Every house, small factory, business establishment, shop or office needs at least one energy meter to register the power it consumes. Because of the government’s massive rural and urban electrification programme, there is a good demand for this product today
By Baishakhi Dutta
Energy meters are available in single phase and three phase versions, at different current ratings, as per the customer’s requirement. Of late, newly developed electronic energy meters are also available in the market. Since the technology involved to manufacture this product is fairly simple and replacement of spare parts is easy, the present demand and future prospects for this product are reasonably good.
Types of energy meters
There are three basic types of energy meters, as listed here.
- Electromechanical/standard meters: These are the most common type—the age old watt hour meters. They consist of a rotating aluminium disc mounted on a spindle between two electro-magnets, the rotation speed of which is proportional to the power that is integrated by the use of a counter mechanism and gear trains.
- Electronic meters: These are accurate and highly precise. They are available as analogue or digital measuring instruments, and are more dependable than conventional mechanical meters. They consume less power and start measuring instantaneously when connected to a load. An analogue meter converts power to a proportional frequency or pulse rate, and integrates it through counters placed inside it. In a digital electronic meter, power is directly measured by a high-end processor. Digital meters are straightforward as all you need to do to take a reading is to note down the first five figures on the digital display.
- Smart meters: These use advanced metering technology, which involves placing intelligent meters that measure energy consumption, remotely switch on the supply to customers and even control the maximum electricity consumption possible, thus reading, processing and sending feedback to users.
Buying tips
Customers should check some of the following critical parameters before making a purchase decision:
- Current carrying capacity
- Number of phases
- Critical electrical parameters
- Use of microprocessors
- Class of accuracy
- Connections done by licensed electrical contractors
A few products available in the market
Advance Metering Technology Ltd (AMTL)
Model: SEMC/SEML – ‘K’ series
Key features
- Complies with ISO:13779 and CBIP report No. 304
- State-of-art design with class 1.0 accuracy
- Liquid crystal display/stepper motor counter display
- Comprehensive tamper detection and tamper-proofing measures
- LED indication (SEML) for calibration, phase indication, earth load tampering and reverse tampering
- Displays/records cumulative active energy (kWh)
- Compact, sleek and packed in a dust-, moisture- and shock-proof (IP51) polycarbonate enclosure
Contact details: www.pkrgroup.in
Schneider Electric
Model: EM6400 multi-function meter
The EM6400 series of digital power meters offer comprehensive three-phase electrical instrumentation and load management facilities in a compact and rugged package.
Key features
- Accuracy class 1.0, 0.5, 0.5S and 0.2 as per IEC 62052-11/ IEC 62053-22
- Monitors all electrical parameters like phase, voltage, current, demand, W, VA, VAR
- Monitors all instantaneous and integrated parameters
- Neutral current, frequency, power factor, percentage of load, phase angle and THD
- Demand calculation method – sliding and fixed block, import/export monitoring
- CT reversal: Auto correction of energy integration in Star (WYE) mode
- Delta/STAR/2Ph/1Ph
- PT/CT primary and secondary
- UL, C UL listed, CE, C-Tick certified
- Metering voltage input range from 80V to 600V AC; L-LRS485 communication port with Modbus RTU protocol
Contact details: www.schneider-electric.com
HPL Electric & Power Pvt Ltd
Model: CT-2EMG
The CT-2EMG model enables communication on the RS485 Modbus. It works with RS485 on a master-slave configuration, where the CT-2EMG is the slave and the master can be a computer or PLC.
Key features:
- Measures kWh of two sources in one meter for a three-phase, four-wire LV electrical network
- Separate pulse output for mains/generator energy
- LCD with backlit display
- Three pushbuttons on the front panel for programming
- Flashing indicator is provided on the display to show the source in use
- Current reversal indication provided on the display
- Available in class accuracies of 1.0 and 0.5
- Separate models for AC and DC sensing
Contact details: www.hplindia.com
Looking for a single phase meter capable of monitoring:
Voltage, Current. Pf ,ad Kwh
will pick up one or two samples only intitially