What is creeping error in an 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 is creep error?

Creep error characterizes the drift of the signal over time while a rapidly applied load is kept constant on the sensor. It is characterised by the relative difference in the signal when loading at full scale and after 30 min. under the same conditions.

What are the errors in single phase energy meter?

Clarification: In an energy meter, phase angle errors occur as a result of improper adjustments of lag condition, abnormal frequencies etc. Due to temperature, changes in resistance values also lead to error in the phase angle.

What is creeping in measurement?

Creeping is the phenomenon in which the energy meter still shows some minimal energy consumption when there is no load attached to the meter. This is due to some inherent real world noise and it causes inconvenience to customers as they will be billed even if they have not consumed any electricity.

What is creeping and how it is eliminated?

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.

How do you stop creeping?

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.

What is creeping error in energy meter how it is avoided?

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 error is compensated?

The creeping error occurs because of the excessive friction. The main driving torque is absent at no load. Hence the disc rotates because of the additional torque provided by the compensating vane.

How creeping error can be minimized 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.

Why does a creeping error occur?

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. Hence the disc rotates because of the additional torque provided by the compensating vane.

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 phase error in energy meter?

Phase Error: It is necessary that the energy meter should give correct reading on all power factors, which is only possible when the field setup by shunt magnet lags behind the applied voltage by 90o. But the flux due to shunt magnet does not lag behind the applied voltage exactly by 90o because of winding resistance and iron losses.

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.

Why are there errors in my energy meter?

Energy Meter Errors In addition to errors due to incorrect settings of the main adjustments, there are errors in meter registrations due to other causes. The more important of these are described briefly below, together with some compensations which are frequently incorporated in meters to minimize the errors.