A Six Months Training Project onCALIBRATION & TESTING OF ELECTRONIC METERS

Company Profile:Punjab State Power Corporation Limited (PSPCL)Punjab State Power Corporation Limited (PSPCL) is the electricity generating company of the Government of Punjab state in India. Punjab State Electricity Board (PSEB) was a statutory body formed on 1-2-1959 under the Electricity Supply Act.1948. Subsequently with the re-organization of the erstwhile State of Punjab under the Punjab Re-organization Act 1966 this form came into existence w.e.f. 1st May, 1967. PSPCL was incorporated as company on 16-04-2010 and was given the responsibility of operating and maintenance of State's own generating projects. The business of Generation of power of erstwhile PSEB was transferred to PSPCL. Govt. of Punjab unbundled Punjab State Electricity Board into two companies: Punjab State Power Corporation Ltd. (POWERCOM) Punjab State Transmission Corporation Ltd. (TRANSCO)

PSPCL

TypeGovernment-owned Corporation-PSU

IndustryElectricity Distribution

Founded2010 (vide notification number1/9/08-FB(PR)196 Dt. 16.04.2010)

ProductsElectricity

Websitehttp://pspcl.in/

Punjab State Electricity Board is the utility for one of the essential services for general public because power supply is the basic need of each and every household. Economy as well as growth of the State is primarily dependent on Power. For making the public aware of about the various activities being undertaken by the PSEB to ensure availability of an efficient and reliable power supply system, information which are commonly required by the general public as per the provisions of the Right to Information Act-2005, are being made available on the PSEB Web-Site for which PSEB is bringing out this handbook. This is helpful in bringing transparency in the working of PSEB and also provisions under "Right to Information Act-2005" shall be complied with.All the power Stations operated at their best ever plant load factor since their installation. Net Power generated during 2008-09 is 37222 Million units, which is more than 2006-07 by 2238 Million Units resulting of 6.40% increase in two years. The 1980 MW (3x660) Talwandi Sabo Power Project awarded to M/s Sterlite Energy Ltd. Mumbai on 4.7.08 and PPA signed on 1.9.08. Power purchase agreement with M/S GVK for installing 2x270 MW thermal power station at Goindwal Sahib signed on 26 May 2009.The foundation stone has been laid and the company has started the construction. Second stage of Lehra Mohabbat Thermal Power Station for 2x250 MW has been commissioned. Its Unit-III achieved CoD on 16.10.08 and Unit-IV synchronized on 2.8.08 on coal. 4.76 lakh new connections including 61849 No. tubewell connections were released during 2007-09. 24 Hrs. Urban pattern supply made available to 12428 villages and 6158 Deras/ Dhanies with 5 or more houses. To help SC & BPL consumers, free monthly consumption up to 200 units allowed for connected load of 1000 watts w.e.f. 12-10-06 instead of earlier 500 watts. Strict measures have been taken to reduce power theft. Disciplinary action taken against the erring employees and 5 numbers Anti Power Theft Police Stations have been set up. New technologies like electronic meters, remote control of transformers, remote meter reading and HVDS system for AP/ Industries introduced. 20.29 lakh meters out of 55.98 lakh General/ Industrial Consumers shifted out of their premises as on 31.3.09 to curb theft of energy. All these measures have helped in reducing losses by 4% from 23.92% (200607) to 19.91% (200809) / which resulted in substantial increase in revenue. During 2007-09, 62 numbers New Grid substations erected and capacity at 132 number Grid substations augmented besides addition of 1070 circuit km. Transmission line and 149 MVAR shunt capacitors to State Grid.PSPCL procures power from various sources other than own thermal units, central generating stations ,energy banking arrangements and short term power purchases through traders to bridge the gap between demand and supply during paddy season from June to October.The audit report has observed that the actual average rate of power purchase during 2010-11 from other sources is Rs. 5.15 per unit against commissions approved rate of Rs. 3.12 per unit. In this year short term power purchase to power purchase under spot purchase including over drawls from grid was estimated as 60:40 but actually it turned out to be 73:27.This ratio for 2011-12 was 96:4 against projection of 80:20.PSPCL has been purchasing expensive power from natural gas and liquid fuel based stations for all these years where average variable cost exceeded Rs. 8 per unit. The option of purchasing power through exchanges would have been better option.

TABLE OF CONTENTS:Electricity Meters.. 6History of Electricity Meters..... 8Types of Electricity Meters. 12Meter Testing and Calibration Regulations. 19What is Calibration.. 22Why is Calibration so important. 23Calibration process.. 24Metering Equipment (M.E) Laboratory, Ladhewali... 27NABL Accreditation Certificate. 28Testing Bench.. 29Steps Involved for Operating 1-Phase Test Benches.. 43Steps Involved for Operating 3-Phase Test Benches.. 44Procedure to Calibrate and Test Meters on the Bench 45Some Tests that are conducted on Meters... 47Features of Meters and its Modes... 49Meter Tampering and Security 52Tamper Tests conducted on Meter.. 53Data Downloading from Meter to the Computer 55Data Downloading from Meter to CMRI 56Data Downloading from CMRI to the Computer 56What is CMRI. 57Procedures to get your Meter Tested... 58Problems Faced... 60Solutions Suggested 61Summary. 62References... 63Electricity MetersAn electricity meter or energy meter is a device that measures the amount of electric energy consumed by a residence, business, or an electrically powered device.Electricity meters are typically calibrated in billing units, the most common one being the kilowatt hour [kWh]. Periodic readings of electricity meters establish billing cycles and energy used during a cycle.Electric Meter, or Watt-hour Meter, an instrument that measures the amount of electric energy used by a consumer. The meter is calibrated in kilowatt-hours. One kilowatt-hour is the amount of electric energy required to provide 1,000 watts of power for a period of one hour. (Ten 100-watt light bulbs left on for one hour consume one kilowatt-hour of electric energy.)In settings when energy savings during certain periods are desired, meters may measure demand, the maximum use of power in some interval. "Time of day" metering allows electric rates to be changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for demand response load shedding during peak load periods.

An electric power company uses electric meters to measure the amount of electricity consumed by each of its customers. The power company installs an electric meter near where its power lines enter a customer's building. It reads the meter periodically and charges the customer for the amount of electricity used.The most common type of electric meter is essentially an electric induction motor that drives a series of geared wheels connected to indicators on the meter's face. This type of meter is designed for use with alternating current. It contains two electromagnets and a metal disk that is free to rotate between them. One electromagnet is powered directly by current from the incoming power lines; the other, by current drawn through the building's electrical circuits. The interaction of the magnetic fields produced by the coils causes the disk to rotate. Two permanent magnets near the disk's edge brake the disk in such a way that the speed of rotation is proportional to the amount of current drawn. As the disk rotates, it turns the series of geared wheels connected to the indicators on the meter's face.Electronic watt-hour meters use solid state circuits that produce electrical signals whose frequency or strength is proportional to the voltage and current being used. These signals are converted into energy measurements recorded by mechanical or electronic indicators. Electronic watt-hour meters are generally more expensive than electromechanical models, but are more accurate. They can provide such features as the ability to record separately the energy consumed during different times of day and the ability to report meter readings by means of signals sent through the power lines to the power company.

History of Electricity MetersMost of us have paid the electric bill at one point or another (some less frequently and/or punctually than others), but its likely few of us have ever stopped and wondered who it was that designed the electric meter mounted to the side of our house. We just go about our daily lives without ever considering such a thing, despite the annoyance of getting a monthly electric bill in the mail. The truth is, however, that without such a design and device, power companies would have no way to regulate and monitor the amount of electricity consumed by each household.As such, before the invention of the electric meter, power companies had no way to monitor or price the power they supplied to individual households and businesses. And before there were power companies, individual households were responsible for producing their own power. Imagine today if every house was connected to a water wheel, giant windmill, or noisy generator rather than most having a convenient little box counting off every kilowatt-hour consumed. Most people, unless they live by a stream that can turn a water wheel, would opt for the little box and monthly bill.So, who do we owe credit to for the modern day design of the electric meter that so unassumingly adds up our periodic power usage? His name is Oliver B. Shallenberger, and his invention enabled so many of us to be connected to the grid and charged accordingly. But to understand Mr. Shallenbergers great contribution and how we have come to be so dependent on electricity, it is helpful to first understand the evolution of this power source. Most people are familiar with the story of Benjamin Franklin tying a key to a kite and discovering electricity when it was struck by lightning. This colourful interpretation of certain events has been skewed from real facts by Americans through its telling and retelling, generation to generation. The truth is people have known about electricity, or at least had some understanding of it, since the Ancient Egyptians. It remained no more than an intellectual curiosity, however, until the late nineteenth century.It was around this time that a great debate was going on between two famous physicists. Known as the War of the Currents, this battle was between Thomas Edison and George Westinghouse over the idea of DC versus AC power for commercial American use. (AC or alternating current is current that flows with a constantly changing magnitude, or goes from positive to negative repeatedly. DC or direct current describes current that is at a constant value with no phase. SPOILER ALERT: Modern American homes and businesses have outlets that supply 120V 60Hz AC power.)The main reason for this debate was that Edison was the first to design numerous DC-oriented technological advancements, and DC power was the standard in the U.S. In the late 1880s, however, Nikola Tesla came up with the ideas for transformers and other electronic circuits, and AC became much more practical for residential consumption. George Westinghouse bought the rights to Teslas polyphase system patents along with other transformer designs and formed Westinghouse Electric & Manufacturing Co. in 1886. Once Westinghouse had the rights and support from Tesla himself, he was able to commercialize the production of AC power in the U.S.It was around this time that Westinghouse hired an ex-naval officer eager to pursue his interest in electricity. This man was O.B. Shallenberger. And by 1888, Shallenberger had become Westinghouses chief electrician.Though its less popular than Ben Franklins key and kite legend, the invention of Shallenbergers meter is a story equally apocryphal. The story goes that while Shallenberger and an assistant were working on an AC arc lamp, a spring fell and came to rest on the inside ledge of the lamp. As the assistant went to reach for it, Shallenberger stopped him when he realized the spring had rotated. Shallenberger eventually discovered that the changing electric fields induced a magnetic field which caused the metal spring to rotate. With this at the heart of his idea, Shallenberger designed an AC ampere-hour meter three weeks later. His design implemented the use of an induction-based motor which comes from coiling a number of current carrying wires together that inherently possess a magnetic field through the beautiful relationship know as electromagnetism.Using the original figure from the patent Shallenberger received for his design, (B) is the coil of wires that carry the current the resident is using. This current produces a magnetic field which points in the direction through the wires (e and e). This force acts upon the metal disc or armature (A), causing it to rotate. This rotation spins the metal rod (a) the disc is connected to causing a registering worm (h), which is like a screw, to rotate as well. The rotation of this worm turns a worm-gear or wheel, which is connected to a registering train that is calibrated to display the amount of electricity used. The registering train is like a bunch of dials that point to numbers that represent the amount of current used. Also connected to the rod are four fan blades (N), which are used to slow down and eventually stop the disc from spinning once the force is removed (i.e. once the current stops flowing). The systems were calibrated by using a known amount of power and then using a little algebra and testing to determine coefficients, which took the fans retarding force into effect along with friction in the bearings between the disc and mounting rod, and in the gears.Overall the design was simple yet ingenious and very effective in doing what it needed to do, so much in fact that the same design is still used in most meters today albeit with some modern day improvements. Shallenberger himself was responsible for many improvements and reinventions of his first AC electric meter and received a number of patents because of it. The reason the design was and still is so effective is because it consumes very little power assuring that customers only pay for the power they are using, while still being very accurate in recording power consumption. Modern day electric meters now use better materials for the armature and rod, along with better casings and registering components to minimize external defects.

According to the 1903 textbook Electrical Engineering: Measuring Instruments for Commercial and Laboratory Use, It has already been pointed out that the great trouble in the generality of motor meters is the friction of the moving parts, which, if not minimized and compensated for, causes irregularities in the direct proportion between speed and the thing measured. Shallenbergers design uses the induced magnetic field from the current to measure the amount of current used which consumes little to no power. The textbook goes on to say, Consequently it is an advantage that there should be no rubbing contacts in the meter, other than, of course, in the bearing, which can be minimized, but not entirely eliminated. Shallenberger also did this by using gears, turned by the disc and rod, which had very little friction. A meter madethat fulfils the above requirements in a highly satisfactory degree is that introduced by Mr Shallenberger some years ago, and which may be said to be one of the most satisfactory coulomb-motor meters in existence at the present day. (Meters intended to measure electric quantity are called coulomb meters) These statements of praise still hold true just as they did over a hundred years ago.

Once electric companies had an effective way to monitor the power consumption of individual households and businesses, the Second Industrial Revolution ensued as rural areas received electricity. Since then, electricity has become an absolute necessity for modern day living. Every appliance and luxury electronic in a typical household runs on electricity provided by the local power company, and will continue to do so for quite some time.Through the development of other technologies like computers and highly sophisticated communication systems, electric meters have begun to evolve into more technologically advanced systems as well. Concepts such as Smart Grids and AMRs (automatic meter readings) have become integrated with the electromechanical electricity meters that are based on Shallenbergers original design. These newer technologies eliminate the need for the meter man to get the reading from the meter itself. Essentially the registering system in the original design has gone from analog to digital and can now send readings to huge databases for billing, analysis, and troubleshooting. Smart Grids even take it a step further and can actually give real-time readings from anywhere as well as statistically determine how much power individual households will use allowing for more efficient power consumption.They say the greatest ideas are those that stand the test of time. O.B Shallenbergers design of an induction motor-based electricity meter is still used in most meters today. The simple yet effective design has been able to monitor and register power consumption of individual households and businesses for over a century. Despite our shared dislike of paying the electric bill, if no one has complained enough to make it change, we must be getting a fair deal after all.Types of Electricity Meters:Electricity meters operate by continuously measuring the instantaneous voltage (volts) and current (amperes) to give energy used (in joules, kilowatt-hours etc.). Meters for smaller services (such as small residential customers) can be connected directly in-line between source and customer. For larger loads, more than about 200 ampere of load, current transformers are used, so that the meter can be located other than in line with the service conductors. The meters fall into two basic categories, electromechanical and electronic.1. Electromechanical MetersThe most common type of electricity meter is the electromechanical induction watt-hour meter.The electromechanical induction meter operates by counting the revolutions of a non-magnetic, but electrically conductive, metal disc which is made to rotate at a speed proportional to the power passing through the meter. The number of revolutions is thus proportional to the energy usage. The voltage coil consumes a small and relatively constant amount of power, typically around 2 watts which is not registered on the meter. The current coil similarly consumes a small amount of power in proportion to the square of the current flowing through it, typically up to a couple of watts at full load, which is registered on the meter.The disc is acted upon by two sets of coils, which form, in effect, a two phase induction motor. One coil is connected in such a way that it produces a magnetic flux in proportion to the voltage and the other produces a magnetic flux in proportion to the current. The field of the voltage coil is delayed by 90 degrees, due to the coil's inductive nature, and calibrated using a lag coil. This produces eddy currents in the disc and the effect is such that a force is exerted on the disc in proportion to the product of the instantaneous current, voltage and phase angle (power factor) between them. A permanent magnet exerts an opposing force proportional to the speed of rotation of the disc. The equilibrium between these two opposing forces results in the disc rotating at a speed proportional to the power or rate of energy usage. The disc drives a register mechanism which counts revolutions, much like the odometer in a car, in order to render a measurement of the total energy used.The type of meter described above is used on a single-phase AC supply. Different phase configurations use additional voltage and current coils.The disc is supported by a spindle which has a worm gear which drives the register. The register is a series of dials which record the amount of energy used. The dials may be of the cyclometer type, an odometer-like display that is easy to read where for each dial a single digit is shown through a window in the face of the meter, or of the pointer type where a pointer indicates each digit. With the dial pointer type, adjacent pointers generally rotate in opposite directions due to the gearing mechanism.The amount of energy represented by one revolution of the disc is denoted by the symbol Kh which is given in units of watt-hours per revolution. The value 7.2 is commonly seen. Using the value of Kh one can determine their power consumption at any given time by timing the disc with a stopwatch.

P = {{3600 \cdot Kh } \over t}.Where:t = time in seconds taken by the disc to complete one revolution,P = power in watts.For example, if Kh = 7.2 as above, and one revolution took place in 14.4 seconds, the power is 1800 watts. This method can be used to determine the power consumption of household devices by switching them on one by one.Most domestic electricity meters must be read manually, whether by a representative of the power company or by the customer. Where the customer reads the meter, the reading may be supplied to the power company by telephone, post or over the internet. The electricity company will normally require a visit by a company representative at least annually in order to verify customer-supplied readings and to make a basic safety check of the meter.In an induction type meter, creep is a phenomenon that can adversely affect accuracy that occurs when the meter disc rotates continuously with potential applied and the load terminals open circuited. A test for error due to creep is called a creep test.Two standards govern meter accuracy, ANSI C12.20 for North America and IEC 62053.

2. Electronic MetersThe conventional mechanical energy meter is based on the phenomenon of Magnetic Induction. It has a rotating aluminium Wheel called Ferriwheel and many toothed wheels. Based on the flow of current, the Ferriwheel rotates which makes rotation of other wheels. This will be converted into corresponding measurements in the display section. Since many mechanical parts are involved, mechanical defects and breakdown are common. More over chances of manipulation and current theft will be higher.

Electronic meters display the energy used on an LCD or LED display, and some can also transmit readings to remote places. In addition to measuring energy used, electronic meters can also record other parameters of the load and supply such as instantaneous and maximum rate of usage demands, voltages, power factor and reactive power used etc. They can also support time-of-day billing, for example, recording the amount of energy used during on-peak and off-peak hours. The meter has a power supply, a metering engine, a processing and communication engine (i.e. a microcontroller), and other add-on modules such as RTC, LCD display, communication ports/modules and so on. Electronic Energy Meter is based on Digital Micro Technology (DMT) and uses no moving parts. So the EEM is known as Static Energy Meter In EEM the accurate functioning is controlled by a specially designed IC called ASIC (Application Specified Integrated Circuit). ASIC is constructed only for specific applications using Embedded System Technology. In addition to ASIC, analogue circuits, Voltage transformer, Current transformer etc. are also present in EEM to Sample current and voltage. The Input Data (Voltage) is compared with a programmed Reference Data (Voltage) and finally a Voltage Rate will be given to the output. This output is then converted into Digital Data by the AD Converters (Analogue- Digital converter) present in the ASIC. The Digital Data is then converted into an Average Value. Average Value / Mean Value is the measuring unit of power. The output of ASIC is available as Pulses indicated by the LED (Light Emitting Diode) placed on the front panel of EEM. These pulses are equal to Average Kilo Watt Hour (kWh / unit). Different ASIC with various kWh are used in different makes of EEMs. But usually 800 to 3600 pulses / kWh generating ASIC s are used in EEMs. The output of ASIC is sufficient to drive a Stepper Motor to give display through the rotation of digits embossed wheels. The output pulses are indicated through LED. The ASIC are manufactured by Analogue Device Company. ADE 7757 IC is generally used in many countries to make EEMs. ADE 7555 / 7755 ASIC maintains the international standard CLASS I IEC 687/ 1036. Due to innovation in this field, Smart meters have been introduced. A smart meter is usually an electronic device that records consumption of electric energy in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing purposes. At PSPCL, the electronic meters used are mostly manufactured by Larsen & Toubro Limited, Flash Electronics, etc. which makes both single as well as three phase meters for domestic use.

Solid State DesignThe metering engine is given the voltage and current inputs and has a voltage reference, samplers and quantisers followed by an ADC section to yield the digitised equivalents of all the inputs. These inputs are then processed using a digital signal processor to calculate the various metering parameters such as powers, energies etc.The largest source of long-term errors in the meter is drift in the preamp, followed by the precision of the voltage reference. Both of these vary with temperature as well, and vary wildly because most meters are outdoors. Characterising and compensating for these is a major part of meter design.The processing and communication section has the responsibility of calculating the various derived quantities from the digital values generated by the metering engine. This also has the responsibility of communication using various protocols and interface with other add on modules connected as slaves to it.RTC and other add-on modules are attached as slaves to the processing and communication section for various input/output functions. On a modern meter most if not all of this will be implemented inside the microprocessor, such as the real time clock (RTC), LCD controller, temperature sensor, memory and analog to digital converters.

3. Smart MetersA smart meter is usually an electronic device that records consumption of electric energy in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing purposes. Smart meters enable two-way communication between the meter and the central system. Unlike home energy monitors, smart meters can gather data for remote reporting. Such an advanced metering infrastructure (AMI) differs from traditional automatic meter reading (AMR) in that it enables two-way communications with the meter.

The term Smart meter often refers to an electricity meter, but it also may mean a device measuring natural gas or water consumption.Similar meters, usually referred to as interval or time-of-use meters, have existed for years, but "Smart Meters" usually involve real-time or near real-time sensors, power outage notification, and power quality monitoring. These additional features are more than simple automated meter reading (AMR). They are similar in many respects to Advanced Metering Infrastructure (AMI) meters. Interval and time-of-use meters historically have been installed to measure commercial and industrial customers, but may not have automatic reading.Research by Which?, the UK consumer group, showed that as many as one in three confuse smart meters with energy monitors, also known as in-home display monitors. The roll-out of smart meters is one strategy for energy savings. While energy suppliers in the UK could save around 300 million a year from their introduction, consumer benefits will depend on people actively changing their energy use. For example, time of use tariffs offering lower rates at off-peak times, and selling electricity back to the grid, may also benefit consumers.The installed base of smart meters in Europe at the end of 2008 was about 39 million units, according to analyst firm Berg Insight. Globally, Pike Research found that smart meter shipments were 17.4 million units for the first quarter of 2011. Visiongain has determined that the value of the global smart meter market will reach $7bn in 2012.Smart meters may be part of a smart grid, but alone, they do not constitute a smart grid.Since the inception of electricity deregulation and market-driven pricing throughout the world, utilities have been looking for a means to match consumption with generation. Traditional electrical and gas meters only measure total consumption, and so provide no information of when the energy was consumed at each metered site (market use rates are readily available to utilities however). Smart meters provide a way of measuring this site-specific information, allowing price setting agencies to introduce different prices for consumption based on the time of day and the season. Smart meters may include measurements of surge voltages and harmonic distortion, allowing diagnosis of power quality problems.Utility companies propose that from a consumer perspective, smart metering offers potential benefits to householders. These include, a) an end to estimated bills, which are a major source of complaints for many customers b) a tool to help consumers better manage their energy use - stating that smart meters with a display outside their homes could provide up-to-date information on gas and electricity consumption and in doing so help people to manage their energy use and reduce their energy bills and carbon emissions. Electricity pricing usually peaks at certain predictable times of the day and the season. In particular, if generation is constrained, prices can rise if power from other jurisdictions or more costly generation is brought online. Proponents assert that billing customers by time-of-day will encourage consumers to adjust their consumption habits to be more responsive to market prices and assert further, that regulatory and market design agencies hope these "price signals" could delay the construction of additional generation or at least the purchase of energy from higher priced sources, thereby controlling the steady and rapid increase of electricity prices.[citation needed] There are some concerns, however, that low income and vulnerable consumers may not benefit from intraday time-of-use tariffs.

Meter Testing and Calibration RegulationsQuality, reliability and customer service have become a major focus in the industry, and central and several state electricity regulators have been appointed and have started functioning. Some of the regulators have been established under the Electricity Regulatory Commission Act 1998, and will now be deemed to have been set up under the Electricity Act 2003. The Central Electricity Regulatory Commission (CERC) is mainly responsible for regulating tariffs for generation, inter-state transmission of energy including tariffs, advising the government on tariff policy, and promoting competition, efficiency and economy in the electricity industry.An electricity meter or a watt-hour meter measures the electrical energy passing through the meter and may be single-phase or poly-phase. The calibration assures that the measurement errors can be kept within the desired limits. By the regular calibration at SP the stability of the meter can be monitored closely. The normal calibration method is to generate the desired power levels, and to compare the measured energy of the unit under test with the power measured by a reference system, usually by comparing the frequency of pulse outputs. The application may be one-phase or poly-phase and for low or high power factors. The frequency is normally 50 Hz but may be varied from 16.7 Hz to 400 Hz.The Indian government has launched a Mission 2012 Power for all campaign, liberalised policies to improve the power sector, introduced reforms and energy conservation, and through its Accelerated Power Development and Reforms Programme (APDRP) has laid emphasis on distribution sector efficiency improvement. There are 28 states and 7 union territories in India, and the Indian constitution stipulates that both central and state governments are responsible for electricity and should play major roles.With the enactment of the Indian Electricity Act 2003 on 2 June 2003, restructuring of the power sector leading to privatisation and unbundling of the erstwhile State Electricity Boards (SEBs) into corporates has begun. Nine SEBs have already been unbundled/ corporatized, and distribution in Orissa state and Delhi (union territory) has been privatised. A few old private distribution companies remain in some cities, like AEC in Ahmedabad, SEC in Surat, and CESC in Kolkata.Eighteen SERCs Orissa, Andhra Pradesh, Uttar Pradesh, Maharashtra, Gujarat, Haryana, Karnataka, Rajasthan, Delhi, Madhya Pradesh, Himachal Pradesh, West Bengal, Punjab, Tamil Nadu, Assam, Uttaranchal, Jharkhand and Kerala have issued tariff orders. Many have also issued a code for supply and distribution, as well as grid codes, metering code, code for open access and so on.Most utilities operate their own meter test laboratories, which are generally equipped with transformer operated manual or semi-automatic test benches and some portable test instruments. The majority of this equipment comes from local manufacturers. Many laboratories still use old Rotary Sub standards, although a few utilities have modernised in recent times by the introduction of modern automatic test benches and electronic portable test/calibration instruments. The importance of accreditation to NABL has not, however, been fully recognised and only two or three meter test labs belonging to private utilities are working towards this accreditation. These labs need significant improvement in test equipment, operating conditions, training of staff and overall quality management to boost consumer confidence, and it is a cause for concern that very little is being done to address this.Instrument transformers (CT and PT), though an important part of a metering system, are rarely tested after installation. Many utilities have some kind of test facilities, but are generally inadequately equipped in terms of either equipment or the manpower and systems to conduct these tests.Utilities routinely use their own internal meter test labs for inward inspection of electricity meters. However, as part of their buying process some utilities have started to use the services of either their own meter test/calibration labs or external accredited labs for the independent assessment of the quality of sample batches of meters. A subset of type tests is then conducted either before purchase decisions are made or on delivery of the meters. This is certainly a good move, and will help utilities ensure that the meters they have ordered meet quality requirements. Most utilities, however, still prefer to use the services of government labs only. This needs to change utilities need to recognise and develop confidence in the value of NABL accreditation and give equal opportunity to other labs too.The Central Electricity Authority (CEA) has been designated as an agency for formulating national electricity policy; it advises government on technical matters and specifies grid standards and conditions for the installation and operation of meters. Under the Electricity Act 2003, 100% metering and installation of meters for energy accounting and audit has been made mandatory. (At present about 13 % of customers are not metered, in particular in the agricultural sector). The Act envisaged that 100% metering would be achieved within two years, but it is likely to take another two or three years to reach total coverage. Meanwhile rationalisation of tariffs to reduce and eliminate cross-subsidies has also been emphasised.Indian laws which came into effect in February 2003 require that every electricity meter needs to be approved and certified by the Bureau of Indian Standards (BIS) and marked with the BIS logo. BIS is responsible for specifying Indian national standards and granting type approval (product certification) based on the type test reports issued by accredited test laboratories. The Bureau also provides licences to manufacturers based on its approval of their manufacturing processes, which allow them to self-certify and mark the BIS logo on every meter they produce. All over the world, large-scale replacements of installed base kWh-meters are taking place in smart metering projects. In most of these locations, the majority of the installed meters are electromechanical meters, with proven long standing technology. Financial risks are huge, as replacements are undertaken in large-scale accelerated projects, rather than over longer-term, life-cycle substitutions. Utilities require certainty on the expected lifetime of new meters and are requiring meter manufacturers to independently test and certify the reliability of these meters. For this purpose, a number of standards have been developed.In the past the Indian Electricity Rules 1956, under section 57, specified the requirements for testing and acceptance limits for the meters installed at customer premises. The requirements regarding periodicity of testing, however, were left to state governments. As a result, in practice very few meters were periodically tested, except for those of very large power consumers or in the event of disputes or complaints.Now the CEA has issued a draft for the installation and operation of meters which covers various types and applications such as grid meters, availability based tariff (ABT) meters between grid companies and state electricity boards/state transmission companies, substation and feeder energy accounting meters, industrial, commercial and domestic meters. This document also specifies the broad technical specifications and requirements for periodic testing of various types of meter and associated instrument transformers in other words, the full metering system. It recommends testing of meters in situ in substations for system power equal to or above 10 MW every six months, and for loads less than 10 MVA every two years. Meters for consumers with loads of 20 kVA up to 100 kVA should be tested every year; loads above 100 kVA every three, six or twelve months depending on load category; and domestic meters every five years. In addition all instrument transformers must be tested every five years. Many state regulators have incorporated or are likely to incorporate these requirements in their documents, such as code of supply, grid codes and metering codes.The National Electricity Policy formulated by the CEA has called for the establishment of third party meter testing facilities by SERCs. Some SERCs have started discussions on how to implement this, but it will take a year or two before something concrete emerges out of this guideline. The Indian Electricity Grid Code draft document released recently has specified special static energy meters (frequency based metering) for use on all interconnection points on the grid.

What is Calibration?Calibration is defined as an association between measurements one of a scale or accuracy made or set with one piece of equipment and another measurement made in as similar a way as possible with a second piece of equipment. The piece of equipment or device with the known or assigned accuracy is called the standard.Standards vary from country to country depending upon the type of industry whilst manufacturers designate their measurement criterion and recommend the frequency and level of calibration, depending upon industry requirements, how often the device is used and the specific application.Some companies will offer a pre-calibration test where they test equipment first, to determine whether it is suitable for calibration, whilst others will submit all equipment for calibration whether or not it is working properly.In general use, calibration is often regarded as including the process of adjusting the output or indication on a measurement instrument to agree with value of the applied standard, within a specified accuracy however this is actually two processes: calibration and adjustment. It is important therefore to understand exactly what service you require.It is also important to understand what is being calibrated and how the calibration is being performed. As an example, consider a digital thermometer that uses an external temperature probe. Many companies are surprised to learn that their calibration is performed using a simulated temperature value that is applied to the thermometer only. Here, a test instrument is attached to the digital thermometer and a voltage equivalent to a specific temperature is applied to the digital thermometer. The result is then recorded and the thermometer considered to be calibrated.Many users require, and probably expect, a more rigorous calibration to be performed that reflects real world usage. Here, the preferred method is to test both the digital thermometer and the temperature probe together (In other words a system test) and to use a real heat source. The value displayed by the system being tested is then compared against the standard (The system with a known or assigned accuracy from the first paragraph!).

Why is Calibration So Important?Calibration defines the accuracy and quality of measurements recorded using a piece of equipment. Over time there is a tendency for results and accuracy to drift particularly when using particular technologies or measuring particular parameters such as temperature and humidity. To be confident in the results being measured there is an ongoing need to service and maintain the calibration of equipment throughout its lifetime for reliable, accurate and repeatable measurements.The goal of calibration is to minimise any measurement uncertainty by ensuring the accuracy of test equipment. Calibration quantifies and controls errors or uncertainties within measurement processes to an acceptable level.So if you know that a particular food product needs to be kept above 68C and the instrument system you are using displays a figure of 68.8C then provided the system is calibrated to be accurate within 0.5C at 68C you can be confident the food is safe, if the system has an accuracy of 1C though then you cannot be certain that the foods temperature has been correctly controlled. Food is, of course, only one example of why it is essential to have a confirmed calibrated level of accuracy. Manufacturing processes that require specific controlled curing temperatures are another in fact the list goes on.In summary, calibration is vitally important wherever measurements are important, it enables users and businesses to have confidence in the results that they monitor record and subsequently control.

Calibration ProcessCalibrations are typically performed by using a reference measurement technique. A known amount of energy is simultaneously supplied to a reference meter and to the unit under test (UUT). A reading from the reference meter is then compared to a reading from the UUT and the error is calculated. Three separate pieces of calibration equipment are typically required to complete this task. 1. An energy supply (a power supply) 2. A reference energy meter 3. A device for counting pulses from both the reference meter and the UUT, which then compares the two counts and generates an error indication. The block diagram of the calibration setup is shown in Figure 1.

In this setup, the 6100A is used simply as the energy supply (current supply and volt- age supply), and without the use of any other functions available with the 6100As energy option. However, the 6100A energy option does enable the user to perform the calibration with- out the necessity of using the energy reference meter and/or the pulse comparator, thereby effectively replacing the functionality of both instruments.Calibration of instruments that measure energy is no different than any other calibration. The instrument under test is sup- plied with a known quantity of the parameter being calibrated, and the instrument is interrogated in order to ascertain the value of the parameter that it has measured. This value is then compared with the quantity supplied, and the measurement error is calculated. Electricity meters, almost without exception, use a technique of generating pulses to indicate the amount of energy they have measured. Each pulse represents a specific number of watt-hours (or VA hours, VAR hours etc.). These pulses are transmitted from the meter in a number of different ways.1. On older meters, energy is recorded by counting the number of passes of a black mark on the surface of a spinning metal disc. 2. By a flashing LED 3. As a direct electrical output (Typically TTL) 4. Some of todays newer meters will even include highly advanced reporting mechanisms such as Ethernet or Bluetooth interfaces. Because meters are used to measure a wide range of energy, from watt-hours to Gigawatt- hours, the pulses generated can represent different amounts of energy. This amount of energy is specified by the meter manufacturer, and is known as the meter constant (sometimes referred to as k).For example, a specific meter may generate 100 pulses for every kilowatt-hour measured; another may generate the same number of pulses per megawatt- hour measured. Whatever the criteria, the calibration system must have the ability to have this number set within its system in order that it can calculate the correct quantity of energy from the pulse count.Replacing the reference meter with a 6100A The energy reference meter serves two main purposes. Firstly, it is used to provide a reliable source of traceability, and secondly, to measure the amount of energy actually delivered. The 6100As ability to measure or calculate time, means that it already knows how much energy it has delivered with a high degree of accuracy. The function of the reference meter, therefore, becomes redundant. In this type of setup, the comparator is still used, but with the 6100A now generating the pulses, instead of the reference meter. To mimic the K value of the meter under test, it is possible to program the 6100A to generate a specific number of pulses, per unit of energy delivered. This calibration setup is shown in Figure 2.

The 6100As energy user interface can be accessed via the waveform menu. Note: If accessed directly from power- up, then the Esc key on the keyboard must be pressed first. Here, a soft key labelled Energy Counting can be found. Upon selecting this key, the user must then configure the 6100A according to his test setup. This can be done by selecting the soft key Configure Meter Constants, which in turn accesses the Channel Configuration and Meter Constants screen The first panel, MUT Source, determines which sockets on the front panel of the 6100A are being used as energy pulse inputs. A number of different configurations can be set up in this panel, from one to six single phase meters, or even a single pulse three phase meter (The Sum of Channel 1,2 and 3 check box). Having identified the pulse source channel(s), the user must then select the reference source. This will depend upon which circuit (as shown in Figures 2, 3 and 4) the user has chosen to perform the tests. If the 6100As internal reference is being used, as shown in Figure 4, the check box Main Output must be selected. Alternatively, if either an external single phase or three phase meter is utilized as a reference, then one of five other check boxes must be selected, according to the test setup being used. Two such examples are shown in Figures 1 and 3. The Meter Constant Base drop-down menu allows users to select any one of three meter base units, depending upon the meter being testedWh (Real power), VAh (Apparent power or VARh (Reactive power). Having selected this, the meter constants must then be specified. This must be done for both the meter under test, the external energy reference meter (if used) and finally, the reference pulse output of the 6100A. For both the Meter Constant (MUT) and Meter Constant (Reference) panels, this will be entered according to the output specifications of the meter under test and external energy reference meter (if used). In the case of the Meter Constant (Output) panel, a value can be set which specifies the effective meter constant of the Pulse Out connector. Whenever an energy test is active, this output is a pulse stream representing the total power and energy of the active V/I outputs of all 6100A/ 6101As in the system. There are also internal user selectable pull-up resistors for pulse inputs. This is particularly useful for meters with open col- lector outputs. A separate pullup resistor is associated with each meter constant. For the meter under test and reference meter, these can be selected as either 150 W or 1 kW. Similarly, a user selectable internal pull-up is provided for the main outputs energy pulse output. This can be selected or deselected using the Use Internal pull-up check box.

Metering Equipment (M.E) Laboratory, Ladhewali Metering Equipment Laboratory established at Ladhewali, Jalandhar is a state-of-the-art testing and calibration laboratory accredited by NABL (National Accreditation Board for Testing and Calibration). All the new electronic meters that are to be sanctioned by the PSPCL are calibrated and tested here before sending them into regulation. All the new meters that have been recently received from the manufacturers are tested and if a meter fails the tests, it is send back to the manufacturers for replacement. There are two 3-phase 4-wire benches present for testing of three phase meters. There is also one bench for 1-phase meters. Testing of challenged meters is also done at this laboratory. PSPCL acts as a supervisory coordinator for this meter quality control, working in cooperation with meter manufacturers. In particular, we carry out random spot checks on domestic kWh meters, assessments of challenged meters, and statistical quality checks on heat meters.Random testing Random tests provide a cost-effective and practical way to monitor the quality of the overall installed base of domestic meters. For these tests, we select a small sample of meters at random. They then compare their readings with calibrated equipment on-site, analyse the results and issue a supervisor-judged report.Challenged meters Challenged meter testing aims to resolve disagreements between consumers and utility companies. By providing an independent test, we can demonstrate the accuracy of the energy usage being registered by a particular kWh meter.

NABL Accreditation CertificateNational Accreditation Board for Testing and Calibration Laboratories (NABL) is an autonomous body under the aegis of Department of Science & Technology, Government of India, and is registered under the Societies Act 1860. NABL has been established with the objective to provide Government, Industry Associations and Industry in general with a scheme for third-party assessment of the quality and technical competence of testing and calibration laboratories. Government of India has authorised NABL as the accreditation body for Testing and Calibration Laboratories.In order to achieve this objective, NABL provides laboratory accreditation services to laboratories that are performing tests / calibrations in accordance with ISO/IEC 17025:2005 and ISO 15189:2007 for medical laboratories. These services are offered in a non-discriminatory manner and are accessible to all testing and calibration laboratories in India and abroad, regardless of their ownership, legal status, size and degree of independence.NABL accreditation system complies with ISO/IEC 17011:2004 and Asia Pacific Laboratory Accreditation Cooperation (APLAC) MR001. Based on evaluation of NABL operations by APLAC in 2000, NABL has been granted signatory member status by APLAC and International Laboratory Accreditation Cooperation (ILAC) under their Mutual Recognition Arrangements (MRAs). Under these MRAs, the reports issued by NABL accredited laboratories are considered to be equivalent to reports issued by laboratories accredited by (currently) 76 accreditation bodies in 64 economies. NABL has undergone re-evaluation by four member APLAC evaluation team in July 2008. APLAC/ILAC has recommended NABLs Mutual Recognition Arrangement (MRA) status for further four years with extension of scope for Medical Testing laboratory as per new international standard ISO 15189:2007.Recently, NABL also added a new dimension in the area of accreditation as a new program on "Accreditation of PT Providers" based on international standard ISO/IEC 17043 Conformity Assessment- General Requirements of Proficiency Testing and strive to obtain ILAC / APLAC Mutual Recognition Arrangement (MRA) Signatory Status for international acceptability also.The users have access to information regarding accredited laboratories through web-based directory of NABL accredited laboratories.NABL website is updated continuously with respect to status of accredited laboratories and their scope of accreditation. The list of laboratories which are either suspended or their scope of accreditation is partially or fully withdrawn is also available for the benefit of the users. The laboratories will be able to acquire the necessary NABL documents through the website thereby eliminating postal delays. Suggestions are welcome from users of the website for further improvement.

Testing BenchesWe will now discuss the various meter testing equipment that are used on a daily basis to test and calibrate the meters in detail.

The laboratory has both single-phase and three-phase testing benches. There are 2 three phase benches with 10 meter slots. There is 1 three phase meter testing bench which has 3 slots. There is 1 single-phase meter testing bench which has 10 slots for meter testing. This testing bench is 13 feet in length, 2 feet in width and 8 feet in height. This bench was build by a German manufacturer named by Zera and was procured by PSPCL, last year. The bench accords with the standard of IEC 60736:1982 testing equipment for electrical energy meters, IEC 62053. The bench can be used to test three phase active energy meter and reactive energy meter (up to 0.1 class), it is also suitable for four quadrant energy meter testing. The bench can do warm up test, starting test, no load test(creep test), error test(accuracy test), dial test, tests of the influence quantities(reverse phase, voltage unbalance, harmonic wave and so on) and test of repeatability of the measurements. The bench is using the PWM to amplify voltage/current output, the high efficiency at >85%, and lower the heat. The PWM can check the malfunction checking, preset, alarm, and protection. The signal source is using the newest digital controlled sine wave technology for frequency, amplitude and phase adjust. The signal source can repeatedly add 2-21 harmonics on the first sine wave, or cause sub-harmonic wave and odd sub-harmonic wave. The bench is using the HY 5303C-22 reference standard energy meter with comparison technology to offer the accuracy of energy meters. The bench is using the error processor system to calculate the error of each energy meter by the sub-error system, which can be connected by the internal RS485. The same specification but different constant energy meter can be tested at one time. The test bench can be installed scanning head, it can offer 3 ranges adjustment. It is also can be accepted the signal for both round-style energy meter and digital LED energy meter. The test bench has the auto-search black marker function which can precisely locate the black marker during the no load test and starting test. The bench can choose to operate by keyboard or PC which is very convenient. The working status of bench can be seen very clear and easy operation. The bench is using the testing software complied with WINDOWS98/2000/XP/7 which can auto-testing different energy meters. The software can realize the data from energy meter for statistics, search and management. The energy meter hanging rack is made by Aluminum compound. The whole device configuration is a reasonable design and nice outfit.Specifications of 3-Phase Testing Bench (Zera)Incoming Voltage: 3X230V/400V +/- 10%........65HzOutgoing Voltage: 30 to 300V ; 300VAOutgoing Current: 0.0012 to 120A / 300VAMaximum Voltage: 300VMaximum Current: 120A

Specifications of 1-Phase Testing Bench (EMH)Incoming Voltage: 3X230V/400V +/- 10%........65HzOutgoing Voltage: 30 to 300VOutgoing Current: 0.0012 to 120A / 1200VAMaximum Voltage: 300VMaximum Current: 120A

Parts of Testing bench discussed briefly below:-

1. Scanner (SH-11)

The SH 11 model scanning head was especially de- signed both for scanning of the marks on the rotating discs of mechanical meters or simulated disc marks on LCD displays and for detection of light emitting diodes (LEDs) of electronic meters. The choice of operation with mechanical or electronic meters is made by simple rotation of a selection switch. The precision optical lens is designed to make the scanning head insensible to external light. Its compact, robust construction makes the head equally suitable for use in stationary test consoles as well as for use with mobile and portable equipment. The impulse output of the scanning head delivers a positive output pulse of the duration 0.5 ms. Light Emitting Diode (LED) impulse detection with electronic meters The duration of optical impulse signals from electric meters may be detected and evaluated by use of the SH 11 head. The LED signal from the meter under test must fulfil the following conditions: 1. The impulse length must be 100 s and the impulse pause must be 600 s 2. The changeover from dark to light state must take place in 20 s and the change from light to dark be 100 s 3. Short impulses or impulses with a 1:1 ratio (with- out modulation or with an 8 kHz modulated switch-on time) and with a frequency of up to 800 Hz may be scanned 4. The wavelength of the received signal must lie within the range of 500 - 950 nm

User Controls

2. Leads

The above image represents the 3-phase meter testing bench wires. In the 3-phase testing bench, a single meter reserves 4 wires to work. In the above image for 3 phases, 3 wires for current flow and 1 wire for earthing. The 1st wire is for 1st phase incoming (Red) and 2nd wire is for 1st phase outgoing (Red). The 3rd wire is for 2nd phase incoming (Yellow) and 4th wire is for 2nd phase outgoing (Yellow). The 5th wire is for 3rd phase incoming (Blue) and 6th wire is for 3rd outgoing (Blue). The last wire is the earthing wire and is to be attached to the neutral slot. There are 3 slots for incoming current phases whose origin point is from the left of the bench. There are 3 slots for outgoing current phases so as to continue the current flow and keep the circuit intact. The neutral slot is reserved for earthing wire so as to ground the circuit in case of overflow. In 1-phase meter testing bench, a single meter reserves 2 wires to work. Basically, a single phase meter has 4 slots where the connections can be made. The 1st wire is for the incoming current and 2nd wire is for the outgoing current. The first two slots are to be used for this purpose. The last 2 slots are for neutral wires in which one earth wire is to be attached. As mentioned before, the incoming current brings the current from the bench to the meter whereas; the outgoing is to continue the current flow and to keep the circuit intact.

3. Reference

Calibration of instruments that measure energy is no different than any other calibration. The instrument under test is sup- plied with a known quantity of the parameter being calibrated, and the instrument is interrogated in order to ascertain the value of the parameter that it has measured. This value is then compared with the quantity supplied, and the measurement error is calculated. Electricity meters, almost without exception, use a technique of generating pulses to indicate the amount of energy they have measured. Each pulse represents a specific number of watt-hours (or VA hours, VAR hours etc.). These pulses are transmitted from the meter in a number of different ways.

The energy reference meter serves two main purposes. Firstly, it is used to provide a reliable source of traceability, and secondly, to measure the amount of energy actually delivered. The IS-1s ability to measure or calculate time, means that it already knows how much energy it has delivered with a high degree of accuracy. The function of the reference meter, therefore, becomes redundant. In this type of setup, the comparator is still used, but with the IS-1 now generating the pulses, instead of the reference meter. To mimic the K value of the meter under test, it is possible to program the IS-1 to generate a specific number of pulses, per unit of energy delivered.4. Batteries

The testing benches are given power and voltage from these batteries. At PSPCL, there are 24 batteries in place for the two 3-phase meter testing benches. These batteries are responsible for maintaining constant voltage and current supply across the test benches. In the second lab where the 1-phase testing bench is present, there are batteries which are responsible for the supply of constant voltage and current to the bench. These batteries provide the amount of voltage that is summoned upon by the lab expert who decides what amount of current a meter can withstand. Imax is the current the meter can withstand and Ib is the basic current that flows through a meter.

5. Emergency Measures

When you are working with live wires containing alternating current, safety precautions must be taken. The emergency measures are to be done in order to ensure the safety of the laboratory employees. A light signals are attached on top of the bench which signifies whether the bench is working or not. The light signals shows whether the current is running through the bench or not. The Red light in the lamp signals that the bench is working or is ON. It means the current is flowing through the bench right now as voltage has been applied across the bench. The Green light in the lamp signals that the bench is not working or is OFF. It means that no current is flowing through the bench as there is no voltage applied across the bench. The Blue light signals emergency button has been pressed. It means that there is a problem with the bench and the wires to the bench need to be removed from the main lines.

Emergency button is provided on the meter testing bench. Its a big red button placed on the both sides of the bench. Pressing this button immediately cuts off the power to the bench. Thus, preventing any leakage of the current which would otherwise, cause a fatal accident. When you are working with live wires containing alternating current, safety precautions must be taken. The emergency measures are to be done in order to ensure the safety of the laboratory employees. Whenever there is any kind of an emergency, the employees are requested to press this red button so, as to cut off any power to the bench. Pressing the button will also light up the blue light on the lamp attached to the bench.

6. Software UsedCAMCAL for WINDOWS is a comprehensive software package designed to fulfil the current requirements of the modern meter testing environment but also provides the flexibility to easily incorporate future meter testing requirements. CAMCAL for WINDOWS software allows the control of both static and portable meter test equipment, including the recording and evaluation of meter and measurement data. CAMCAL for WINDOWS software can be used throughout the meter test environment. Tests can be carried out for simple or highly complex meters in accordance with the customers requirements and national / international test and calibration regulations.

CAMCAL for WINDOWS software combines the various functional modules required in modern meter test systems, with a common and consistent user interface. The modular system allows control of various hardware units with a common software platform. Functions for laboratory or on-site measurement are provided together with the ability to test highly complex modern meters with integral tariff devices. The user interface of the basic version shows all the essential information required, therefore making the system easily understandable to operators with limited technical knowledge. Automatic meter testing Automatic meter tests are executed in three steps: 1. The user defines meter type descriptions and test sequences 2. The test is executed and the results are stored in the database 3. The results can be presented in a simple test results form, or be post-processed for presentation in form of a report. Additional options include automatic generation of files for importing into customers metering/asset database for instance.Meter type description The meter type description contains the electrical and functional definitions of meters under test (connection values, constants, registers, etc.). For the tariff device communication, a communication module is assigned to the meter types. This defines the data to be selected or programmed plus the dispatching commands, adaptable by the customer, makes the fully automatic examination of high-functional meters and tariff devices possible. The basic version supports the communication protocol in accordance with that described in the IEC 62056-21 Mode C standard. As an additional option the communication protocol is prepared according to dlms / COSEM. Test sequence A test sequence describes the order and content of the various test steps in a sequence. For each test step the desired test quantities (current, voltage, phase angle, frequency, etc.) are specified. In addition to the respective test method (e.g. error measurement, register tests, etc.) each checkpoint can be linked with control commands. Control commands display for instance instructions to the operator, switching of tariff relays or dispatching of commands e.g. to adjust time Meter testing The user allocates to each active measurement position a meter type and selects a test sequence. Subsequently the user will comfortably be guided through the test. The actual status of the test and active test point is clearly indicated at all times. It is possible to display simultaneously the actual test values and/or results in their own windows using large, easily visible fonts. MTE is able to provide customer specified modules which can be integrated into the standard software for fully automatic calibration of modern meters. MTE also supports the integration of alternative communication protocols for tariff devices.Results After executing an automatic test sequence all saved results are available for further data processing, such as creating an individual test report or export to Excel tables. The results can also be viewed and evaluated directly using several sort criteria in the database. The CAMCAL Report Generator enables the user to create and define their own protocol masks (calibration certificates, pass/fail reports, Statistical reports, customer reports, etc.). Furthermore the CAMCAL Report Generator has the flexibility to add to reports logos, diagrams and fields (e.g. for signatures) etc.

Additional standard functions of the CAMCAL for Windows SoftwareTesting of modern meters requires an adaptable and flexible software package. Because of its modular design, CAMCAL for Windows is able to provide this requirement. CAMCAL for Windows Software meets the following requirements: Modular extensions of semi-automatic and fully automatic systems are possible without extensive software adaptations Demonstration programmes allow training to be given before delivery of the test system Standardized meter type and test sequence definitions considerably reduce the need for extensive training and familiarisation Data export modules support data transfer to other systems The operator interface is available in many different languages Password protection is provided for different user levels Import and export functions enable the easy transfer of meter types, test sequences, report protocol masks etc. between test systems or across sites or between manufacturers and customers for instance.

Steps Involved for Operating 1-Phase Test Benches

1. Switch on the main MCB mounted on the wall.

2. Switch on the MCB of CVT meant for giving supply to the test bench and computer.

3. Switch on the supply to the UPS and press the button on the UPS to turn it on.

4. Switch on the computer.

5. Switch on the MCB provided on the reference source and press the green button to start the test bench. Both LEDs on the source should glow now and also green signal should light up on the test bench.

6. Check the connections of all the meters on the test bench. Potential leads must be out of their sockets for the meter portion on which no meters have been connected.

7. Select CAMCAL icon on desktop.

8. Open the software and start the testing as per the meters connected and test results required.

Steps Involved for Operating 3-Phase Test Benches

1. Switch on the main MCB mounted on the wall.

2. Switch on the MCB of CVT meant for giving supply to the test bench and computer.

3. Switch on the supply to the UPS and press the button on the UPS to turn it on.

4. Switch on the computer.

5. Switch on the MCB provided on the reference source and press the green button to start the test bench. Both LEDs on the source should glow now and also green signal should light up on the test bench.

6. Check the connections of all the meters mounted on the bench. In case of whole current meters, the position on which no meters have been connected, their Current Transforms must be short-circuited; also potential leads must be out.

7. Select CAMCAL icon on desktop.

8. Open the software and start the testing as per the meters connected and test results required.

Procedure to Calibrate and Test Meters on the Bench

1. Mount the meters that are to be tested onto the hooks present on the bench slots. Connect all the wires according to the positions.

2. Now, align the impulse LED on the meter with the SH-11 impulse scanner. By using the LED on the scanner, you can align them together which will lead to correct reading of the impulse of the meter. The initial readings on all the meters are noted down on a notebook alongside its serial number in the slot-wise order.

3. Turn on the bench as instructed and turn on the computer. On the desktop, click on CAMCAL software which has been installed in the computer as the compatible software to the bench.

4. On double-clicking the CAMCAL icon on desktop, a new window will open.

5. On this new window, click on the Element tab.

6. A drop-down menu appears. Place your mouse on the New, which will lead to another drop-down menu. Click on Test Run.

7. A new window will appear. In this window, there are 5 different tabs. In the first tab Common Properties, you could put in the Test name, Temperature and Humidity in the lab. at that point, the Supervisor name, etc.

8. On moving to second tab Test Devices on the window, we can here, add the meter by filling its properties. Depending upon the bench type, there will be a list of installed meters compatible to that bench. We can select from the list the type of meters in Meter name. The Manufacturing Number, Owners Number, Contract Number, Year of Manufacturing and Certification Number are noted from the meter and are put into the software. The meters are added one by one. We fill out these sections and then, click on Add. After adding all the meters that have been mounted on the bench, we go to the next tab.

9. In the third tab Sequence of Test procedures, there is a list of pre-installed tests that can be run on the meter are mentioned. According to the type of calibration and testing that is being done on the meter, the test is chosen. After choosing the test type, click on Add and that test will be sequenced.

10. Click on the fourth tab Test Run, all the specifications of the meter and of the test you want to run are enlisted, we can check every parameter and then, after confirming, click on Start.

11. When you click on the Start button on the window, power will be given to the bench. The lamp attached to the bench will now be signalling Red, meaning that the bench is working.

12. We can watch the progress of the test being run on the window. The % errors present in all the meter readings are shown alongside their slots. The time remaining for the test to be completed is also shown.

13. The last test that is done on meters is a Dial Test. It is also known as a Counter Test. In this test, the readings on the meter that are currently, after running for some time, being shown by the meter is noted and is filled in this new window. All the readings are noted from the meters in the slot wise order and are filled alongside the serial number of the meters.

14. When the test is completed, we go to the next tab Results. It gives us the specific details about the meter and the % error that is present in the meters reading. The data can be exported by clicking on the Export button which will export the data to MS Excel. Now, the results have been exported to the MS Excel. The data can be analysed properly and a report can be prepared. The print option is present to get a hard copy.

Some Tests that are conducted on Meters 1. Scanner Test: In this test, the scanners check whether they are able to read the impulses of the meter or not. If the %age error is greater than 1%, the scanner head must be aligned properly to the meter.

2. 100% Imax UPF: This test can be done on both single and three phase meters. In this test, the meter is given 100% maximum current that the bench can withstand. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

3. 100% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 100% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

4. 75% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 75% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

5. 50% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 75% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

6. 25% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 25% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

7. 10% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 10% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

8. 5% Ibasic UPF: This test can be done on both single and three phase meters. In this test, the meter is given 5% basic current that flows through the bench. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

9. 100% Ibasic 0.5 lag: This test can be done only on three phase meters. In this type of test, the three phases of Red, Yellow, and Blue are shifted by an angle of cos 60 generating a lag in between these three phases. The meter is given 100% basic current with 0.5 lag in between the phases. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

10. 100% Ibasic 0.8 lead: This test can be done only on three phase meters. In this type of test, the three phases of Red, Yellow, and Blue are shifted by an angle of sin 60 generating a lead in between these three phases. The meter is given 100% basic current with 0.8 lead in between the phases. The impulses of the meter are then, noted by the scanner and then, it runs those noted impulses with the reference. By comparing with the reference, it gives us the %age error in the functioning of the meter.

11. Dial Test: This test can be done only on three phase meters. This test is conducted in the very end of the test run. Initial readings have been inserted in the beginning. The final readings are noted down by the supervisor and are filled into the software. These readings are taken into account and are compared with the reference. Based on the results of reference, the error calculation is done.

Features of Meters and its ModesAll the meters, that are generally tested and calibrated for public distribution, have 8 energy registers. The meters can measure Active, Reactive and Apparent energies in all four quadrants. 8 Energy Accumulators are usually available in KWh, KVarh (lag and lead), and KVah in forward and reverse direction.All the meters have keys on their panels which makes it easy to scroll through the various parameters. These keys are also useful to perform manual reset. Rugged polycarbonate casing makes these meters a good insulator, hence, no need of external earthing terminal. EEPROM backup is used to store meter data, ensures data safety in power failures. Retention period is 10 years in case of power failures. RTC with battery backup is used for time keeping. It has a calendar of 100 years. Meter can be reset in 4 ways:1. Manual Reset2. Auto monthly & Manual Reset3. Auto monthly4. CMRI resetLast 12 reset backup data provided for 8 energies, MD, Avg. PF for both tariff and non-tariff wise along with Date and Time stamp of reset. Reset count is provided which indicates no. of resets performed. Tariff registers defines the register to be updated depending on the time of the day and maximum of 8 tariff registers can be selected.Load survey records are contained by the 18 registers with 8 Energies Phase wise voltages & currents, Avg. voltage, Avg. current, Avg. power factor and Load survey snapshot. These records store selected energies consumed for the programmed integration period and total number of days.The meter keeps a record of the number of times tampering has been done. Tampers like voltage & current failure, voltage & current unbalance, current reversal, current bypass, current open, low power factor, magnetic interference, over voltage, over lead, abnormal frequency and top cover open can be recorded with default persistence time of 5 minutes for occurrence and 2 minutes for restoration. The persistence time can also be customer specific. All PSPCL subscribers have a persistence time of 30 minutes. The meter calculates the instantaneous Power Factor of the system. The meter also calculates the instantaneous active, reactive and apparent powers irrespective of the configuration of the meters.Communication from the meter is done via a optically isolation serial interface port conforming to the IEC 61107 standards available. RS232/RS485 communication ports are generally provided only on requests.The parameters calculated by the meter are displayed on the custom built LCD. Display parameters can be selected from any of 339 parameters, 339 to 350 are extra customer specific parameters. The sequence of display is selectable. The scroll rate of the display parameters is programmable from 3 to 60 seconds. Three display modes are available.Display Mode 1: Display parameters selectable upto 55 numbers in any sequence required. Auto and manual scroll facility is available. Mode 1 generally displays readings of Active Energies.Display Mode 2:Display parameters are selectable upto 255 numbers in any sequence required. Manual scroll facility is available. Mode 2 generally displays readings of Reactive Energies.Display Mode 3:Display parameters are fixed. High resolution cumulative forward & reverse KWh/KVArh/KVAh.., available in 2+6 format, i.e. xx.xxxxxx. Manual scroll facility is available.

Connection Indicative Diagram

Tampering and SecurityAn electric meter is a device used for measuring the amount of electrical energy supplied to a residential or commercial building. Due to the increasing cost of electricity, tampering and security in electric meters has become a major concern for government agencies across the globe. Especially in populous countries like India and China tampering in electric meter and energy theft have become quite common. Electric meters can be manipulated, thus causing them to stop, under-register or even bypassing the meter. Consumers, who are tamper with electric meter, effectively use power without paying for it. This theft or fraud can be dangerous as well as dishonest. Electric meter security is looked upon as major issue in many countries today.Meters can be manipulated to make them under-register, effectively allowing power use without paying for it. This theft or fraud can be dangerous as well as dishonest.Power companies often install remote-reporting meters specifically to enable remote detection of tampering, and specifically to discover energy theft. The change to smart power meters is useful to stop energy theft.When tampering is detected, the normal tactic, legal in most areas of the USA, is to switch the subscriber to a "tampering" tariff charged at the meter's maximum designed current. At US$ 0.095/kWh, a standard residential 50A meter causes a legally collectible charge of about US$ 5,000.00 per month. Meter readers are trained to spot signs of tampering, and with crude mechanical meters, the maximum rate may be charged each billing period until the tamper is removed, or the service is disconnected.A common method of tampering on mechanical disk meters is to attach magnets to the outside of the meter. Strong magnets saturate the magnetic fields in the meter so that the motor portion of a mechanical meter does not operate. Lower power magnets can add to the drag resistance of the internal disk resistance magnets. Magnets can also saturate current transformers or power-supply transformers in electronic meters, though countermeasures are common. These magnets prevent the alternating current from forming eddy currents in the rotor, by saturating the coils or current transformers.Rectified DC loads causes mechanical but not electronic meters to under-register. As the DC currents do not cause the coils to make eddy currents in the disk, thus causing reduced rotation and a lower bill. Other ways of tampering in electric meters and playing with the electric meter security is to use some combinations of capacitive and inductive load, which also result in reduced or reverse motion.All of these effects can be detected by the electric company, and many modern meters can detect or compensate for them. The owner of the meter normally secures the meter against tampering. Revenue meters' mechanisms and connections are sealed. Meters may also measure VAR-hours (the reflected load), neutral and DC currents (elevated by most electrical tampering), ambient magnetic fields, etc. Even simple mechanical meters can have mechanical flags that are dropped by magnetic tampering or large DC currents.Newer computerised meters usually have counter-measures against tampering. AMR (Automated Meter Reading) meters often have sensors that can report opening of the meter cover, magnetic anomalies, extra clock setting, glued buttons, inverted installation, reversed or switched phases etc.Some tampers bypass the meter, wholly or in part. Safe tampers of this type normally increase the neutral current at the meter. Most split-phase residential meters in the United States are unable to detect neutral currents. However, modern tamper-resistant meters can detect and bill it at standard rates. Disconnecting a meter's neutral connector is unsafe because shorts can then pass through people or equipment rather than a metallic ground to the generator or earth.Aphantom loopconnection via an earth ground is often much higher resistance than the metallic neutral connector. Even if an earth ground is safe, metering at the substation can alert the operator to tampering. Substations, inter-ties, and transformers normally have a high-accuracy meter for the area served. Power companies normally investigate discrepancies between the total billed and the total generated, in order to find and fix power distribution problems. These investigations are an effective method to discover tampering.Today, many power companies are installing remote-reporting meters which are capable of detect any tampering in electric meters, and discover energy theft. These smart power meters are particularly helpful in preventing energy theft and encouraging security in electric meters.A large portion of a countrys revenue is lost due to the high density of tampering and security in electric meters. Hence it becomes very important to detect tampering in electric meters to ensure proper billing. Electric meter readers are trained to spot signs of tampering. The consumers who tamper with electric meter may be charged each billing period with the maximum rate until the tamper is removed, or in some cases the service may also be disconnected.Today, many modern meters can easily detect all of these effects. The owner of the meter normally secures the meter against tampering. Newer computerized meters usually have counter-measures against tampering. In order to find and fix power distribution problems, power companies today normally investigate discrepancies between the total billed and the total generated These investigations are an effective method of discovering tampering and security in electric meters.

Tamper Tests conducted on MetersSome customers, in order to receive lesser power tariffs, tamper with their respective meters. They tamper with their meters in order to slow down the meter running (the impulses frequency) and reduce their power bills. Normal consumer tampering is down via CT bypass, CT shorting. Modern day meters have been designed such as to record such tampering with the meters. The tampering with the CT load will also get recorded in the meter. The tamper report will indicate when the CT was shorted or was bypassed. It will show the time at which it was shorted/ bypassed and for how much time it was shorted/ bypassed. Here are some tamper tests that the meters are subjected to before being made available for public distribution:Voltage Failure:When the phase voltage becomes less than the set threshold value (def. 55% of basic Voltage) for more than 3 minutes, the meter indicates that Voltage failure has occurred. It records the time when it occurred and for how long it occurred.Current Failure:When the phase current becomes less than the set threshold value (def. 2% of basic Current) for more than 3 minutes, the meter indicates that Current failure has occurred. It records the time when it occurred and for how long it occurred.Voltage Unbalance:When the maximum of the 3 phase voltages subtracted by any other phase voltage is greater than the 30% of the basic voltage, then, the meter indicates a Voltage Unbalance. It records the time when it occurred and for how long did it occur.Current Unbalance:When the maximum of the 3 phase currents subtracted by any other phase current is greater than the 20% of the basic current, then, the meter indicates a Current Unbalance. It records the time when it occurred and for how long did it occur.Current Bypass:When the vec