in this article we will learn about the induction type energy meter. we will learn about the application of induction type energy meter.
Induction type energy meter
Energy is total power delivered or consumed over a time
interval,
Energy = power x Time
Electrical energy developed as work or dissipated as heat
over an interval time t
Energy is an integrating type of instrument used for measurement
of energy in domestic and industrial AC circuits.
Single phase induction type energy meter
Construction of induction type energy meter
In induction type energy meter mainly four part
1. Driving system
Consists of two electromagnets made of silicon steel
laminations.
Coil of one of the electromagnet (shunt magnet) is excited
by load current known as current coil.
Coil of second electromagnet (series magnet) is connected
across supply and carries a current proportional to voltage known as pressure
coil.
Copper shading bands whose position is adjustable are
provided on central limb to bring the flux exactly in quadrature with the
applied voltage.
2. Moving system
Consist of an aluminum disc mounted on a light alloy shaft positioned
in the air gap between magnets.
Shaft is pivoted on jewel bearings and a pinion engages it
with counting or registering mechanism.
3. Breaking system
Breaking torque is required to control the speed of moving
system. A permanent magnetism positioned near the edge of the aluminum disc to
provide breaking torque.
This magnet induces eddy currents that produce the braking
torque proportional to the speed of moving system.
4. Registering or counting mechanism
Records continuously a no. proportional to the revolutions
made by moving system.
Train of gears drives a series of 4 or 5 pointers. There are
two types of registers- pointer type and cyclometer register.
Adjustments of induction type energy meter
Some adjustments are carried out in energy meters so that
they read correctly. They are,
1. Preliminary light load adjustment
Disc is so positioned that the holes are not under neath the
electromagnets.
Reated voltage applied to pressure coil with no current in
current coil.
Light load device adjusted until disc just fails to start.
2. Full load unity power factor adjustment
Rated voltage applied to pressure coil.
Rated full load current at upf passed through current coil.
Position of brake magnet adjusted so that disc revolves at
correct speed.
3. Lag adjustment (low power factor adjustment)
Rated voltage applied to pressure coil.
Rated full load current at .5 pf lagging passed through
current coil.
Lag device adjusted so that disc revolves at correct speed.
4. Full load unity power factor adjustment and low power factor adjustment
Rated voltage applied to pressure coil.
Rated full load current at upf passed through current coil.
Full load unity power factor adjustment and low power factor adjustment done so
that disc revolves at correct speed.
5. Light load adjustment
Rated voltage applied to pressure coil.
Low current passed through current coil at upf.
Light load adjustment done so that disc revolves at correct
speed.
Full load unity power factor and light load adjustment are
gain done so that disc revolves at correct speed.
Performance is rechecked at .5 pf lagging.
Creep adjustment—pressure coils excited by 110% of rated
voltage with zero load current. At this condition meter should not creep.
Hence it is the working of induction type energy meter , adjustment of induction type energy meter.if you want to know more about the induction type energy meter you must watch this video.