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Technical Specifications for DT Metering 3-phase
Final Draft
TECHNICAL SPECIFICATION FOR
STATIC ELECTRICITY METERS FOR DT METERING
(3 phase 4 wire, class 0.5)
SECTION – I
TECHNICAL SPECIFICATIONS FOR STATIC ENERGY METER
(3 phase 4 wire, class 0.5)
1.0
SCOPE
The specification covers design, engineering, manufacture, assembly, inspection, type
testing, testing at manufacturers’ works before dispatch, packing supply and delivery at
site, subsequent storage, erection and commissioning at site (if specified) (including
handling, insurance during transit and storage), of Class 0.5 accuracy (0.5 for kWh &
1.0 for kVARh, LT, fully static electronic metering system, CMRI (if specified) and
software as per requirement given in this specification.
The meter shall be intended to be used for DT metering where metering shall be done
on the LT side. All mounting accessories including necessary hardware etc shall be
supplied and erected by the contractor. The meter alongwith CT shall be housed in an
LT distribution box with IP-54 degree of protection, on the trasformer body or at
sufficient height on the pole.
The meter shall be 3-phase 4-wire type suitable for connection to 3 phase 4 wire system
through built in or external CT of 5A secondary current. CT shall be provided in the
neutral circuit also, in case of 3 phase meters. The meter shall be capable to record &
display kWh, and maximum demand in kW, kVA & tamper events in line with this
specification.
The meter shall be provided with TOD feature for minimum eight time zones (eight
registers), each operative at specified time intervals corresponding to minimum four
different tarriffs.
The meter shall have BIS mark of certification and shall meet the requirements of
Central Electricity Authority Regulations, 2006 for Installation & Operation of Meters.
DT meter installation if covered shall be specifically included in the scope of works.
The system shall be operated by the supplier for 2 years. Any problems arising out of
first set of readings & analysis shall be resolved to the satisfaction of the owner.
Group of DT’s connected with each 11kV feeder shall be identified & energy audit for
the feeder as well as DT shall be possible with the software supplied.
Meters integral with CT, with thread-through arrangement shall also be acceptable.
Page 1 of 24
Technical Specifications for DT Metering 3-phase
Window type or base mounted CT’s shall be used (bar type or bus-bar type CT’s shall
not be used). Block CT’s shall be used so that they terminate directly on to the meter,
thereby making the CT secondary pratically inacccessible. The connections shall be
with minimum 2.5 sq.mm. copper cables.
2.0
STANDARDS APPLICABLE
Unless otherwise specified elsewhere in this specification, the performance & testing of
the meters shall conform to IS 14697. The following Indian/International standards and
all related Indian/International standards shall be referred whereever required & shall
be read with up to date and latest amendments/revisions thereof.
Sl. No.
Standard No.
Title
1
CBIP Report No.88 (revised Specification for AC Static Electrical
July 1996) with
Energy Meters
amendments (April 99-Sep99)
2
CBIP Technical Report
No.111
Specification for Common Meter
Reading Instrument
3
CBIP Technical Report
No.93
Study on tamper-proof methods for
energy meters.
4
IEC 62052-11 & 6205321/22
Specification for AC static transformer
operated Watt hour & VAR hour
Meters Class 0.2, 0.5 & 1.0 S
5
IS 14697
Specification of AC Static Transformer
operated Watt hour & VAR hour
meters – class 0.2 & 0.5 S
6
IEC-61000-4, 5 & 6
EMI/EMC Withstand
7
ANSI/IPC-A-610
Workmanship standard for
acceptability of electronic assemblies
(Standard developed by Institute for
Interconnecting & packaging circuits)
8
Central Electricity
Installation & Operation of Meters
Authority Regulations, 2006
9
ANSI/IPC-A-610
Workmanship standard for
acceptability of electronic assemblies
(A standard developed by Institute for
Interconnecting & Packaging Circuits)
10
IS 11000
Fire hazard testing
11
IS 12346
Testing Equipment for AC Electrical
Energy Meters
12
IS 11731
Methods of test for determination of
the flammability of solid electrical
insulating materials when exposed to
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Technical Specifications for DT Metering 3-phase
an igniting source
3.0
13
ISO 75-1 & 2
14
IS 9000
15
IS 5133
16
IS 12063
Classification of degrees of protection
provided by enclosures of electrical
equipment
17
IS 14772
General Requirements for Enclosures
for Accessories for Household and
Similar Fixed Electrical Installations Specification
18
IS 15707
Testing, Evaluation & Maintenance of
AC Electricity meters – Code of
Practice
Basic environmental testing procedures
for electronic and electrical items
CLIMATIC CONDITIONS
The meters to be supplied against this specification shall be suitable for satisfactory
continuous operation under the following tropical conditions. Meters shall be capable
of maintaining required accuracy under hot, tropical and dusty climate.
4.0
i)
Maximum Ambient Air Temperature in shade
: 55oC
ii)
Minimum Ambient Air Temperature
: -10oC.
iii)
Maximum Relative Humidity
: 95% (non-condensing)
iv)
Minimum Relative Humidity
: 10%
v)
Height above mean sea level
: Upto 2200 meters
vi)
Average number of tropical monsoon months
(conditions/annum)
: 5 months
vii)
Annual Rainfall
: 100 mm to 1500 mm
vii)
Wind pressure
: 200 kg /sqm
SUPPLY SYSTEM
Rated pressure coil operating voltage
230 Volt (phase- neutral)
Highest system voltage
433 V phase to phase
Rated Frequency
50 Hz
Standard basic current
5A
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Technical Specifications for DT Metering 3-phase
Note : In case of outdoor meters with built-in integral CT, rated current will be
specified by the utility based on full load current of distribution transformer.
4.1
POWER SUPPLY VARIATION
The meter should be suitable for working with following supply system variations.
5.0
Parameter
Operating range
Operating Voltage
70% to 120% of rated Voltage
Frequency
50 Hz + 5%
POWER FACTOR RANGE
The meter shall be suitable for full power factor range from Zero (lagging) through
Unity to Zero (leading).
6.0
ACCURACY
The class of accuracy of meters shall be 0.5. The accuracy should not drift with time.
For meters with built-in CT’s, overall accuracy of class 1.0 shall be acceptable. Testing
of meters with built in CT’s shall be carried out in line with the requirements of IS
14697 for accuracy class 1.0.
7.0
STARTING CURRENT
The meter shall start registering energy at 0.1% of the basic current and shall be fully
functional within five seconds after the rated voltage is applied. Starting current of
0.2% shall be acceptable for combined accuracy of CT & meter in case of meters with
integral CT.
8.0
MAXIMUM CONTINUOUS CURRENT Imax
The maximum continuous current in meters at which the meter purports to meet the
accuracy requirements shall be 200% of standard basic current specified in clause 4.0.
9.0
FUNCTIONS
9.1
DISPLAY FUNCTIONS
9.1.1.
The measured value(s) shall be displayed on seven digit Liquid Crystal display (LCD)
display unit, having minimum character height of 8.5 mm. LCD shall be TN type or
better suitable to withstand 700 C. When the meter is not energised, the display need
not be visible. Each display shall be retained for a minimum period of 5 S.
9.1.2. The data should be stored in non-volatile memory (NVM) with a data storage capacity
of at least 40 days with all data capturedby the meter including tampers. The nonvolatile memory should retain data for a period of not less than 10 years under nopower condition. Battery back-up memory will not be considered as NVM.
9.1.3. In case of multiple values presented by a single display, it shall be possible to identify
each displayed value/parameter through separate symbol/legend to be made available
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Technical Specifications for DT Metering 3-phase
on the display itself.
9.1.4. In addition to providing serial number of the meter on the display plate, the meter serial
number shall also be programmed into meter memory for identification through
CMRI/meter reading print out.
9.2.1
DISPLAY OF MEASURED VALUES
The principal unit for the dislayed values shall be the kWh, kVA & kVARh. The
display shall be visible from the front of the meter.
Note: For testing purposes a means of reading the energy register to within 0.01 kWh
resolution shall be provided. This may be via the display or by other means, e.g. a local
communication interface.
9.2.2 MINIMUM DISPLAY CAPABILITY
The following information shall be capable of being displayed:
(i)
Cumulative energy - kWh, kVAh & kVARh only in case of 3-phase meters
(ii)
Maximum Demand in kVA with occurrence of time
(iii)
Date/Time
meter shall be operated from an internal real-time clock & the time shall also be capable
of being displayed.
9.2.3
INDICATORS
The following parameters shall be displayed on pressing the push button(s):
i. LCD segment check.
ii. Real Time
iii. Date – dd, mm, yy
iv. Cumulative power-on hours
v. Cumulative MD reset count
vi. Cumulative Active energy forwarded (kWh) for previous six months
vii. Cumulative Reactive energy (kVARh) both lag & lead separately
viii. Cumulative Apperant energy (kVAh)
ix. Instantaneous phase voltage & current – Three phase or single phase as per
requirement
a. R Phase to neutral voltage
b. Y Phase to neutral voltage
c. B Phase to neutral voltage
x. Supply Frequency (Hz)
xi. Instantaneous load in –kW, kVA & kVAR
xii. MD – Active/Apperant
xiii. Power factor – Average for billing period
Page 5 of 24
Technical Specifications for DT Metering 3-phase
xiv. Power factor – Instantaneous
xv. Frequency
xvi. Tamper indication
9.3
RECORDING FUNCTIONS
The register shall be able to record and display starting from zero, for a minimum of
1500 hours, the energy corresponding to rated maximum current at reference voltage
and unity power factor. The register should not roll over in between this duration.
The meter shall have capability to log load-survey-data for multiple parameters.
Typically the data logging shall be done at half hour intervals.The data logged shall be
stored in meter memory & facility for downloading throuh CMRI shall be provided.
Manufacturer shall also provide Application program interface (API) suitable for the
meter for interoperability. The interoperability software shall provide common
framework for data collection & conversion to XML format.
DT meter shall record the following minimum parameters
10.0

Half hourly logging of kW, kVA, kVAR (for 3-phase meters), current &
Voltage (phasewise)

Half hourly logging of kWh (cumulative)

Duration of power avilability or power outage in minutes during each half hour
duration.

Phasewise kW & kVAR at peak kVA
SECURITY FUNCTIONS
Physical protection – shielding against magnetic fields; preventing entry of
foreign objects; fail-safe techniques in the design of components.
11.0
COMMUNICATION PORT
The meters shall have a galvanically isolated continuous rated heavy duty optical
communication port (RS232/RS485/RFID port) as per PACT/ ANSI/IEC 1107/IEC
62056 DLMS series in front of the meter, so that it can be easily connected to a handheld common meter reading instrument for data transfer and subsequently can be
hooked to a remote meter reading device through PSTN/GSM/Radio modem/PLCC
etc.
Additionally, the meter shall have a built-in Low Power Radio (LPR) or GSM modem
as desired by the utility. LPR shall function on a frequency allotted by Government of
India & shall have minimum range of 100m line of sight. It shall be possible to
download data for one month in about 5 minutes.
Mutually agreed tests (as agreed at the time of award) shall be carried out to verify data
trasfer & communication capability at third party laboratories.
12.0 TIME-OF-USE METERING FACILITIES
The meter shall include (wherever required to be supplied) facility of TOD metering for
Page 6 of 24
Technical Specifications for DT Metering 3-phase
minimum eight time zones. A sample of utilisation of time zones is tabled below. The
exact time slots shall be informed to the manufacturer after award.
Sl. No.
Duration
Display parameters
1.
06.00 to 09.00 hrs.
kWh, MD (kW)
18.00 to 21.00 hrs.
2.
22.00 to 05.00 hrs.
kWh, MD (kW)
3.
09.00 to 18.00 hrs.
kWh, MD (kW)
21.00 to 22.00 hrs.
05.00 to 06.00 hrs.
4.
00.00 to 24.00 hrs.
kWh, kVAh & MD (kW)
It shall be possible to reprogram the time slots.
13.0 GENERAL & CONSTRUCTIONAL REQUIREMENTS
13.1
Meters shall be designed and constructed in such a way so as to avoid intorducing any
danger during use and under normal conditions. The requirements of Section-I and IS14697 for indoor meters shall apply. In addition, following requirements shall be met:
a) Personal safety against electric shock
b) Personal safety against effects of excessive temperature.
c) Protection against spread of fire.
d) Protection against penetration of solid objects, dust & water.
e) Protection against fraud.
f) Protection against pilferage.
g) Meter base and meter cover should be ultrasonically welded
h) Protection against meter jamming by spurious signal injection/high magnetic field
application.
13.2
The meter shall be designed with application specific integrated circuit (ASIC) and
shall be manufactured using SMT (Surface Mount Technology). Power supply and
voltage divider circuits manufacred with PTH technology shall be acceptable. PCB
shall be FR 4 grade. Assembly of electronic components shall be as per ANSI/IPC-A610 standard.Critical components like ASIC, Microcontrollers etc. shall be procured
from STACK or IECQ registered suppliers. All major components & sub-assembly
parts (CT, PT, RTC, LCD etc.) shall have batch & source identification. Assembly line
shall have provision for testing of sub-assembled cards. Assembly shall be done in ESD
(Electrostatic discharge) protected area. Assembled PCB’s shall be subjected to
functional test using computerised automatic test equipment.
Page 7 of 24
Technical Specifications for DT Metering 3-phase
13.3
All insulating material used in the construction of meters shall be non-hygroscopic,
non-ageing and of tested quality. All parts that are likely to develop corrosion shall be
effectively protected against corrosion during operating life by providing suitable
protective coating.
The meter shall have an operation indication device such as a blinking LED. The
operation indicator shall be visible from the front window and capable of being
monitored conveniently with suitable testing equipment.
13.4
The meter shall confirm to the degree of protection IP 51 as per IS 14697, but without
suction in the meter for indoor meters for protection against ingress of dust, moisture
and vermin’s. The test shall be carried as per IS 14697/IS 12063. The meters alongwith
CT, designed for outdoor mounting without enlosure, shall confirm to IP-54 category
as per IS 12063/IEC 62052-11. In this type of meters, secondary cable of distribution
transformer shall be directly passed through the meter for measurement.
13.5
The meter-base, meter cover, terminal block and ETBC shall be made of unbreakable,
high grade, UV resistant (to be tested as per ASTMG 53/26/23), fire resistant,
reinforced, non-flammable, polycarbonate or equivalent high grade engineering plastic.
The bidder/manufacturer shall inform the hardness, melting temperature & tensile
strength of the material & show necessary test certificates. Polycarbonate material for
meter cover meter case & terminal cover shall confirm to IS 11731 (FH-1 category) &
shall meet the requirement of heat deflection test as per ISO 75/IS 11731 Pt-2 for a
temperature of 125 deg.C & a pressure of 1.8 Mpa (Method-A) & glow wire test as per
IS 11000 Pt-2/Sec-1 (at 650 deg.C. for 30 S) or IEC 60695-2-12 & ball pressure test as
per IEC-60695-10-2.
13.6
In case meter top cover is not transparent, the meter cover shall have one window. The
window shall be of transparent, high-grade engineering plastic for easily reading all the
displayed values/parameters, nameplate details and observation of operation indicator.
The window shall be ultrasonically welded with the meter cover such that it cannot be
removed undamaged without breaking the meter cover seals.
13.7
The terminal block, the ETBC and the meter case shall ensure reasonable safety against
the spread of fire. They should not be ignited by thermal overload of live parts in
contact with them. ETBC shall also have provision for sealing. Terminal block shall
also be tested for glow wire test as per IS 14697/IS 11000 Pt-2 Sec-1 at 960 deg.C for
30Seconds.
13.8
The terminal block shall be made of high grade non-hygroscopic, fire retardant (as per
method FH-1 of IS 11731), low tracking, fire resistant, & UV stabilized, reinforced
poly-carbonate (not bakelite) or equivalent high grade engineering plastic which should
form an extension of the meter case and have terminal holes and shall be of sufficient
size to accommodate the insulation of the conductors, meeting the requirement of IS
14697/CBIP technical report-88/ISO 075-2 for a temperature of 135 deg.C & a
pressure of 1.8 Mpa (Method A).
13.9
The terminals shall have suitable construction with barriers and cover to provide firm
and safe connection of current and voltage leads of stranded copper conductors or
copper reducer type terminal ends (thimbles). Appropriate bi metallic lugs should be
Page 8 of 24
Technical Specifications for DT Metering 3-phase
provided, if required, with each meter for fixing of the conductor.
13.10 The manner of fixing the conductors to the terminal block shall ensure adequate and
durable contact such that there is no risk of loosening or undue heating. Screw
connections transmitting contact force and screw fixing which may be loosened and
tightened several times during the life of the meter shall be such that the risk of
corrosion resulting from contact with any other metal part is minimized. Electrical
connections shall be so designed that contact pressure is not transmitted through
insulating material of terminal block. The clearance and creepage distance shall
conform to relevant clauses of IS 14697.
13.11 The meter shall be compact in design. The entire construction shall be capable of
withstanding stresses likely to occur in actual service and rough handling during
transportation. The meter shall be convenient to transport and immune to shock and
vibration during transportation and handling.
Critical components like IC’s & micro-controllers shall be STACK or IECQ
approved. All major components & sub-assembly parts (LCD, LED electronic
components etc.) shall have batch & source identification. Fully assembled &
finished meter shall be subjected to burn-in test for 72 hrs. at 55 deg C under base
load (Ib) condition.
13.12 The meters found defective with in guaranteed period shall be replaced / repaired by
supplier free of cost with in one month of intimation.
13.13 The meter shall be provided with an inbuilt accurate quartz crystal based real time
clock and calendar. RTC shall be pre-programmed for 30 years. Maximum drift
shall not be more than + 300 Seconds per year in line with IS 14697.
Synchronisation of RTC shall be possible through CMRI.
13.14 The bidder will give soft copy as well as hard copy of all the software’s and
technical details, software’s pertaining to all meters and associated equipment
supplied by him.
13.15 RESISTANCE TO HEAT AND FIRE – Terminal block, terminal cover & meter
case shall be tested as per IS 14697/IS 11000.
13.16 A test out-put shall be provided on the front panel in the form of LED, which shall
give out visible light pulses in proportion to the energy being measured by the
meter. This shall enable external reference equipment to verify the metrological
accuracy of the payment meter.
13.17 Meter Sl. No. shall be programmed in the meter memory & shall be communicated
to CMRI while downloading data.
13.18 The terminal arrangement shall be in sequence: Ir(in), Vr, Ir(out), Iy(in), Vy,
Iy(out), Ib(in), Vb, Ib(out), In(in), In(out). In case of meters with integral CT, phase
markings shall be provided.
14.0
ABNORMALITY OF EVENTS
Page 9 of 24
Technical Specifications for DT Metering 3-phase
The meter should have features to detect the occurrence and restoration of at least
the following abnormalities:
a)
Phase
reversal
sequence
The meter shall keep working accurately
irrespective of the phase sequence of the
supply.
b) External magnetic
influence
The metering system shall be provided with
adequate magnetic shielding so that any
external magnetic field (AC Electro Magnet
or DC Magnet) as per the values specified in
IS 14697/CBIP Technical Report No.88
(with latest amendments) applied on the
metering system shall not affect the proper
functioning and recording of energy as per
error limits prescribed by CBIP.
c) Missing Potential &
Potential
imbalance
The meter shall be capable of detecting and
recording phase wise occurrence and
restoration with date and time in the cases of
Potential failure (one phase or two phases)
even at zero current. All potential missing
cases shall be considered as power failure.
Meter shall also detect and log cases of
voltage unbalance (from 5 % for more than 5
minutes or more- programmable), not when
missing potential exists.
d) Current imbalance
The meter shall be capable of detecting and
recording occurrence and restoration with
date and time of Current unbalance (30% or
more for more than 15 minutesprogrammable).
e)
Meter shall record correctly in forward
direction with any one, two or all three
phases CT’s reversed.
Reversal
polarity
of
CT
CT open shall also be recorded.
f) Power on/off
The meter shall be capable to record power
on /off events in the meter memory. All
potential failure should record as power off
event.
The meter shall record the total duration of the above abnormalities, time and date
of their occurrences & restorations with snapshots of electrical conditions viz.
Voltage, current, PF etc
Page 10 of 24
Technical Specifications for DT Metering 3-phase
The meter shall keep records for the minimum last 100 events (occurrence +
restoration) for above abnormal conditions. It shall be possible to retrieve the
abnormal event data along-with all related snap- shot data locally using a hand held
unit (HHU) through the meter's optical port or through remote data interrogation
using remote communication interface & same can be viewed / analysed at Base
computer/DMC in simple and easily understandable format.
The threshold values for voltage, current and P.F. etc., for the purpose of logging
occurrence and restoration of various types of tamper will be mutually decided by
the purchaser and supplier. The supplier should, however, propose these values in
their offer.
14.3
ABNORMALITY/ TAMPER LOGIC
Properly defined meter abnormality/tamper logic should be provided. The logic
should be capable of discriminating the system abnormalities from source side and
load side and it should not log/record tamper due to source side abnormalities.
The persistence time for logging /registration of an occurrence & restoration of a
tamper should be 5 minutes.
15.0
MAXIMUM DEMAND REGISTRATION
The meter shall continuously monitor and calculate the average demand in kW,
kVAR/kVA during the integration period of 30 minutes and the maximum, out of
these in a month, shall be stored along with the date and time when it occurred in
the meter memory. The maximum registered value shall also be made available on
meter display. Whenever MD is reset, the maximum MD value shall be stored with
date & time tagging.
16.0
MAXIMUM DEMAND RESET
Facility for auto reset of MD at 00.00 hrs of first of every month or as decided by
the utility shall be provided for which minimum 30 years calendar shall be
programmed by the manufacturer. The meter shall display the maximum demand
reset count. Manual resetting of MD shall also be possible through CMRI.
17.0
SELF DIAGNOSTIC FEATURE
The meter shall be capable of performing complete self-diagnostic check to monitor
the circuits for any malfunctioning to ensure integrity of data memory location at all
time.
The
meter
shall
have
indication
for
unsatisfactory/nonfunctioning/malfunctioning of the following:
a) Time and date on meter display.
b) All display segments on meter display.
c) Real Time Clock (RTC) status in meter reading prints out at the computer in
Management Information Centre.
d) Non-volatile Memory (NVM) status in meter reading prints out at the computer in
Management Information Centre.
18.0
For meters to be installed outdoor -
Page 11 of 24
Technical Specifications for DT Metering 3-phase
Following requirement of temperature shall be met, for meters to be installed outdoor
without enclosure, in line with IEC 62052-11.
Specified Operating reange
-250C to 550C
Limit range of operation
-400C to 700C
Limit range ofstorage & transport
-400C to 700C
The meter shall withstand solar radiation & confirm to degree of protection IP-54 in
accordance to the requirement of cl. 6.3.4 & 5.9 of IEC 62052-11. Solar radiation test
shall be carried out in accordance with IEC 60068-2-5, under following conditins :

Meter in non-operating condition

Test procedure A (8 h irradiation & 16 h darkness)

Upper temperature +550C

Duration – 3 cycles or 3 days
After the test appearance & legibility of markings shall not be altered and the function
of the meter shall not be impaired.
19.0
ELECTRICAL REQUIREMENTS
19.1 INFLUENCE OF SUPPLY VOLTAGE
The meter shall meet the requirements of IS 14697.
19.1.1 VOLTAGE RANGE
Meters shall comply with the following requirements.
Specified operating range
From 0.8 to 1.1 Vref
Limit range of operation
From 0.7 to 1.2 Vref
Withstand range
From 0.0 to 1.9 Vref
19.1.1.1SPECIFIED OPERATING RANGE
This is the range of supply voltage forming part of the meter’s rated operating conditions
for metrological purposes, with specified limits of variation in percentage error with
supply voltage.
19.1.1.2LIMIT RANGE OF OPERATION WITH SUPPLY VOLTAGE
Outside the specified operating range of supply voltage but within the limit range of
operation (i.e. from 0.7 to 0.8 & 1.1 to 1.2 Vref) and when the ambient temperature
is within the specified operating range the requirements of IS 14697 shall apply.
The status of all registers, values, and parameters associated with the meter accounting
process shall continue to be valid and free of corruption. Any internal timekeeping
facility shall continue to maintain timekeeping until the support period applicable to
any operational reserve has elapsed.
Page 12 of 24
Technical Specifications for DT Metering 3-phase
The display need not operate, or is permitted to operate erratically. Correct operation of
all aspects of the meter shall resume when the supply voltage has returned to within
the specified operating range. However where the meter is fitted with a real-time clock
and the supply voltage is below 0.8 Vref for a time period longer than the operational
reserve, then it is permissible that the time may need to be reset.
19.1.1.3WITHSTAND RANGE
Outside the limit range of operation but within the supply voltage withstand range
(i.e. 0.0 to 0.7 Vref & from 1.2 to 1.9 Vref) the meter may sustain permanent damage and
degradation to its metrological and functional characteristics but this shall not give rise
to a safety hazard (e.g. exposure of live conductors, fire, explosion, or undesirable
restoration of the supply) & security of stored data in permanent memory (energy
consumption, record & programs) for retrieval later.
19.1.1.4 The meter shall meet the requirements of IS 14697 for Influence of self heating,
Influence of heating & Insulation.
19.1.2 VOLTAGE
DIPS,
OVERCURRENT
SHORT
INTERRUPTIONS
&
SHORT
TIME
Voltage dips, short interruptions & short time overcurrent shall not produce any loss or
corruption of data in the meter. The meter shall meet the requirements of IS 14697.
19.1.3 ABNORMAL PHASE CONDITIONS
For three-phase four-wire types, the meter shall withstand, without a safety hazard
arising, the maximum withstand voltage (1,9 Vref) applied to any two phases and
neutral with a phase angle of 60 deg. between the two phase voltages. The maximum
withstand voltage shall be applied for a period of 4 h together with a current of 50% of
Imax and unity power factor in each of the two phases under test. A total of three test
runs is required to cover the pairs of phases, with a cooling period of 1 h between each
run. This supply voltage withstand requirement does not apply to three-phase threewire direct-connected meters.
For all polyphase types, the meter shall continue to operate with any combination of
one or more phases with neutral remaining connected or any two phases without
neutral remaining connected and supplying power when the supply voltage is within
the specified operating range. Any internal timekeeping facility shall continue to
maintain timekeeping under these conditions.
19.2
POWER CONSUMPTION.
The measurement of power consumption in the voltage and current circuits shall be
determined as given in IS-14697.
19.4
ELECTROMAGNETIC COMPATIBILITY (EMC)
The requirements given in IS-14697/CBIP Report no. 88 shall apply subject to the
following clarifications and augmentations:
19.4.1 GENERAL TEST CONDITIONS
Any time-based charging shall be set to zero for the duration of these tests. Any internal
Page 13 of 24
Technical Specifications for DT Metering 3-phase
time keeping facility shall continue to operate during these tests.
19.4.2 TEST OF IMMUNITY TO ELECTROSTATIC DISCHARGES
After the application of ESD testing, the meter shall revert to normal function and
performance within a period of 1 min, without any external intervention.
19.4.3 TEST OF IMMUNITY TO RADIATED RF ELECTROMAGNETIC FIELDS
The test shall be conducted inline with clause 7.5.3 of IEC 62052-11 and IS 14697.
After the application of this test, the meter shall revert to normal function and
performance within a period of 1 min, without any external intervention.
19.4.4 TEST OF IMMUNITY TO ELECTRICAL FAST TRANSIENTS/BURSTS
The test shall be carried out first with the test load and limits of variation in percentage
error as given in IS-14697.
No change of the actual operating state or stored data is allowed. The meter shall
continue to operate correctly after the test without any external intervention.
19.4.5 TEST OF IMMUNITY TO CONDUCTEDDISTURBANCES, INDUCED BY RF
FIELDS
The requirements given in clause 7.5.5 of IEC 62052-11 and clause 8.2 of IEC 6205321 shall apply together with the following:
The test shall be carried out first for the test load and limits of variation in percentage
error. During the test, the normal behaviour of the meter shall not be disturbed.
No change of the actual operating state or stored data is allowed. The meter shall
continue to operate correctly after the test without any external intervention.
19.4.6 SURGE IMMUNITY TEST
The requirements given in 7.5.6 of IEC 62052-11 shall apply together with the
following:
After the application of this test the payment meter shall revert tonormal function and
performance within a period of 1 min, without any external intervention.
19.4.7 RADIO INTERFERENCE SUPPRESSION
The requirements given in IS 14697/7.5.8 of IEC 62052-11 shall apply.
19.4.8 INFLUENCE OF HARMONICS
The meter shall meet the requirements of cl.8.2 of IEC 62053-21.
20.0
TESTING REQUIREMENTS OF METER
20.1
EFFECT OF POWER OUTAGES
In the event of a power system outage interrupting the power supply to the meter there
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Technical Specifications for DT Metering 3-phase
shall be no malfunction in the operation of the meter accounting process. All registers
shall retain their values prior to the power outage.
20.2
CORE FUNCTIONAL TESTS WITHIN VOLTAGE AND TEMPERATURE
RANGE LIMITS
The core functions of the meter shall also be tested and requirements shall be met
under each of the following conditions:

Lower and upper limits of the specified operating temperature range

Lower and upper limits of the specified operating voltage range

The test sequence is therefore carried out four times under these conditions:

Lower temperature limit + lower voltage limit

Lower temperature limit + upper voltage limit

Upper temperature limit + lower voltage limit

Upper temperature limit + upper voltage limit
21.0 FIXING OF METERS
Every meter should have three fixing holes, one at top & two at bottom. The top
hole shall be provided with a special clip at the back of the meter so that the holding
screw is not accessible after the fixing of meters. The lower fixing screw shall be
provided under the sealed terminal cover. The requisite screws shall be supplied
with each meter.
22.0 OTHER SALIENT FEATURES OF METERS
It should be possible to check the healthiness of phase voltages by displaying all the
voltages on the meter display.
The meter should work accurately irrespective of phase sequence of the supply.
The meter should remain powered up and functional even when either of the two phases
or one phase along with neutral is available to meter.
23.0 TESTS
The manufacturer shall have in his works, fully automatic meter testing equipment
meeting the requirements of IS 12346 for factory calibration of meters. Only type tested meters shall be offered. Detailed type-test report from NABL accredited
laboratory shall be submitted along-with the bid and the same should not be more
than 36 months old at the time of submission of bid. Make and type of major
components used and GA drawing of the type-tested meter shall form a part of the
type-test reports. In case there is any change in make/type of major components, the
type tests shall be repeated without any cost to the owner. Owner shall reserve the
right to select meters at random from the lot offered and get the meter type-tested at
any NABL accredited laboratory. The supplier shall have no right to contest about
the test-results of the NABL accredited lab and shall replace/take corrective action
without any cost implication to the owner. Unless specifically waived off, all tests
shall be witnessed by the purchaser.
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Technical Specifications for DT Metering 3-phase
a) Type Tests:
Requirement of type-tests shall be in line with Table 16 of IS
14697. One (1) out of every thousand (1000) meters or part of 1000 meters per lot
shall be subjected to the complete range of type tests prescribed in standards indicated
in clause 2.0 above, at any of the NABL accredited test laboratories, after final
assembly. No extra charges shall be payable to the supplier for carrying-out these
type-tests. In case of any failure to pass all specified tests, the bidder shall arrange to
carry out the requisite modifications/replacements in the entire lot of meters at his own
cost. After any such modifications and final assembly, two (2) meters selected out of
the lot by the Owner's representative shall be subjected to the full range of type tests.
The Owner shall accept the lot only after successful type testing.
The meters used for type testing shall be separately identified, duly marked, and
supplied to the Owner in case they are fully functional and as good as other (new)
meters, after necessary touching up/refurbishing. In case this is not possible, the
bidder shall provide their replacements at no extra cost to Owner.
The manufacturer shall arrange all type testing specified above, and bear all
expenses for the same.
For RTC, test report of RTC manufacturer shall be acceptable.
testing requirements shall be as per IS 14697, & IEC 62053-21.
For energy meter, the
Note:-Validation of software may be taken-up as per agreement between owner &
manufacturer for the vending system & MIS.
b) Acceptance Test: All acceptance tests as stipulated in Table 16 of IS-14697 shall be
carried out by the supplier in the presence of the purchaser’s representative.
c) Routine Tests: All routine tests as stipulated in Table 16 of IS-14697 shall be
carried out and routine test-certificates/reports shall be submitted to the purchaser for
approval.
24.0 MARKING OF THE METER
The marking on every meter shall be in accordance with relevant clauses of IS 14697.
Every meter shall have nameplate beneath the meter cover such that the nameplate
cannot be accessed without opening the meter cover and without breaking the seals of
the meter cover and the nameplate shall be marked distinctly and indelibly. The basic
marking on the meter nameplate shall be as follows:
a) Name of Project (Details to be given later)
b) Manufacturer’s name, trade mark & Place of manufacture
c) Type Designation
d) No. of phases & wires
e) Serial number
f) Year of manufacture
Guaranteed upto ……………………..
g) Reference Voltage
h) Rated Current
i) Principal unit(s) of measurement
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Technical Specifications for DT Metering 3-phase
Meter Constant (imp/kWh)
Accuracy class - kWh
- kVARh
k) Repeatability error as per IS
l) “Property of ………….”
m) Purchase Order No. & Date
The manufacturer shall emboss manufacturer’s name/Brand on meter base & cover
alongwith grade of material used.
Where the meter contains an integral battery the battery symbol and chemical symbol
(e.g. Li = lithium) shall be marked on the meter.
25.0 SEALING OF METER
Reliable sealing arrangement should be provided to make the meter tamper resistant
and to avoid fiddling or tampering by unauthorized persons. For this, at least two (2)
nos. seals on meter body, one (1) No. of seals on meter terminal cover and one (1) No.
seal on each communication ports shall be provided. All the seals shall be provided in
front side only. Rear side sealing arrangement will not be acceptable. The requrement
of sealing shall be in line with IS 15707.
26.0 OUTPUT DEVICE
The meter shall have a test output accessible from the front and be capable of being
monitored with suitable testing equipment while in operation at site. The operation
indicator must be visible from the front. Optical test output device shall be provided
in the form of one common LED / LCD output device for kWh. The requirement of
the optical test output shall meet the requirement of IS 14697/ cl.5.11 of IEC62052 11. The manufacturer shall state the min. no. of pulse counts necessary to ensure
measurement accuracy at least 1/10 th of the specified error limits at various points
& consistent with desired resolution. The resolution of test output shall be sufficient
to conduct accuracy test at the lowest load in less than 5 minutes & starting current
test in less than 10 minutes.
27.0 INSTALLATION AND COMMISSIONING
The static energy meters specified above shall be installed at locations to be
specified by the owner.
The Bidder shall be responsible for total installation and commissioning of the
meters (along with test blocks, if supplied separately) as per Owner's advice,
including unpacking and inspection on receipt at site, mounting the meters,
connection of input& output cables to the meters including any required rewiring,
functional testing, commissioning and handing over. The Bidder's personnel shall
procure/carry the necessary tools, equipment, materials and consumables (including
insulated wires, lugs, ferrules, hardware etc.).
As a part of commissioning of CMRI the Bidder shall load the software specified in
this specification into the PCs at the Base computer stations, and fully commission
the total meter reading scheme. He shall also impart the necessary training to Utility
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Technical Specifications for DT Metering 3-phase
engineers.
Following technical information shall be furnished by the Bidders in their offers:
i) Dimensions of proposed meter.
ii) Weight of proposed meter.
iii) Dimensions of CMRI
iv) Weight of CMRI
v) Details of Meter testing equipment proposed to be made available at site for
commissioning.
vi) Dimensions and weight of the test block, if supplied separately.
28.0 QUALITY ASSURANCE PLAN
28.1 The vendor shall furnish the following information along with his bid; failing which
the bid shall be liable for rejection. Information shall be separately given for
individual type of material offered.
i) The structure of Organization
ii) The duties and representatives assigned to staff ensuring Quality of work
iii) The system of purchasing, taking delivery and verification of materials
iv) The system for ensuring quality of workmanship
v) The quality assurance arrangements shall conform to the relevant requirement of
ISO 9001 or ISO 9002 as applicable
vi) Statement giving list of important raw materials/components, list of sub-suppliers,
list of standards according to which the raw materials are tested. List of test normally
carried out on raw materials in presence of vendor’s representative, copies of test
certificates.
vii) Information and copies of test certificates in respect of bought out accessories.
viii) List of manufacturing facilities available.
ix) Level of automation achieved and list of areas where manual process exists.
x) List of areas in manufacturing process, where stage inspections are normally carried
out for quality control and details of such tests and inspections.
xi) Lists of testing equipment available with the bidder for final testing of equipment
specified and test plant limitation if any, vis-à-vis the type, special acceptance and
routine tests specified in the relevant standards. These limitations shall be very clearly
brought out in schedule of deviations from specified test requirements.
28.2
Manufacturing & testing facilities
The following manufacturing & testing facilities shall be available at the works :

Assembly lines shall be completely dust proof

Testing areas shall be temperature & humidity controlled

Testing & calibration equipment shall be automatic with valid calibration
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Technical Specifications for DT Metering 3-phase
certificates
28.3

Power supplies for testing shall be distortion free with sinusoidal waveforms
& maintaining constant voltage, current & frequency as per requirement

Batch testing facility on automatic computerized test bench shall be
available directly producing printouts for the test results.
The vendor shall also submit following information after award of contract :
i) Sub-suppliers of raw materials as well as bought out accessories & components shall
be selected from those furnished along with offers.
ii) Type test certificates of the raw materials and bought out accessories as required by
the utility.
iii) Manufacturing Quality Plan (MQP) shall be submitted along-with the bid. The
purchaser hold points for stage inspection shall be discussed between the purchaser and
vendor at the time of award of contract before the MQP is finalized.
29.0 GUARANTEE
Manufacturer shall undertake a guarantee to replace the meters up-to a period of 60
months from the date of installation, which are found defective/inoperative within
the guarantee period. These defective/inoperative meters shall be replaced within
one month of receipt of report for such defective/inoperative meters.
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Technical Specifications for DT Metering 3-phase
SECTION - II
MIS REPORTING
1.0
SCOPE
This section specifies the requirements of MIS reporting to be provided for the
metering system.
A client system will be provided in the project monitoring center to produce the MIS
reports.
1.1
HARDWARE REQUIREMENTS
The bidder will specify the configuration of hardware used for establishing the MIS.
1.2
SOFTWARES
Licensed copies of the following software shall be made available. Necessary softwares
shall be installed on each common meter reading instrument (CMRI) (where
applicable) and Base computer software (BCS) by the supplier.
Common Meter Reading Instrument (CMRI) would be user-friendly for reading,
downloading meter data.
Windows based user interactive Base Computer Software (BCS) (for Data Monitoring
Centre) for receiving data from CMRI/main server and downloading instructions from
base computer software to CMRI/main server. This BCS should have, amongst other
requirements, the facility to convert meter reading data into user definable DBF
(Access) and spreadsheet format for integrating with the purchaser's billing system.
Here again an "Export wizard" or similar utility shall be available whereby user can
select file format, what data to export, the field width selection so that it may be
possible for the user to integrate the same with the user’s billing data and process the
selected data in desired manner.
Necessary software for loading application program into meter via CMRI serial port
shall be provided.
The software’s shall have the flexibility to generate Load survey reports & Tamper
reports.
Load survey reports: Load survey report for a pre determined time i.e. from ________
date to ___________ date, shall include the following:
Equipment ID, meter number, Connectivity references i.e. identity & location of pole /
Distribution transformer reference, feeder reference, sub-division reference, division
reference, circle reference, time, date, maximum demand ( kW) , kWh, power factor,
MD reset count, power on hours, outage duration, number of outages, Voltages max
R,Y,B date time and duration, Voltages minimum R,Y,B date time and duration, load
factor as (energy consumed/(maximum demand x power on hours)), average load as
(energy consumed / power on hours).
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Technical Specifications for DT Metering 3-phase
Load survey data should be available in the form of bar charts as well as in
spreadsheets. The BCS shall have the facility to give complete load survey data both in
numeric and graphic form.
It shall be possible to analyse the following :

if DT is overloaded alongwith its duration –
o Peakloading in kVA


Phasewise instantaneous value in each half hour beyond certain limit

Phasewise average half hour value alongwith its duration beyond certain
limit

Values of kW & kVAR for each half hour period shall be logged phase
wise.

With this data loading profile of DT shall be plotted. MIS reports
showing individual DT wise overloading, neutral current above 10% of
rated current, DT loaded less than 25% of rating shall be possible
through the software supplied.
if DT has unbalanced loading –
o Phase wise currents shall be logged/plotted for each half hour interval.
o Phase wise unbalance (in %) shall be obtained for each phase by summating the
weighted unbalance for each half hour period.

neutral current for 3 phase DT – The software shall show the magnitude of neutral
current for each half hour interval.

Minimum & maximum reactive power flow for each half hour interval for planning
installation of capacitors – Base & peak capacitor requirement for each DT shall be
calculated based on the kVAR data logged.

No. & hours of supply interruption

Occurances of fuse failure on HT side of DT – Voltage data shall be used to produce
information on reliability of power supply.

Nos. of LT faults DT has been subjected to alongwith identification of phase & type of
fault - Voltage data shall be used to produce information on no. of LT faults. By
analysing the phase curent, power factor etc., it shall be possible to indicate the type of
fault in LT system.
BCS shall be customized according to the owner’s requirement.
----------
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Technical Specifications for DT Metering 3-phase
GUARANTEED TECHNICAL PARTICULARS
FOR THREE PHASE DT METERS
S.No.
DESCRIPTION
1.
Maker’s Name & Place
2.
Type of meter/Model
3.
Standards to which the meter
conform
4.
Accuracy Class
kW
kVA
5.
Parameters measured
6.
Power Factor Range
7.
Overload Capacity
8.
Variation of voltage at which
meter functions normally
9.
Minimum Starting current
10.
Dynamic Range
11.
MD Reset provisions
12.
Display of cumulative MD
13.
Reset count
14.
No. of digits of display and
height of character
15.
Particulars of readout by CMRI
including time required for
download of data
16.
Meter terminal block having
sealable extended terminal over
17.
Non volatile memory retention
time in absence of power
18.
Memory capacity (kB)
19.
Details of ratings/capacities
(a)
Current ratings (-5A)
(b)
Integration period 30 minutes
20.
Power consumption per phase
(a)
Voltage circuit
(b)
Current circuit
Page 22 of 24
Technical Specifications for DT Metering 3-phase
21.
Details of tamper & fraud
provisions
(a)
On display
(b)
With CMRI and data transfer
22.
Sealing of the meter (No. of
seals)
(a)
Meter cover
(b)
Terminal block cover
(c )
MD reset push button
(d)
Communication port
(e)
Others if any
23.
Whether meter carries any
certification mark (like BIS)
24.
Self diagnostics features if any,
provide details
The meter offered by us will indicate unsatisfactory/non-functioning of
the following:
i)
Time and Calendar
ii)
Real Time Clock (RTC) battery
iii)
All display segments
iv)
Non- volatile memory
Meter has the capability of checking its circuits for any malfunctioning.
Also the meter checks itself once during the day at 00.00 hrs.,
immediately after restoration of power (after power outage) and each
time the meter is powered up.
Verifies configuration date

Detect low battery voltage

Checks microprocessor functions

Detects unexpected micro processor resets.
25.
Principle of operation (provide details)
26.
Protection from lightning &
heavy voltage surge
27.
Protection from Heavy short
circuits
28.
Total weight of the meters
29.
Temperature range for safe
operation
Page 23 of 24
Technical Specifications for DT Metering 3-phase
30
Material & colour
a)
Case
b)
Extended cover to cover entire
terminals effectively
c)
Material of mainframe
d)
Material of cover to gasket
Page 24 of 24