What is the function of energy meter?

Answer 1

An electric meter or more commonly used term, the electricity meter is meant for measuring the total electrical energy consumed in a house, shop, offices etc and the units of measurements are usually kilowatt-hour (KWh). The electric meter working involves computing the integral over time of the electrical power in Watts consumed on the power network delivered to a particular connection. This electrical power is measured by performing the product of the line current in Amps and the line voltage in Volts.

Let us know have a look at the working of an electric meter. The electric meters generally comprises of two parts -- a transducer to convert the power into a mechanical or electrical signal, and a counter to integrate and display the value of the total energy that has passed through the meter. One of the easiest and the simplest ways to measure the line current and voltage for single phase electronic meters are line current and line voltage.

In multi-phase meters (many homes have 2 or 3 phases of electricity supply, providing more power), voltage and current measurements have to be electrically isolated for each phase and Transformers are used instead of shunts for current sensing.

Let us have a look at the working of an electric meter which is meant for residential connections. Usually domestic electric meter is enclosed in a glass case in which contains a revolving disk which in turn rotates a series of numbers or dials. When the electric current passes through the meter, the disk rotates to measure the exact amount of kilowatts used. The speed of rotation varies depending on how much electricity you are using in your house for particular device such as running a washing machine, microwave and water heater etc. It is important to note that different electric appliance uses different amount of electricity for its operating. More the utilization of electric power, the faster the speed of rotation of disks.

The electric meter working in case of watt hour meters is explained here. The electromechanical type meter has the spinning wheel in it and the other type of meter is a solid state type. The solid-state types make use of a current transformer to measure the current produced in the current-carrying conductors, which means that the current carrying conductors need not be connected to the actual measuring device. The electromechanical type uses an aluminum disc acted upon by two coils. One coil is positioned in such a way as to produce a magnetic flux in proportion to the voltage on the disc, and the other coil produces magnetic flux proportional to the current.

Answer 2

The metallic disc is acted upon by two coils. 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 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 and voltage. A permanent magnet exerts an opposing force proportional to the speed of rotation of the disc - this acts as a brake which causes the disc to stop spinning when power stops being drawn rather than allowing it to spin faster and faster. This causes the disc to rotate at a speed proportional to the power being used.

Answer 3

An 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]. ...@Prashant

Answer 4

Energy meter works on the same principle as the induction motor. An aluminium disc is placed inside a magnetic core with two limbs. One carries a voltage coil so its flux is proportional to voltage, the second carries a current coil so its flux is proportional to current. The two fluxes induce eddy currents into the disc, each of which interacts with the flux of the other to produce a torque, which accelerates the disc. This torque of course is proportional to flux × the eddy current, which equates to V × I, or power. A permanent magnet creates another eddy current resulting in a torque proportional to speed that brakes the disc, the combined result of these actions is that the speed of the disc is proportional to power, and the total number of revolutions is proportional to the energy that has passed through the meter. The disc drives a chain of gears that turn a mechanical counter, called a 'register'.

Answer 5

An energy meter measures the amount of energy used on an electrical circuit. Inline energy meters can be bought which plug into the socket and then an appliance is plugged into the meter, which thereafter records the amount of power and energy used by the appliance.

Answer 6

The KWH meter measured the energy (voltage and current) being used in its watt-hour tally.

Answer 7

To measure electrical parameters like voltage, current, power factor etc.