Types of Electric Meters

Electric meters measure the amount of electric current supplied to a shop, house or any other source including machines. The electricity board has different terms and conditions for installing various electric meters depending on their usage. These meters help in measuring the amount of electricity being utilized by various sections of society, and therefore, should not be tampered with.

Electricity cannot be stored in large amounts, and hence, needs generators to produce it. The need of generators would be endless if electricity is not used efficiently. Electric meters are designed to reduce power consumption during peak hours and also control the power supply to different consumer sections.

Electric meters are broadly classified into two categories – electromechanical meters and electronic meters. Further, they can be of various types such as numeric display meters, standard meters, variable rate meters, prepayment meters, electromechanical meters, etc.

Numeric Display Meters – The numeric display meters display the reading in a numeric form. The first five numbers should be read in these meters starting from left to right.

Electromechanical Induction Meter or Standard Meter – The most commonly used electric meter is electromechanical induction meter or standard meter that operates by counting the revolutions of an aluminium disc. It measures the electricity in kilowatt-hours. In this case, the units are charged at the same rate throughout the day. The electric energy being used is directly proportional to the number of revolutions of the disc. These types of meters are generally used on single phase AC supply.

Variable Rate Electric Meters – The variable rate electric meters give two different types of readings depending on the day and night time. They are also known as ‘economy 7’ meters, often used by suppliers and industrialists. Usually, their rate is cheaper at night.

Prepayment Electric Meters – The prepayment electric meters accept tokens or prepaid cards to get electricity supply. The customer has to pay the charges for the power supply in advance. One can also top-up the amount for extending the period of electric supply or when the balance over the supply is automatically cut off by a relay in the electric meter. This is common in rented accommodations.

Solid State Electric Meters – The solid state electric meters can be read automatically and their power displayed on an LCD screen. They calculate and show the exact value of the electricity consumed rather than its amount. The rate of the unit consumed varies according to the time and day of the week. They can also record, supply and load parameters such as power factor, reactive power, maximum demand, etc. Such types of meters use the remote meter reading technology.

Electronic Meters – The latest electronic meters are based on automatic meter reading or remote meter reading technologies. They use GSM, GPRS, Bluetooth, etc. to transfer the information related to power consumption. They store the usage profiles and the load requirements of a consumer and process it accordingly. Electric meters also help in detecting energy theft or any attempts at meter tampering with the help of their inbuilt automatic sensors.