Electromechanical meters, Electrical Engineering

Electromechanical Meters

Electromechanical energy meters are based on the Ferraris Principle (see note in the margin). The working of these meters is explained.

Working of Electromechanical Meters

The meters have a revolving metallic disc mounted on jewel bearings or magnetic suspension bearings. The display is cyclometer or mechanical counters and accuracy is classically 1% or 2% (class 1.0 or 2.0). They  cater  to  limited  tariffs  applicable  majorly  to  1-phase  or  3- phase direct connected segment (whole current meters).The electromechanical induction meter operates through counting the revolutions of the disc that rotates at a speed proportional to the power consumed. 

The number of revolutions is, therefore, proportional to the energy usage.  The metallic  disc is acted upon through three magnetic fields,  one  proportional  to the voltage,  the other  to the current  and  a third  constant  field  supplied  by  a  permanent   magnet.  One  of  the varying  fields  induces  currents  in  the  metallic  disc,  that  are  then acted upon through the other varying field to produce a torque.

This  results  in  the  torque  being  proportional  to  the  product  of  the current  and voltage,  that is power.  As the metallic disc rotates through the permanent magnetic field, eddy currents are again produced that dissipate energy (because the disc has some resistance) and act to slow the rotation. This drag is proportional to the rotation speed. The equilibrium among the applied torque and the drag results within a speed proportional to the power. The rotating disc in this category of meter is, actually,  an  electric  motor  of  a category  known as  a reluctance  motor  or  eddy current motor. It consumes a little amount of power, classically around 2 W.

Posted Date: 2/6/2013 6:54:55 AM | Location : United States







Related Discussions:- Electromechanical meters, Assignment Help, Ask Question on Electromechanical meters, Get Answer, Expert's Help, Electromechanical meters Discussions

Write discussion on Electromechanical meters
Your posts are moderated
Related Questions
I want project ideas.

Explain the Voltage Regulation? The percent of voltage regulation of a generator is defined as the ratio of the change in voltage from no-load to full-load to the full-load vol

Considering Figure, let balanced positive-sequence, three-phase voltages with ¯V AB = 100√3 0° V (rms) be applied to terminals A, B, and C. The three-phase wye-connected balanced

Q. Mode of propagation of electromagnetic waves? The mode of propagation of electromagnetic waves in free space and atmosphere may be subdivided into three categories: • Gro

Question: (a) The conversion of a time varying analog audio signal into digital form is carried out using an electronic circuit known as a (signal) encoder. Draw a labeled bl

Speed  Control of Three  Phase Induction Motors Three  phase  induction motors are invariably used in the application where in speed in  required to be  constant  or adjustabl


There is a requirement to propose a new ASIC design flow within your company, from VHDL design capture through to GDSII tape out.  It is very important that the flow includes all t

I would like to know the materials needed for electrostatic sprayer.