What is Creeping?
In some meters, a slow but continuous rotation is obtained even when no current is flowing through the current coil and only the pressure coil is energized. This is called creeping. The major cause for creeping is over-compensation for friction. If the friction compensating device is adjusted to give a driving torque to compensate for starting friction which is bigger than the running friction there is a tendency for the disc to run even when there is no current through the current coils because the friction compensating torque is independent of the load current as the compensating device is voltage actuated. The other causes of creeping are excessive voltage across the potential coil (which is responsible for the production of excessive torque by the friction compensating device), vibrations, and stray magnetic fields.
To prevent this creeping two diametrically holes are drilled in the disc; the disc will come to rest with one of the holes under the edge of a pole of the shunt magnet the rotation being thus limited to a maximum of half a revolution. If a hole is under the edge of a pole, the circular eddy-current paths in the disc will be distorted as shown. The effective center of the eddy-current paths is then at A’ and this point is the central point of the equivalent magnetic pole produced by the currents. Examination of polarities shows that there is a resulting force on the disc, tending to move A’ away from the pole axis A. Thus the disc may creep until the by-hole reaches a position near the edge of a pole, but further movement is opposed by the torque produced in the manner just described. The magnitude of this torque is not sufficient to affect the action of the meter on load.
Creeping
Note:- In order to measure energy we have to measure power which is measured by the current coil and potential coil.
Therefore, we require two coils in the energy meter.
Energy Meter
Energy meters play a crucial role in measuring and monitoring electrical energy consumption, enabling fair billing, promoting energy efficiency, and supporting the management of power distribution networks. These meters come in different forms, including analog, digital, smart meters, and advanced metering infrastructure (AMI). There are various types of energy meters, which have several functions. It is used for household or domestic purposes for measuring electricity bills. In this article, we will go through what is energy meter?, construction with its operations, Then we will go through its types and finally, we will conclude our article with its Advantages, Disadvantages, and characteristics.
Table of Content
- Energy Meter
- Construction and Working
- Operation
- Types
- Advantages and Disadvantages
- Characteristics