A second terminal block between the current transformer and the meter simplifies service work. This will be converted into corresponding measurements in the display section. Symbol of power meter the traditional analog wattmeter is an electrodynamics instrument. They are typically calibrated in billing units, the most common one being the kilowatts hour, which is equal to the amount of energy used by a load of one kilowatt over a period of one hour, or 3,600,000 joules. Induction type watt hour meter or energy meter about circuit. This device is available in a purely electronic form too which is known as digital wattmeter. The ultraviolet lamps in the beds have a stated life, and a salon owner can more accurately tell when to change bulbs if an hour meter records when the lamp is on. Active power watts is comprised of the portion of the current which is in. The two fluxes have the same frequency but are displaced in time and space.
A calibration service for wattmeters and watthour meters. Ammeter definition and working principle electrical academia. In addition, many medical devices use hour meters to determine both service intervals as well as other. Watt hour meter, device that measures and records over time the electric power flowing through a circuit. Based on the flow of current, the ferriwheel rotates which makes rotation of other wheels. Mrevs mkh % meter accuracy srevs skh watt hour meter adjustments. Explanation of how kilowatt hour meters work electromechanical applied.
If one uses one kilowatt in onehour duration, one unit of energy gets consumed. A precise fraction of the current flowing in the circuit is diverted to operate the motor. Also around 1889, elihu thomson of the american general electric company developed a recording watt meter watthour meter based on an ironless commutator motor. Types of energy meters and their working principles. The focus meter was designed to be a lowcost, solidstate, kwhonly meter as an alternative metering and amr platform to the induction meter. The difference between watthour meter and var hour meter i understand, that the question is asking for the design and operation principle of the ferraris energy meter. Algorithms, electric energy measurement, electricity billing, microprocessors. The description can be hopefully found in profound electrical engineering textbooks, unfortunately i dont have a.
Energy meters are the basic part to measure the power consumption. What is the working principle of energy meters measure. For example, if you turn on a 100watt light bulb for 10 hours, the energy usage is calculated as 100 watts x 10 1,000 watts or 1 kilowatt hour. Electrical energy meters principles and applications energy management. The meter is provided with a field to which entries can be made for this purpose ct or vt factor. Bidirectional metering is available to customers who install renewable fuel generators such as solar, wind, hydro or biomass sources and operate the generator in parallel with their electric companys electrical system. Electrical energy meters principles and applications.
This device is made up from power, current and voltage transformers, who measure the average power. Implementation of a singlephase electronic watthour meter using. The torque is produced in induction relays due to the interaction of one alternating flux with eddy currents induced in the rotor by another alternating flux. Watt demand the usual demand billing factor where peak average demand is measured in watts or real power.
Meter dept general electric watthour meter 37 pages. This is the frequency of electricity, measured in hertz, of the power grid in the united states. The power consumed in a circuit is 1 watt if a potential difference of one volt causes 1 ampere of. Adjusting the meter is crucial if you want to get accurate readings from it. In principle, the watthour meter is a small motor whose instantaneous speed is proportional to the power passing through it. The basic unit of power is watts and it is measured by using a watt meter. This power is integrated over a time interval, which gives the energy utilized over. Taking into account the requirements of the meter, two. By implementing the watthour meter, we can know how much amount of electrical energy is used by a consumer or a residence or an electrically powered. For the purposes of maintenance of replacement or to catch unauthroized use. The phase displacement between the fluxes produced by the electromagnet is obtained by the flux generated by the two magnets having different resistance and inductance for the two circuits. Thus, 600 rkwh means that the disc must rotate 600 times for the meter to show consumption of one kilowatt hour. However, the material herein will provide sufficient information for testing. Single phase energy meter theory pdf download mastercard.
Your electric meter records electricity usage in kilowatthours. L and n correspond to the voltage inputs from the test setup. Once reactivated recycle power, the calibration led remains active for 24 hours. The meter platform will measure energy accurately over varying environmental conditions. Energy meters can vary in the number of rotations per kilowatt hour. These devices find their application in energy measurement and have the necessary architecture to support it. The conventional mechanical energy meter is based on the phenomenon of magnetic induction. Play now summary this 38minute video covers the operating principles and physical construction of electromechanical watthour meters. Voltmeter working principle if an ammeter is of dc type, then it has polarity signs on it for ensuring appropriate connection for an upscale indication.
The energy is the total power consumed and utilised by the load at a particular interval of time. Braking system the permanent magnet is used for reducing the rotation of the aluminium disc. The difference between watthour meter and varhour meter. However, the principle of watt consists of applying current and voltage to both a rotating standard meter and the meter under test, observing the revolutions of both and calculation accuracy by the following formula. Some meters measured only the length of time for which charge flowed, with no measurement of the magnitude of voltage or current. As shown in the above figure, the wattmeter has two sets of coils. The following directions should be followed when reading the dials of a watthour meter. An electrical power business uses electric meters to quantify the number of electricity consumed by each. If a meter is used in combination with a current transformer. The total revolutions in a given time are proportional to the total energy, or watt hours, consumed during that time.
Moreover, the working principle of a watthour meter is more or less similar to that of an induction type wattmeter. Work on the principle of conversion of electrical energy into mechanical work. Prepaymentprepaid energy meter introduction and working. The units of energy consumed are detected by the energy meter which shows the amount of power consumed in the form of the energy units. The watthour meter is often referred as energy meter or electric meter or electricity meter or electrical meter. The focus kwh has an infrared light emitting diode led that emits energy pulses.
Electrical power p is defined as the rate at which work is done in an electrical circuit. The energy meter has the aluminium disc whose rotation determines the power consumption of the load. Implementation of a singlephase electronic watt hour meter using the msp430f6736a if a test setup needs to be connected, the connections have to be made according to the evm design. Aug 10, 2010 electric meter, or watt hour meter, a device that measures the quantity of electric energy. It blinks when communication between dms2 and mimb16 normally works. Operating principles, use, test, adjustment, maintenance. Load limiting and emergency conservation modes set this meter apart when working in conjunction with a demand response program. A watt hour meter requires a power supply provided from the three phase network itself. You can read the meters output on its center display and reset it often to see how much electricity you are using over a specific period of time.
The description can be hopefully found in profound electrical engineering textbooks, unfortunately i dont have a reference at hand. Training sessions basic components 5 minutes identifies the basic compon. This is why the statement rotation per kilowatt hour is found on the meter. A calibration service for wattmeters and watthour meters gpo. A wattmeter does a complex job, measuring the power flowing through an electrical circuit. However, because most circuit breakers in homes are 15 amps, i made my unit to have a range of zero to 1500 watts. Energy meter or watthour meter is an electrical instrument that measures the amount of electrical energy. If one uses one kilowatt in one hour duration, one unit of energy gets consumed. The ac kilowatt hour meters used at present operate on the same principle as blathys original invention. Many of them use a small gear motor and an odometerlike set of digits. So energy meters measure the rapid voltage and curren. Types of energy meters and their working principles elprocus.
An electric watthour meter measures the electricity that the devices of your home or business use in watts per hour. Nov 29, 2014 the traditional form of wattmeter is called as dynamometer wattmeter. This meter overcame the disadvantages of the electrochemical type and could. The ampere hour meter or amp hr meter or ah meter is similar to the watt hour meter which is used to calculate the total usage of electricity at households and commercial establishments. This is equal to the total usage of electrical energy by a consumer of one kilowatt during a period of one hour and it is also equal to 3600000 joules. Digital electronic instruments measure many parameters and can be used where a wattmeter is needed. Electronic single phase watt hour meter adopts largescale ic, the latest microelectronic technologies and smt techniques.
Facilities instructions, standards, and techniques volume 310. The voltage coils numerous turns of wire already provide some phase shift the. The meter which is used for measuring the energy utilises by the electric load is known as the energy meter. As the interaction of alternating fluxes is the base of operation of induction relays, these are not used for the d. The kh of the meter is what is know as the watt hour constant. Implementation of a lowcost threephase watt hour meter using the msp430f67641 rev. Electric power, p, is defined as the rate at which electric energy, a work, is. The reading in kwh is obtained by multiply the number of rotations of the disc with the meter constant. Power consumed is shown by the energy meter in form of 1 unit or 1 kilo watt hour of energy consumed.
This power is integrated over a time interval, which gives the energy utilized over that time period. The calibration led is deactivated 24 hours after the meter powers up. The offered meter will count the number of cycles in vt output during each successive 15 minute block and divide the same by 900 when supply voltages are present to arrive at the average frequency the meter will also compute the reactive power on 3phase, 4wire principle, with an. Handbook on electricity meters asiapacific economic. An instrument which measures electrical energy in watt hours is essentially a wattmeter which accumulates or averages readings. The disc measured the power consumption in kilowatt hours. The following directions should be followed when reading the dials of a watt hour meter. The watthour meter works on the induction principle.
One kilowatt hour is the quantity of electric energy needed to supply 1,000 watts of electricity for a span of one hour. Oct 06, 20 i take apart an electromechanical power meter and describe how it uses magnetic fields to measure power consumed. It is used in domestic and industrial ac circuit for measuring the power consumption. Energy meter, meterk plugin lcd watt energy meter electricity energy monitor with 1224 hours mode and 2 modes 2 calculation method timed off timer 3. A calibration service for wattmeters and watthour meters author. The working principle of an electronic energy meter is a device that measures the electronic energy consumed usually in kwh. The units of energy consumed are detected by the energy meter which shows the amount of power consumed in form of the energy units. Watt hour meter structure this structure consists e shape electromagnet and a u shape electromagnet with a discfree to rotate in between them. Electricity meter integrated circuits and reference designs.
Pdf digital domestic meter for the measurement and billing of. The meter is based on reliable, field proven digital multiplication measurement technique. The difference between watt hour meter and var hour meter i understand, that the question is asking for the design and operation principle of the ferraris energy meter. Jun 30, 2018 working principle and construction of energy meter video lecture of measurement of capacitance chapter in subject electronic instrumentation and measurement for electrical, electronics, extc. A unit of energy, especially electrical energy, equ the work done by one watt acting for one hour and equivalent to 3,600 joules. The amount of power the meter can request is limited to the values imposed by regular standards 2 3, in the case of the meter developed the maximum power consumption from the grid is 2 w per phase. However, ampere hour meter takes into account the ampere hours and just like the watt hour meter, it is also an integrating meter. The calibration led is accessible from the front of the meter cover. It simultaneously measures the voltage and current values and multiplies them to give power in watts.
I take apart an electromechanical power meter and describe how it uses magnetic fields to measure power consumed. Light commercial kilowatt hour meter, 3phase, 120277 volt autoranging power supply suitable for both 277480v, 4w, wye and 240480v 4wire delta services, 7 jaw. So energy meters measure the rapid voltage and currents, calculate their product and give instantaneous power. It is often incased in glass and has a disk that rotates that. In the typical sense, the ampere hour meters are similar to the digital current meter, just like the odometers which are present in your automobile. 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. Although there are several different types of watt hour meters, each consists essentially of a small electric motor and a counter. Jul 25, 2018 energy meters are the basic part to measure the power consumption. How an electric meter reads power usage the spruce. Jul 25, 2018 watthour meter is in fact a measuring device which can evaluate and records the electrical power passing through a circuit in a certain time. We do not provide any control spring and pointer in an energy meter. In particular, conventional current flows into the positive terminal for an upscale meter deflection as shown in above figure. The following is a basic explanation of how bidirectional metering works.
The energy meter measures the energy consume by the electrical load. The dynamometer wattmeter works on the motor principle. Electric meter, or watt hour meter, a device that measures the quantity of electric energy. 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. It is used everywhere, no matter how big or small consumption it is.
Current carrying conductor place in a magnetic field experiences a torque. Here we discuss the construction and working principle of induction type energy meter. The solidstate types generally use a current transformer to measure the current produced in the currentcarrying conductors, which means. The power supply allows the operation of the energy meter powered directly from the mains. Implementation of a singlephase electronic watthour. 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.
Hour metes are designed to measure ontime, how long a piece of gear has been used. Study of single phase induction type energy meter or watthour meter. Watthour meter principles 1 instant video alexander. Constructionally an induction type single phase watt hour meter has many similarities to an induction type wattmeter. Whatever the criteria, the calibration system must have the ability to have. Robust revenuegrade watt hour and demand meters based on ges cutting edge technology providing typical 0. Power consumed is shown by the energy meter in the form of 1 unit or 1 kilo watt hour of energy consumed.