What is creeping in induction type energy meter?

Creeping in the induction type energy meter is the phenomenon in which the aluminum disc rotates continuously when only the voltage is supplied to the pressure coil and no current flows through the current coil.

What do you mean by creeping error in induction energy meter and how it can be adjusted?

Creeping Adjustment : When a hole comes under a pole of shunt magnet, the disc tends to remain stationary in that position. Instead of drilling holes, a small piece of iron can be placed on the disc and when the iron piece comes near the brake magnet, it is attracted and make the disc stop.

What do you mean by creeping error?

Electrical Engineering (EE) Question In other words, the creeping is the kind of error in which the energy meter consumes a very small amount of energy even when no load is attached to the meter. The creeping increases the speed of the disc even under the light load condition which increases the meter reading.

What is creeping how creeping can be avoided?

Prevention of Creeping The creeping is avoided by drilling the hole in the disc. The holes are diametrically opposite to each other. The aluminium disc stops rotating even when the small edge of the disc come under the pole of the magnet. The holes will limit the revolution of the disc.

How creeping can be avoided?

Creeping can be prevented by providing two holes on the disc exactly opposite to each other. Whenever the hole comes under the shunt magnet, the disc stops rotating. Hence the rotation of the disc is opposed by this force and it will stop. In some cases, a piece of iron may be attached to the edge of the disc.

What is phantom loading and creeping?

Definition: Phantom Loading is a loading condition in which an energy meter is connected to factious or phantom load for testing of energy meter with high current rating. An energy meter is subjected to various kind of test like Creep Test, Starting Test etc.

What are the errors in the energy meter?

The causes for error-wiring of three-phase three-wire electric energy metering device may include: the connection error between transformer and electric energy meter, the error of current transformer polarity and the error of voltage transformer polarity.

How can we stop creeping in energy meters?

To prevent creeping, two diametrically opposite holes are drilled in the disc of energy meters. Due to this hole, the disc will come to rest when the hole comes under the edge of the pole of the shunt magnet. Thus creeping is limited to a maximum of half of the rotation.

What is the effect of friction in induction type energy meter?

In an induction type meter, creep is a phenomenon that can adversely affect accuracy that occurs when the meter disc rotates continuously with potential applied and the load terminals open circuited. The creeping error occurs because of the excessive friction. The main driving torque is absent at no load.

What is creeping how do we compensate this?

The main reason for creeping is the over compensation provided in order to overcome the static friction offered by Al-disc. Creeping can be reduced by making diametrically two opposite holes on Al-disc.

What is phantom load in energy meter?

Definition: Phantom loading is the phenomena in which the appliances consume electricity even when they turn off. The disc of the energy meter rotates which increases the reading of the meter, but the devices do not consume power. This type of loading is also known as the vampire or virtual loading.

What is creeping error in energy meter?

Creeping: Sometimes the disc of the energy meter makes slow but continuous rotation at no load i.e. when the potential coil is excited but with no current flowing in the load. This is called creeping. This error may be caused due to over compensation for friction, excessive supply voltage, vibrations, stray magnetic fields etc.

What is creeping in shunt magnets?

Using shading bands around the central limb of shunt magnet. Option 1 : Drilling two diametrically opposite holes in the disc. Sometimes the disc of the energy meter makes slow but continuous rotation at no load i.e. when the potential coil is excited but with no current flowing in the load; This is called creeping.

What is an induction type energy meter?

Basically an induction type energy meter is a form of a two phase induction motor. It has some inertia and so it could have an error due to the inertia if the supply fluctuates very fast. or if the supply has undesired harmonics on it. Also

What are the causes of creeping error in a potential coil?

The vibration, stray magnetic field and the extra voltage across the potential coil are also responsible for the creeping. The creeping error occurs because of the excessive friction. The main driving torque is absent at no load.