TECHNICAL SPECIFICATION FOR FULLY STATIC ENERGY METERS FOR
DISTRIBUTION TRANSFORMER METERING
1.0 APPLICATION
STATIC ENERGY METER FOR MEASUIRNG
ALTEERNATING CURRENT ELECTRICAL ACTIVE,
REACTIVE AND ENERGY IN BALANCED AND
UNBALANCED
LOADS
DISTRIBUTION
TRANSFORMER ‘L.T.’ SIDES METERING FOR
ENERGY ACCOUNTING
2.0
STANDARDS TO IS-14697 (1999) Specification for AC Static Transformer
WHICH METER SHALL operated Watt Hour & VAR-Hour meters, class 0.5S IEC
COMPLY
61000-4-5& 6 for Electro Magnetic Compatibility-Testing
and Measurement techniques, Surge immunity test;
ANSI/IPC-A-610
Workmanship
standard
for
Acceptability of Electronic Assemblies ( A standard
development by institute for Interconnecting and
Packaging Circuits);
All additional requirements as specified in ANNEX ‘G’ of
IS 14697 shall be provided in all meters supplied.
The equipment meeting with the requirements of other
authoritative standards, which ensure equal or better
quality than the standard mentioned above, also shall be
considered; in case of conflict the order of precedence
shall be (I) IS-14697(2) IEC-60687; Other relevant
Standards. In case of any difference between provisions
of these standards and provision of this specification,
provisions contained this specification shall prevail.
3.0
LOCTION AND OUTDOOR TYPE
MOUNTING
Direct Sunrays shall be falling on the LT DB and Energy
Meter to withstand temperature inside enclosed box.
4.0 GENERAL TECHNICAL REQUIREMENT
4.1 TYPE
STATIC ENERGY METER, 3 PH, 4 WIRE LT CT
OPERATED TRI-VECTOR ENERGY METER, LOAD
PROFILE DATA RECORD, ‘MD’ REGISTER, ‘TOD’
REGISTER – SUITABLE FOR BOTH UNBALANCED
& BALANCED LOAD.
4.2 FREQUENCY RANGE
4.3 Accuracy Class
4.4
REFERENCE
SECONDARY
VOLTAGE
4.5 Voltage Variation
50Hz +/- 5%
0.5 S
Suitable for operation From 415 Volts Ph-Ph/or 240m
Volts Ph-N.
(As per IS-14697) with variation (-) 40% to (+) 20%
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4.6 Basic Current (Ib)
5-15 Amps. (as per adopted CT Ratio on LT side of
Distribution Transformer).
4.7 Maximum Continuous 2 Ib
Current.
Starting and Short time current shall be as per IS 14697.
4.8.1 DESIGN
Meter shall be designed with application specific
integrated circuit (ASIC) for micro controller; shall have
no moving part, electronic components shall be assembled
on printed circuit board using surface mounting
technology
(SMT); factory calibration using high
accuracy (0.1 class) software based test bench.
Assembly of electronic components shall be as per
ANSI/IPC-A-610 standard. Internal power supply circuit
shall be designed using highly reliable component.
Critical components such as metering ICs (ASIC), Micro
controller etc. shall be STACK and IECQ approved.
Current Transformer shall be used for ‘Phase’ and
‘Neutral’ circuit to achieve isolation against external
interference / electrical spikes.
Meters shall be manufactured using latest and ‘state of the
art’ technology and methods prevalent in electronics
industry.
4.8.2 MANUFACTURING All inward flow of major components and sub assembly
PROCESS, ASSEMBLY
parts (CT, PT, RTCs/Crystal, LCDs, LEDs, power circuit
electronic components etc.) shall have batch and source
identification.
Multiplayer ‘PCB’ assembly with ‘PTH’ (Plated through
Hole) using surface mounted component shall have
adequate track clearance for power circuits. SMT
component shall be assembled using automatic ‘pick-andplace’ machines with in process 7 stages, Reflow
Soldering oven, for stabilized setting of the components
on ‘PCB’.
For soldered PCBs, cleaning and washing of cards, after
wave soldering process is to be carried out as a standard
practice.
Assembly line of the manufacturing system shall have
provision for testing of sub-assembled cards.
Manual placing of components and soldering, to be
minimized to items, which cannot be handled by
automatic machine.
Handling of ‘PCB’ with ICs/C-MOS components, to be
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restricted to bare minimum and precautions to prevent
‘ESD’ failure to be provided.
Complete assembled and soldered PCB should under go
functional testing using computerized Automatic Test
Equipment.
Test points should be provided to check the performance
of each block/stage of the meter circuitry.
Fully assembled and finished meter shall under go ‘burnin’ test process for 24 Hours at 55 degree Celsius (Max
temperature to not exceed 60 degree Celsius) under base
current (Ib) load condition.
Testing at intermediate and final stage to be carried out
with testing instruments, duly calibrated with reference
standard, with traceability of source and date.
4.9 DISPLAYS
LCD shall be suitable for temperature withstand of 70◦C.
7 Digit, backlit Liquid Crystal Display (LCD) of
minimum 10mm X 5mm height, wide viewing angle.
Auto display cycling push button required with
persistence time of 12 seconds, Sequence of display of
various instantaneous electrical parameters shall be as per
Nigam’s Requirement at the time of order.
4.10
Performance under As per IS-14697
Influence Quantities.
The offered meter shall be designed and protected such
that no external effects and influences would change its
performance & shall work satisfactorily within guaranteed
accuracy limits, as specified in IS 14697,under the
presence of influence quantities.
4.11
ADDITIONAL
i)
Energy meter shall have test output, accessible
TECHNICAL FEATURES
from the front, and be capable of being
monitored with suitable testing equipment
4.11.1 OUTPUT DEVICE
while in operation at site.
ii)
Operation indicator must be visible from the
front.
iii)
Test output device shall be provided in the
form of LED/LCD.
iv)
Resolution of the test output device shall be
sufficient to enable the starting current test in
less than 10 minutes. Nameplate shall indicate
the ‘impulse/Unit’ with appropriate resolution.
4.11.2
CUMULATIVE
Meter should have provision for automatic recording
ENERGY REGISTER
of cumulative KWH & MD KW at say 24.00 hours on
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the last day of the month for each of the past six
calendar months and same to be stored in the
register/memory.
4.12
TEMPERATURE As per IS 14697 except that the meters shall be suitable
CONDITIONS
for satisfactory operation inside the enclosure with
ambient temperature as above outside the enclosure. The
enclosure is subjected to direct solar radiation in service
and components shall be selected considering this aspect
also.
4.13 REAL TIME CLOCK RTC shall be pre-programmed for 30 years Day/Date
(RTC)
without any necessity for correction. Maximum drift shall
not exceed +/- 300 Seconds per year.
Time & date setting shall only be possible through one of
the following:
(a) Common Meter Reading Instrument (CMR) or
Meter testing work bench and this shall need
password enabling.
(b) From Base billing system computer through
communication network for network connected
meters.
RTC CLOCK DAY/DATE Synchronization of Energy Meter ‘RTC’
SYNCHRONISATION
a) Thru ‘CMRI’ with password protection.
b) From Base billing system computer through
communication network for network (LAN/WAN)
connected meters.
Synchronization shall be carried only if the ‘RTC’ drift is
within +/- 10 minutes.
Error log to be recorder by the system S/W if the ‘RTC’
time is out of range with respect to external time
reference.
4.14
QUANTITIES TO
BE
MEASURED
&
DISPLAYED
i)
ii)
iii)
iv)
v)
vi)
Internal diagnostics
The following parameters
shall be
displayed continuously on Auto Scroll.
a)
Date
b)
Real Time
c)
Active energy (KWH).
d)
Reactive Energy (KVARH)
e)
Apparent Energy (KVAH)
Maximum demand (KW/KVA)
MD Reset Count (Nos.)
Instant Power Factor ( Lead/ Lag)
Instantaneous phase wise voltage
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vii)
viii)
ix)
Instantaneous phase wise current.
Instantaneous
Demand
KW/KVA
phasewise
Cumulative power –ON hours.
4.15
TIME OF DAY 6 different TOD energy registers as per clause G-8 of IS
(TOD) REGISTERS
14697 are required. Time block settings shall be advised
to the supplier at least 4 weeks before commencing
delivery.
Change of time slots for ‘TOD’ metering, shall be with
‘password’ enabling, from CMRI or from base computer
for network (LAN/WAN) operated meters.
4.15
MAXIMUM
DEMAND
INTERGRATION PERIOD
i)Energy Meter shall continuously monitor and
calculate the average maximum demand for each
demand interval time of 30 minutes and maximum of
these in a calendar month shall be stored along with
date and time when it occurred;
ii)It shall, however, be possible to change the demand
integration period (DIP); from 30 to 15 minutes at site,
with proper security;
iii)The Maximum demand of past six months shall be
stored in the memory with date and time.
iv)It shall be possible to retrieve this data through
communication port and CMRI.
v) There shall be no resetting button for MDI data and
resetting shall be possible, on request, via CMRI
connection with password enabled access only.
4.16 LOAD SURVE DATE Storage in Non volatile memory for 70 days, 30 minute
REGISTERS
demand of any of the flow parameters of KW, KVA,
KVAR (or Pf), Average of 3 voltages shall be provided.
4.17 INDICATIONS
Energy meter shall have test output, accessible from the
front and be capable of being monitored with suitable
testing equipment while in operation at site.
Resolution of the test output device shall be sufficient to
enable the starting current test in less than 10 minutes.
Nameplate shall indicate the ‘impulse/unit’ in appropriate
resolution.
4.18 COMMUNICATION Data architecture and communication protocols shall
FACILITIES
& enable easy multi-vendor exchange of data without usage
STANDARDS
of any converting / translating equipment. For this, the
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data structure adopted within the energy meter shall be on
an internationally acceptable method. The data structure /
coding details shall be furnished to the Owner. The media
copy of software, required for down loading the
information to a user friendly “Windows / LINUX” based
operating system, of owner’s billing computer system
(BCS), Substation data logger ‘PC’ system thro CMRI
shall be furnished in required number of copies (On CD)
without any additional cost to the Owner.
a)Local communication Port
The energy meter shall have a galvanically isolated
optical communication port or equivalent, located in front
of the meter for data transfer to or from a DOS based hand
held data Collection Device (Common Meter Reading
Instrument, CMRI-conforming to CBIP technical report111) with proper security and without error.
b) Remote communication facility:
Meters shall have separate RS-232 communication port
to interface standard modems for remote data interface
using any of the communication mediums such as RF
or GSM-GPRS. Power of radio frequency shall be
10mW equivalent to 100mts line of sight range.
If specified elsewhere, the meters shall have Transreceiver and associated modem for AMR, with any one
of the following mode of data communication
mediums:
(a) Radio Frequency (RF) communication
(b) GSM-GPRS communication
c) Data shall be provided for meter identity, meter
diagnostics and event diagnostics.
4.19
TAMPER AND 1 Phase
The meter shall keep working
FRAUD
PROTECTION
Sequence
accurately irrespective of the phase
FEATURES
Reversal
sequence or the supply.
CT’s Shorting The meter shall be capable of
and Polarity recording energy accurately even if
2 reversal.
the polarities of CT’s are reversed
or current terminals are inter
changed and the meter shall be
capable of detecting CT shorting /
opening to identify.
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3
Missing
Potentials
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Missing
Neutral
5
6
7
8
Anti Tamper
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Current
Imbalance
The meter shall be capable of
detecting and recording occurrence
of missing potential (One Phase or
two Phases) which can happen due
to
intentional
/
accidental
disconnection of Potential lead(s) (
One or two ), failure of phase line
fuse from the transformer primary
side. The meter should also be able
to detect and log cases of voltage
imbalance ( from 10% for more than
15 minutes or more- programmable).
The meter shall continue to record
accurately
for
balanced
and
unbalanced load even if the neutral
is
removed
/
disconnected
accidentally or incidentally.
The meter shall log and display
tamper of injecting current/voltage
through neutral.
Recording of tamper events should
have roll over facility.
Load survey for display for all the
parameters should be available for
70 days.
Meter should log on the events of
attempt of tempering by external
magnetic field as mentioned in the
CBIP- Technical Report-88 with
latest amendments.
The meter shall record at max.
current ( Imax) under the influence
of abnormal external magnetic field
irrespective of actual load. The
meter shall record as per actual load
once the external abnormal magnetic
field is removed. In such condition,
the meter shall log the event for
presence of abnormal external
magnetic field and its restoration.
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 minutes).
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10 Power ON / The meter shall be capable of record
OFF
power On/Off events in the meter
memory.
All potential failure
should be recorded as power Off
event.
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The meter shall record the above
abnormalities, time and date of their
occurrences and restorations with
snapshot of electrical conditions viz.
voltage current and power factor etc.
The meter shall keep records for the
minimum
last
200
events
(occurrence + restoration) for above
of abnormal conditions. It shall be
possible to retrieve the abnormal
event data along with all the related
snapshot data to the meter’s optical
port or through radio with the help
of a meter reading instrument and
down load the same to the BCS
where it shall be available for
viewing. How this information shall
be made available in simple and
easily understandable format.
The meter shall also be capable to
withstand and shall not get damaged
if phase to phase voltage is applied
between phases to neutral for short
duration.
The meter shall record the last duration date. Time and the
number of such occurrences. The number of such tamper
events shall not be less than 200. The meter should not
get damaged if line voltage is applied to neutral.
5.0 TYPE TESTS
5.1 For Basic Energy Meter
i) The meter offered should have successfully passed all
type tests described in the IS 14697 and IEC 61000 4-5
Type test certificate shall be submitted along with the
offer and the same shall not be more than 36 months old at
the time of submission of the bid.
ii) Further Nigam shall reserve the right to pick up energy
meters at random from the lots offered and get the meter
tested at third party lab i.e. CPRI Bangalore / agencies
listed at Appendix-C of CBIP 88 / NPL / CQAL / ERTL /
ERDA at the sole discretion of the Nigam. The supplier
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has no right to contest the test results of the third party lab
or for additional test and has to replace / take corrective
action at the cost of the supplier.
It shall be the responsibility of the supplier to arrange such
tests and Nigam shall be informed of the date and time of
conduction of tests well in advance to enable him to
witness such tests. Test charges of the testing authority,
for such successful repeat type tests, shall be reimbursed
at actual by the Owner.
5.2 For Data Transfer and This shall be on mutually agreed tests to be finalized at
Communication capability
the time of Contract Award. The meter could be tested at
third party lab i.e. CPRI Bangalore /NPL /ERTL / ERDA.
6.0
ACCEPTANCE & i) Criteria for selection for such tests and performance
ROUTINE TESTS
requirements shall be as per IS 14697.
ii) Additional acceptance shall include Surge withstand
(SWC), Lightning impulse and HF disturbance as per IEC
6100-4&5. For this, one sample meter per order shall be
subjected to SWC / other semi-destructive tests. Meters
after tests shall not be used. Lightning Impulse test, listed
under ‘SWC’ shall be done for 8 KVp and 300 Joules.
iii) Accuracy tests shall be performed at the beginning and
at the end of the acceptance tests specified.
7.0
ASSURANCE
QUALITY
The manufacturer shall have a comprehensive quality
assurance program at all stages of manufacture for
ensuring products giving reliable, trouble free
performance.
An indicative outline Quality Plan has been specified
in Annexure-I.
The Bidder shall furnish with HIS offer a
comprehensive Quality Plan covering all aspects of
the design, procurement, assembly, testing etc. for
Owners evaluation along with a detailed
manufacturing flow diagram. The QP shall also give
details of the quality control procedures,
documentation, certifications available / being
practiced by the Bidder and his major sub-suppliers.
Bidder shall furnish following information along with
his bid:
i) Organisation structure of the works with details of
‘QA’ set up in overall workflow;
ii) Copy of system manual showing ‘QAP’ (Quality
Assurance Plan) as actually practiced at works.
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iii) List of raw materials and critical components
(ASIC chip, crystal clock, memory register Chip,
transformers, optical ports etc..) with their suppliers;
iv) State inspection of product before final testing;
v) Procedure adopted for ‘In-situ’ testing of PCBs,
after replacement of surface mounted component, for
quantitative parameteric variation of tolerance by self
or sub-contractor.
vi) Testing and calibration facility with manpower
data of bench operators;
vii) Sample copies of test certificate of bought out
components.
viii) Quality plan to be adopted by the successful bidder
shall be reviewed and approved by the Owner during
contract award stage.
8.0 GUARANTEE
9.0
FIXING
CONNECTION
ARRANEMENT
Equipment (Meter) supplied shall be guaranteed for a
period of 60 months from the date of supply. Bidders
shall guarantee to repair or replace the meters and
meter boxes (if supplied), which are found to be
defective/ imperative at the time of installation, or
become inoperative / defective during guarantee
period. Replacements shall be effected within 1
month of receipt of defective material.
The bidder shall extend the guarantee of 5 years.
However, the back up bank guarantee provided by the
bidders shall be valid for 2 years only.
AND
Manufacturer shall ensure following technical points:
i)
Meter shall be suitable for mounting on
Distribution Box of LT (LTDB) side of
Distribution Transformer;
ii)
Mounting / Fixing arrangement drawing to
be properly co-ordinated to match with
LTDB.
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10.0
GENERAL AND a)
METER CASE:CONSTRUCTIONAL
REQUIREMENTS.
The meter case & cover will either be ultrasonically
welded or shall have push fit type arrangement with two
No. Aluminium seals, one each on either side, so that
Meter’s internal parts are only accessible after breaking
seals, ultrasonic welding, push fit arrangement or case /
cover of the meter and it should become unserviceable.
The material for base and transparent cover of the meter
shall be of thermoplastic / engineering plastic
respectively.
The meter shall be factory calibrated and shall have
unidirectional screws fully embedded so that these cannot
be unscrewed by means of pliers etc. for sealing.
The meter case shall have at least three mounting holes, 2
holes for mounting screws on the terminal block sealed
beneath the terminal cover and one for hanging screw on
the top.
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b)
TERMINALS AND TERMINAL BLOCK:-
The meter shall have brass terminals suitable for
termination of aluminum service cable. The terminal
block which shall be of high grade non-hygroscopic, low
tracking property insulating material (not Bakelite) which
should form and extension of the meter case and have
terminal holes of sufficient size to accommodate the
insulation of the conductors.
The manner of fixing the conductors to the terminals 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 screw into a metal nut. All parts of each
terminal shall be such that the risk of corrosion resulting
from contact with any other metal part is minimized. Two
screws shall be provided in each current terminal for
effectively clamping the external leads of thimbles. Each
clamping screw shall engage at least 3 threads in the
terminal. The ends of screws shall be such as not to
pierce the conductor.
Electrical connections shall be so designed that the
contact pressure is not transmitted through insulating
material. For current circuits, the voltage is considered to
be the same as for the related voltage circuit.
The internal diameter of terminal holes shall be
5.5mm(min.)
The clearances and creepage distances shall conforms to
clause 6.6 of IS : 13779/1993.
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c)
TERMINAL COVER:-
The terminal cover shall be extended type, which can be
sealed independently of the meter cover. The terminal
cover shall enclose the actual terminals, the conductor
fixing screws, the external conductors and their insulation
i.e. no part of meter of cables/accessories shall be visible
from the front of the meter.
When the meter is mounted, no access to the terminals
shall be possible without breaking the seal(s) of the meter
terminal cover.
The terminal cover shall have at least two sealing screws.
The fixing screws used on the terminal cover for fixing
and sealing shall be kept captive in the terminal cover.
d)
RESISTANCE TO HEAT AND FIRE:The terminal block, the terminal cover and the meter case
shall ensure reasonable safety against the spread of fire.
They should not be ignited by thermic over-load of live
parts in contact with them.
e)
PROTECION AGAINST PENETRATION OF
DUST & WATER:The meter shall conform to the degree of protection IP 51
against ingress of dust, moisture and vermin’s.
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f) ELECTRONIC COMPONENTS:
The meter shall be made from high accuracy and reliable
Surface Mount Technology (SMT) Components
g) DATA TRANSFER CAPABILITES:The meter shall have necessary facilities to transfer the
data via the Communication port the hand held data
collection device (DCD) and also to down-load this data
on a P.C. to get complete details in numeric form. The
necessary software for this purpose shall be provided by
the supplier.
h) FIXING ARRANGEMENT
Every meter shall have three fixing holes one at the top
and two at the bottom. The top hole shall be provided with
a special clip at the back of the meter so that holding
screw is not accessible to the consumer after the fixing of
the meters. The lower fixing screws shall be provided
under the sealed terminal cover.
i)
SEALING:
2 No. unidirectional sealing screw shall be provided for
proper fixing of meter cover with 2 No. aluminium seals
one each on either side so that meter internal parts are
only accessible after breaking the seals, ultrasonic
welding, push fit arrangement or case/cover of the meter.
Separate sealing arrangements shall be provided for MDI
reset and communication port.
In addition, the firm/supplier shall affix 3 Nos. good
quality numbered hologram on base and cover one on
each side and its record should be forwarded to the
Nigam.
Superintending Engineer/P&D,
DHBVN,Hisar.
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