Creeping in energy meter is the phenomenon in which aluminium disc rotates when only voltage is supplied across the pressure coil i.e when no current is flowing through the current coil. In other word, creeping is the kind of error in which energy meter consumes a very small amount of electricity although when no any load is connected to it.
The creeping increases the speed of the disc even when the energy meter is connected to the light load which increases the energy meter reading i.e energy consumption cost. The creeping error is also due to vibration and stray magnetic field and extra voltage across potential coil.
The creeping error occurs because of the excessive friction. Due to friction, the main driving torque is reduced and absent at no load. Hence, the disc rotates because of the additional torque provided by compensating vane.
Prevention of Creeping Error
There are two methods to avoid the creeping error which are listed below.
- Drilling Hole in the Disc
- Attach Iron Piece to the Disc Edge
Drilling Hole in the Disc
The creeping is avoided by drilling the hole in the aluminium disc. This hole distort the magnetic field keeping disc still when it should be still resulting no creeping error.
Attach Iron Piece to the Disc Edge
The creeping error can also be avoided by attaching little piece of iron to the disc's edge. These pieces interact with pole magnets creating a force that opposes the creeping effect keeping disc still when it should be still resulting no creeping error.