The document discusses electricity meters and their operation. It begins by defining an electricity meter as a device that records electrical energy consumption or delivery. It then discusses the specifications and advantages of programmable digital meters over mechanical meters, including their wider measurement range and resistance to external influences. The document also covers the roles of LED indicators on meters and various meter wiring configurations and connections.
6. Specifications of Energy Meter:
Rating :
In : 3x5; Vn : 3x110V(L-L),
In : 3x30(100); Vn : 3x230/400V(L-L),
Starting Current :0.2%
Kwh, KVARH and MD in KW
TOU, 6 Tariff and 6 time zone
6 Month Billing data
RS232C
7. Why Mechanical meters read less?
Influence Parameters
Age
Wear and Tear
Narrow Range
Mounting
Dust and Oil effect
Mechanical Counters
8. Why electronic meters are preferred ?
Wide Range
Low starting current
Less effect of Influence
parameters
More accurate
Tamper proof
14. * In general Phase, current is
used for measurement. However
if neutral Current varies by more
than 10~ 12 % then Neutral
current selected
Good electronic meters have
Current sensors in both the
Phase path, and Neutral path
For Measurement, it chooses
higher * of the two current.
15. Electro-mechanical Meter has
Current sensor only on one wire
All Measurement based on
phase wire current even when
connected to neutral.
16.
17. 1.L and N swapped, load to
Earth
2. L and N swapped, load
partially connected to Earth
19. 3.L and N swapped, l/O swapped,
Load connected to Earth
4.L and N swapped, l/O swapped,
Load partially connected to Earth
20. Wrong wiring, among others things can
result in:
Safety hazards (wires are still live, even
when the main switch is off).
Cause fire (if by mistake, phase and
neutral wires get interchanged)
Wrong Current flow (neighbours current
can flow through your meter)
22. 1 2 3 4 1 5 6 7 8 9 10 11
LOAD
R
Y
B
N
WHOLE CURRENT METERING
Figure-1
N
Y
B
R
4
K L
k
1 2
i
3
K L K
6
k l
5
k
7
L
l
8 9 11
LT CT METERING
LOAD
Figure -2
Figure-3
Vector diagram of Figure-1 & 2
3
I
V 3
1
I
3
1
V 1
2
I2
2
V
Here
P= Total Power
P1= Power for phase-1
P2= Power for phase-2
P3= Power for phase-3
Balance Condition :
Voltage V1-n=V2-n=V3-n = V (P-n)
Current I1=I2=I3 = I
Phase Angle 1=23
P= P1+P2+P3
= V1.I1.Cos1V2.I2.Cos2V3.I3.Cos3
= 3 V.I.Cos
22
Connection Diagram of Whole Current & LT CT
Energy Meter
24. 3-Element 4-Wire
Figure-3.1
3
1 2
N
R
Y
B
v
V
u
v
u
U V U
v
u k
U V K L
l
11
8 9
6 7
4 5
LOAD
k
l
k
K L K L
l
CT & PT OPERATED (HT METERING) METER CONNECTION
3-Element 4-Wire
Figure-3.2
3
1 2
N
R
Y
B
v
u
U V
v
u k
U V K L
l
11
8 9
6 7
4 5
LOAD
k
l
k
K L K L
l
Y
B
R
2
v
u
v
u k
U V U V K
1
k l
i
L K L
7
5
3 8 9
LOAD
Figure-3.3
2-Element 3-Wire
Y
B
R
2
k
K
1
k l
i
L K L
7
5
3 8 9
LOAD
Figure-3.4
2-Element 3-Wire
v
V
u
v
u
U V U
v
u
U V
24
Connection Diagram of 3-Element 4-Wire & 2-Element 3-Wire
Energy Meter
28. Proper connection of 3-Element 4-Wire Energy Meter
R
B
N
Y
2
1
LOAD
5
3 4 7
6 9
8 11
k l k l k l
K L K L K L
U V
u v
U V
u v
U V
u v
CONNECTION CIRCUIT OF METER VECTOR DIAGRAM
Fig.-5-1
Voltage RED Phase open circuited
B
N
Y
R
U
u
V
v
U
u
V
v
LOAD
2
U
u
V
v
K
k
1
L
l
3
K
k
4 5 9
7
L
l k
6
K L
l
8 11
B
N
Y
R
U
u
V
v
U
u
V
v
LOAD
2
U
u
V
v
K
k
1
L
l
3
K
k
4 5 9
7
L
l k
6
K L
l
8 11
V 3
3
I
3
1
I
2
V
2
I
2
Similar for Yellow & Blue phase
V 3
3
I
3
1
V
2
V
2
I
2
Current RED Phase open circuited
V 3
3
I
3
1
I
1
1
V
2
V
2
I
2
CALCULATION
P= P1+P2+P3
= V1.I1.Cos1V2.I2.Cos2V3.I3.Cos3
= 3 V.I.Cos
Here
P= Total Power
P1= Power for phase-1
P2= Power for phase-2
P3=Power for phase-3
V1-n,V2-n ,V3-n = Phase voltage
1,2,3 = Phase angle between V & I
Balance Condition :
V1-n=V2-n =V3-n =V (p-n)
I1=I2 =I3 =I
1 =2 =3 =
P= 3.V.I. Cos
PF=2.V.I. Cos
CF=1.5
PF= P1+P2+P3
= 0V2.I2.Cos2V3.I3.Cos3
= 2 V.I.Cos
PF=2.V.I. Cos
CF=1.5
PF= P1+P2+P3
= 0V2.I2.Cos2V3.I3.Cos3
= 2 V.I.Cos
Balance Condition :
V1=V2 =V3 =V
I1=I2 =I3 =I
1 =2 =3 =
Balance Condition :
V1=V2 =V3 =V
I1=I2 =I3 =I
1 =2 =3 =
Similar for Yellow & Blue phase
Fig.-5-2
Fig.-5-3
FAULT ANALYSIS OF 3-ELEMENT 4-WIRE METERING
P= Total power in proper connection
= 3 V.I.Cos
PF=2 V.I.Cos
Correction Factor(CF)= P
PF
CF= 3 V.I.Cos2 V.I.Cos
28
Faulty Connection Analysis of 3-Element 4-Wire Energy Meter
29. Fig.-5-6
V
Fig.-5-5
Fig.-5-4
V
V
B
N
R
Y
U
u
Y
N
B
R
U
u
Y
N
B
R
U
u
Voltage Red and Blue Phase exchanged
V
v
v v
V
u
U
u
U
k
l
k
K L K
1 2 3 4
l
k
l
K
L L
6
5 7 8 9
LOAD
11
Current Red Phase incorrectly poled
Voltage Red Phase incorrectly poled
V
v
V
v
U
u
U
u v k
K L
l
K
k
1 2 3 4
V
v
V
v
U
u
U
u v k
K L
l
K
k
1 2 3 4
K
L
l k
L
l
6
5 7 8 9
LOAD
11
K
L
l k
L
l
6
5 7 8 9
LOAD
11
PF =P1+P2+P3
= V3.I1.Cos(120°+1)+V2.I2.Cos2
V1.I3.Cos(120°-3)
= V.I Cos(120°+)+Cos
Cos(120°-)
= 0
Similar for Yellow & Blue phase
Similar for Yellow & Blue phase
PF =P2+P3-P1
= V2.I2.Cos2V3.I3.Cos3
-V1.I1.Cos(180°+1)
= V2.I2.Cos2V3.I3.Cos3-V1.I1.Cos1
= V.I.Cos
PF =P2+P3-P1
= V2.I2.Cos2V3.I3.Cos3
-V1.I1.Cos(180°+1)
= V2.I2.Cos2V3.I3.Cos3-V1.I1.Cos1
= V.I.Cos
PF =V.I. Cos
I3
V 3
3
3
V 1
2
CF=
PF =0
1
1
I
I2
2
V
PF =V.I. Cos
CF=3
CF=3
-V
I3
3
V
3
1
1
I
2
3
I
3
V
3
1
V
-I1
2
1
1
I2
V2
I2
V2
CONNECTION CIRCUIT OF METER VECTOR DIAGRAM CALCULATION
Balance Condition :
V1=V2 =V3 =V
I1=I2 =I3 =I
1 =2 =3 =
Balance Condition :
V1=V2 =V3 =V
I1=I2 =I3 =I
1 =2 =3 =
Balance Condition :
V1=V2 =V3 =V
I1=I2 =I3 =I
1 =2 =3 =
FAULT ANALYSIS OF 3-ELEMENT 4-WIRE METERING
29
Faulty Connection Analysis of 3-Element 4-Wire Energy Meter
37. History of Energy Meter:
The first accurate, recording electricity
consumption meter was a D.C(Direct Current).
Dr. Hermann Aron, who patented it in 1883 in the
General Electric Company.
It is commercially introduced into Great Britain from
1888.
Aron's meter recorded the total energy used over
time, and showed it on a series of clock dials.
38. History of Energy Meter:
The first specimen of the AC kilowatt-hour meter produced
on the basis of Hungarian Ottó Bláthy's patent and named
after him was presented by the Ganz Works at the
Frankfurt Fair in the autumn of 1889, and the first
induction kilowatt-hour meter was already marketed by the
factory at the end of the same year. These were the first
alternating-current wattmeters, known by the name of
Bláthy-meters.
39. History of Electromechanical Energy Meter:
The most common type of electricity meter is the Thomson
or electromechanical induction watt-hour meter, invented
by Elihu Thomson in 1888.
The electromechanical induction meter operates by
counting the revolutions of an aluminum disc which is
made to rotate at a speed proportional to the power. The
number of revolutions is thus proportional to the energy
usage.
It consumes a small amount of power, typically around 2
watts
40. Classification of energy meter:
According to their Specification:
Energy Meter
Single phase Three phase and
three wire
Three phase and
four wire
1.Single phase: reference voltage: 220V
2. Three phase and three wire: reference voltage: 3X100/110V
3. Three phase and four wire: reference voltage:
3X57.7V/100/110V, 3X220V/380/415V
41. Classification of energy meter:
According to their connection:
Energy Meter
Connection through
transformers
Direct connection
1.Current from connection through transformers: 3X0.3 (1.2) A,
3X0.5 (2) A, 3X1.5 (6) A, and 3X5 (6) A, etc.
2. Current from direct connection: 3X5 (20) A, 3X10 (40) A, and
3X30 (100) A, etc
42. Classification of energy meter:
According to their Measuring Accuracy:
Energy Meter
Watt-hour Var-hour
1.Watt-hour accuracy class: 0.2S, 0.5S, 0.5, 1.0,2.0.
2.Var-hour accuracy class: 0.2S, 0.5S, 0.5, 1.0,2.0.
43. Classification of energy meter:
According to purposes, energy meters can be divided
into:
Single phase energy meter
Three-phase watt-hour energy meter
Three-phase var-hour energy meter
Maximum demand meter
Multi-rate energy meter (time-based)
Multifunctional watthour meter
Copper loss meter
Iron loss meter
Prepayment energy meter
44. What is power?
Electric power is the rate at which electrical energy is
transferred by an electric circuit. That means
Power = Energy(Work done) / Time
The SI unit of power is the watt(named after the
scientist James Watt) that means one joule per second.
1 Watt = 1 Joule / Second.
A 100 watt light bulb is a device that converts 100 joules of
electrical energy into 100 joules of electromagnetic
radiation (light) every second.
45. What is power?
The electric power in watts produced by an electric
current I consisting of a charge of Q coulombs every t
seconds passing through an electric potential (voltage)
difference of V is
where
Q is electric charge in coulombs
t is time in seconds
I is electric current in amperes
V is electric potential or voltage in volts
46. What is Energy?
The term energy defines the amount of power consumed
/delivered over the period. That means..
Energy = Power x Time.
1 kilo-watt hour = the energy delivered by 1000 watts of
power over over a one hour time period. That means…
Energy = Power x Time
= (1000 Joules/Second) x (3600 Seconds)
= 3,600,000 Joules = 3.6 million Joules!
That's a lot of Joules! So you see that kilo-watt hours is a
much better unit for large amounts of energy a one hour
time period.
52. Benefits of Phasor Analysis:
Provide visual verification of errors in service
wiring
Minimize or eliminate the need to use instrument
meters (volt, amp, phase angle)
Facilitate the detection and trouble-shooting of:
Cross-phased wires
Wrong application
Wrong CT and PT polarity
53. Energy meter testing Procedure:
1.First Process:
With the help of a duly calibrated standard lamp of 1000 watt:-
A 1000-watt lamp if energized for one hour would consume one
unit of electrical energy.
Switch off all electrical lamps/appliances, etc., in your house.
Percentage error =
(energy registered by the meter – true energy) × 100
true energy
54. Energy meter testing Procedure:
2.Second Process:
With the help of Meter constant which is indicated in the Meter
Body. e.g. X impulses /kWh i.e. X impulses per unit i.e. X times
blinking of LED installed on meter for 1 unit consumption of
electrical energy.
We may cross check this meter constant by actually counting the
blinking of LED e.g. one unit should be registered by the meter in
3200 impulses i.e. 3200 times blinking of LED or ½ unit should be
registered in 1600 impulses or ¼ unit should be registered in 800
impulses and so on. If meter constant indicated on the meter
matches with your actual impulse count/number of blinks of LED, it
means that the meter is running ok.
55. Energy meter testing Procedure:
3.Third Process:
With the help of a Voltmeter, Ammeter, Switch and a Stop
Watch:- Connect the Switch (SW), Voltmeter (V) and Ammeter
(A) as shown in the following circuit diagram:
S.L
N.O
Energy Meter
Initial Reading
(kWh) (X)
Energy
Meter
Final
Reading
(kWh) (Y)
V
(Volts)
I
(Amps)
T
(Seconds)
Energy by
calculation =
Vlt/1000x3600
(kWh)
Energy Meter
Reading (X)-(Y)
(kWh)
56. Energy meter testing Procedure:
4.Fourth Process:
With the help of a Meter Testing Set:
PWS-2.3,
PEWM-3CF,
PRS-1.3,
EDI
57. IEC Standards for meter testing:
S.L
N.O
IEC Standard N.O. Purpose
01. IEC 62053-11 For electromechanical meters
02. IEC 62053-21 For electronic meters
03. IEC 62052-11 For general requirements, tests & test conditions of
metering equipments.
61. `
MD Manager
`
MD Manager
`
Web Browser
`
Web Browser
MultiDrive Servers
PowerSignature
Servers
MultiDrive
Comm. Servers
MD COM API
RADIO
DIRECT
P
L
C
/
D
L
C
G
P
R
S
/
E
D
G
E
/
3
G
GSM
Database Servers
PLC / DLC
Concentrator
RS232 / RS485
Convertor
TCP/UDP
Total Connectivity
64. Frequently Answer Question:
Q. Why are electricity bills getting inflated after replacement of old
electromechanical meters by new electronic meters by the utilities?
A : 01: Energy consumed by the consumer is actually high.
02. New meter is working satisfactorily but the wiring to meter,
which was done earlier as per old electromechanical meter was
not correct.
