What is Creeping in Energy Meter？

What is Creeping in Energy Meter？

Definition

Creeping in an energy meter is a phenomenon where the aluminium disc rotates continuously when only voltage is applied to the pressure coil and no current flows through the current coil. In essence, it is an error causing the energy meter to consume a minute amount of energy even when no load is connected to the meter.

Impact and Causes of Creeping

Creeping can increase the disc's rotation speed even under light - load conditions, leading to inflated meter readings. Factors such as vibration, stray magnetic fields, and excessive voltage across the potential coil contribute to this phenomenon. The root cause of creeping error often lies in excessive friction. At no - load, the main driving torque is absent, so the disc rotates due to the additional torque from the compensating vane.

Prevention of Creeping

Creeping can be prevented by drilling two holes diametrically opposite each other in the disc. When a small edge of the disc passes under the pole of the magnet, the holes cause the aluminium disc to stop rotating. This effectively limits the disc's revolution. A better understanding of this action can be gained by referring to the figure below.

When a hole in the disc comes under the pole of the magnet, the circular path of the eddy currents in the disc is disrupted. Let (A') denote the center point of the magnetic pole generated by the current. The force exerted on the disc causes the center point (A') to shift away from the axis A of the magnetic pole.At no - load, the disc rotates until the holes align with the edges of the magnet. In this situation, the disc's movement is counteracted by the torque produced.In certain instances, a small piece of iron is affixed to the edge of the disc. An attractive force then arises between the pole magnets and the iron piece, effectively preventing the disc from creeping.