Download 1.7 Design, manufacture, assembly and installation requirement

Volume-III of IV
Table of Contains
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
2.0
2.1
2.2
2.3
2.4
3.0
3.1
3.2
3.3
3.4
3.5
4.0
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
4.16
4.17
4.18
4.19
General ............................................................................................................................ 214
Scope of Work ................................................................................................................ 214
Standard .......................................................................................................................... 214
Climatic Condition .......................................................................................................... 215
Operating Condition ....................................................................................................... 215
System Data .................................................................................................................... 216
Insulation Co-ordination ................................................................................................. 216
Design, manufacture, assembly and installation requirement ........................................ 216
Name plates, Identification and Miscellaneous items .................................................... 217
Corrosion and Deterioration Protection .......................................................................... 218
Panting and Finishing ..................................................................................................... 218
Earthing ........................................................................................................................... 218
Test and Approval ........................................................................................................... 218
THREE PHASE POWER TRANSFORMER ................................................................ 221
Technical Requirement ................................................................................................... 221
Windings ......................................................................................................................... 222
LOW TENSION SWITCHGEAR .................................................................................. 224
AUTOMATIC POWER FACTOR IMPROVEMENT (PFI) PANELS ......................... 228
BUS-BAR TRUNKING (BBT) ...................................................................................... 231
Technical Requirement ................................................................................................... 231
Specification of BBT System ......................................................................................... 232
Construction and Assembly of BBT ............................................................................... 232
Test
…………………………………………….233
Installation ...................................................................................................................... 233
DIESEL GENERATOR ................................................................................................. 233
Engine ............................................................................................................................. 233
Cooling............................................................................................................................ 234
Filter ................................................................................................................................ 234
Engine Protection ............................................................................................................ 234
Fuel Injection Equipment................................................................................................ 234
Exhaust............................................................................................................................ 234
Lubrication ...................................................................................................................... 235
Silencer ........................................................................................................................... 235
Radiator ........................................................................................................................... 235
Governor ......................................................................................................................... 235
Coupling.......................................................................................................................... 235
Mounting ......................................................................................................................... 235
Fuel storage ..................................................................................................................... 235
Starting ............................................................................................................................ 235
Battery Charger ............................................................................................................... 236
Generator ........................................................................................................................ 236
Voltage Regulator ........................................................................................................... 236
Wave form ...................................................................................................................... 236
Insulation ........................................................................................................................ 236
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4.20
4.21
4.22
4.23
4.24
Control Panel .................................................................................................................. 237
Finish .............................................................................................................................. 237
Country of origin ............................................................................................................ 237
The tenderer must furnish the following......................................................................... 237
Automatic Change over Switch ...................................................................................... 238
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Volume-III of IV
E. SUB-STATION EQUIPMENT, BUS-BAR TRUNKING AND
GENERATOR
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Volume-III of IV
E. Sub-Station Equipment, Bus-Bar Trunking and Generator
1.0
General
The specification for the part of the contract mentioned below cover design,
manufacture, assemble, testing and commissioning of Sub-station equipment, Bus-bar
trunking up to 22nd floor roof level and supply, installation, testing and
commissioning of diesel generator at Padma Oil Company Ltd. Head Office Building,
Agrabad, Chittagong.
1.1
Scope of Work
The scope of work and obligation of the specification consists the following as
minimum:
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1.2
Design, manufacture, assemble, test and delivery at site, installation, testing and
commissioning of sub-station equipment, bus-bar trunking and generator in
accordance with all requirement of specification, design and standard.
Supply and delivery of all consumables, equipment and spares needed for
installation, testing and commissioning.
Assemble, pre-wire .and test at factory of all necessary equipment and accessories
i.e. controls, protection relays, space heater, interfacing tem1inals etc.
Supply and delivery of spare parts according to the requirement for one year or
for agreeable period.
Carry out of all routine workshop tests and its complete documentation for all
equipment and machine and to provide all necessary documentation for site
testing and commissioning.
Complete documentation of Sub-Station equipment, bus-bar trunking and
generator and its additional equipment and spares including revision up to the end
of commissioning.
Type test certificate for manufacture/fabrication/assembly of all major equipment
must be attached with the bid.
Standard
The sub-station equipment, bus-bar trunking and diesel generator must be of the latest
International Standard. Particular attention is to be paid to the Electricity Act 1910
and Electricity Rules 1937 (as amended in 1946).
The following main standard shall be followed for design, manufacture, assemble,
installation, test and commissioning of this project:
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International Electro technical Commission
Institute of Electrical and Electronics Engineers
Institute of Electrical Engineers
British Standard
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-IEC
-IEEE
-IEE
-BS
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1.3
Japan International standard
American National Standard Institute
National Electrical Manufacturers Association
German International Standard
International Standard Organization
Bangladesh National Building Code
-J.I.S
-ANSI
-NEMA
-VDE
-ISO
-BNBC
Climatic Condition
The following site conditions shall be considered. If there are specific design
conditions given in the specification, design and data sheet, they shall take
preference.
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1.4
Ambient temperature: Maximum temperature occurs during the period from April
to May reaching 45°C (110°F), Annual mean temperature: approximately 29°C
(84°F)
Relative humidity: April to May 60% to 70% during rainy season, from June to
September, the average Relative Humidity is 80% and reaches extreme values up
to saturation point during longer periods.
Rainfall: Maximum intensity from June to September is 200mm to 250mm.
The climate is tropical and has Marked Monsoon character with seasonal changes
from humid and warm in rainy season to cool and dry in winters.
Operating Condition
The High tension (HT) switch gear, Transformer, Low tension (LT) switch gear,
power factor correction capacitor, Bus-bar trunking and Diesel Generator shall be
suitable for continuous operation at above mentioned climatic condition.
The equipment, except bus-risers, will be located at Ground Floor level of the office
complex and the bus bar trunking will run from sub-station L.T. panel through the
bus-duct along lift core at the middle of main tower building upto 22nd floor roof
level. The main power supply shall be controlled from Sub-station or Electrical room
and each floor area or consumer will have their local control switches at their
respective floor.
The local unit control equipment is described at later part of this specification. All
protective system shall be functional at all times.
The equipment and distribution boards described in the specification shall have
guaranteed standard and of safe and secured supply condition at all possible operation
condition.
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1.5
System Data
The following values for power supply distribution system are standard In
Bangladesh.
Normal System voltage (HT)
Maximum system Voltage (HT)
Normal system voltage (LT)
Operating voltage (LT)
Maximum permissible (LT)
Frequency
1.6
: 11KV
: 12 KV
: 15/231 V
: 400/231 V
: 457/263 V
: 50 Hz
Insulation Co-ordination
The insulation level for vacuum Circuit Breaker, dropout fuse, load break switch,
lightning arrester and transfom1er are specified below. Max. Service voltage and
rated voltage shall be according to IEC standard.
According to IEC standard service voltage
Maximum service voltage shall be considered
The respective test voltage shall be
Impulse withstands test voltage (BIL)
Power frequency withstands test voltage
Lightning arrestor standard voltage
1.7
: 11 KV
: 12 KV
: 75 KV
: 28 KV
: 12 KV
Design, manufacture, assembly and installation requirement
All materials, equipment, accessories shall be designed, manufactured, installed,
tested and commissioned according to standard indicated in item 1.2 of this
specification, and modem Engineering practice. All parts of equipment & installation
must be suitable in every respect for continuous operation at maximum out put under
various pem1issible load and climatic condition.
The Switchgear shall meet the following recommendations:
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1.7.1
H.T. switchgear IEC 298/694
L.T. switchgear assemblies IEC 439-1
Circuit Breakers IEC 56
Voltage Transformer IEC 186
Current Transformer IEC 185
Relays IEC 255
LV wires IEC 695
Country of Origin
The country of origin of all components to be supplied under this contract shall be:
UK/ USA/ GERMANY/ FRANCE/JAPAN
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1.7.2
Pre-Shipment Inspection
The Contractor shall be obliged to arrange pre-shipment inspection of all major
equipment, such as Transformer, Bus-bar trunking, HT & LT Switchgear component
and Generator at the factory where those equipment are manufactured and assembled.
The inspection shall be done by the Employer or Consultant or by any authorized
representative of the Employer, to the factory or factories, which country of origin,
the Contractor mentioned in their bid as country of origin of such equipment.
1.8
Name plates, Identification and Miscellaneous items
The Contractor shall supply and install the following in the Padma Oil Company Ltd.
Head Office Building Sub-station:
1.8.1
Name Plates
The final identification of all parts of the system shall be done after commissioning.
Engraved nameplates shall be provided on each part of the system, For example, for
each switchgear line up and for each compartment in each line up. The nameplates
shall be of approved design and type. During commissioning, all equipment shall be
provided with temporary identification sticker. The Contractor shall indicate same
identification of all parts in their as-built drawings.
1.8.2
Identification
All functional devices such as circuit breakers, bus-bars, feeders etc shall be provided
with standard and approved type of identification. The Contractor shall indicate same
identification of devices, feeders etc. in their as-built drawings.
1.8.3
Danger Sing
Regulation type "DANGER" sign, "NO ADMITTANCE" notices etc. shall be
installed in all switch room entry door as per requirement of BPDB/ DESA/ DESCO.
1.8.4
Rubber Mat
The Contractor shall provide in front of all the High Voltage switchgear a rubber mat
of 6mm thickness and. 1000mm width in continuous roll for the full length of the
switchgear room.
1.8.5
Single Line Diagram
A copy of single line diagram shall be suitably framed and mounted in the switchgear
room.
1.8.6
Audible Alarms
Audible alarms shall be provided in the Switchgear room. They shall be manually
switching off type.
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1.9
Corrosion and Deterioration Protection
The Contractor shall provide protection against corrosion and deterioration protection
of all materials supplied and installed.
1.10
Panting and Finishing
Protective painting shall be done for all equipment in accordance with general
practice and recognized methods as per the paint manufactures and in according to
the current edition of DIN 55928 "Corrosion protection of steel structure" to meet the
tropical condition at site.
The cubicle shall be epoxy polyester power finish, finely structured and color shall be
RAL 7032 (pebble-grey)
1.11
Earthing
Each electrical equipment must be provided with minimum one earth terminal of
sufficient size as per IEE, IEC standard and specification of equipment manufacturer.
The sub-station equipment, bus-bar trunking, and all other electrical installation shall
be provided with earthing, earth pit as per design, standard schedule and direction of
Engineer.
1.12
Test and Approval
All equipment, material and workmanship which require any form of approval by the
Bangladesh Government or a Local Authority, like BPDB, DESA, DESCO,
Bangladesh Licensing Board, Bangladesh T & T Board, Bangladesh Fire Department,
and so on, must be appropriately approved and satisfactorily passed all necessary
inspection and test procedure imposed by them. The test personnel must be qualified
and approved by the concerned department of Bangladesh Government. The Test
procedure, Test equipment, etc., must satisfy the requirement of international
standards [item 1.2 of this specification] as well as, the respective department of
Bangladesh Government.
The switchgear shall be provided with earth switch to be interlocked with VCB.
Provision shall be made for earthing of cables by means of earthing switch of quick
make type, able to earth the cables when CB is in the disconnected position.
The earthing switch shall be located in the cable compartment and shall be operated
from the front to any cubicle and independent on the action of the operator. The
earthing device shall be able to close against the rated S.C. current. Padlock facilities
shall be fitted to enable the earthing switch to be locked in both positions. The
position of the integral earthing shall be visible from the front of the switch board.
Mechanical interlocks shall be provided to avoid any mal operation such as:
a) Closing of the earthing switch when breaker is in service position
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b) Inserting the breaker when the earthing switch is in closed position. Integral
earthing of the breaker transfer type shall not be accepted.
A capacitor divider shall be fitted near the earthing switch. It shall be connected to a
neon bulb indicator of the potential tester located in the front side of the panel.
1.12.1
Disconnecting Switches
The disconnecting switches shall have rated voltage of 12KV and rated current 630A
with rated S.C current 16KA.
The disconnector switch shall only operate under no load conditions, suitable
interlocks with C.B. shall be provided and indication as well of no load (OFF) and
load (ON) conditions. There shall be interlocks so as to prevent the cable being
earthed when the disconnecting switch is in ON position. Similarly there shall be
interlock to prevent any operation when the disconnecting switch is in Earthing
position to ON position. The switch shall not operate direct from ON to Earth
position.
Disconnecting switch shall be simple, robust, maintenance free, life expectancy over
20 years and as per JEC 196 and ANSI 37.32 or equivalent standard.
1.12.2
Vacuum Switch
Rated voltage 12 KV
Operating voltage 11 KV
No. of Pole =3
Interrupting chamber = Vacuum at 10-5 to 10-6 Torr
Life = Over 20 years
S.C. current = 16 KA
Closing coil and Trip coil shall operate at 100 Volt AC/DC
Standard JIS C460S or ANSI-C 37
1.12.3
Current Transformer (C.T)
The transformer must comply with BS 3938, VDE 0414 and IEC 185
The C.T. should be cast resin insulated with class 5P10 for protection and class 0.5
for metering. The rated over current factor and burden should be matching with
operating burden of the connected equipment to prevent the instruments from being
damaged.
1.12.4
Potential Transformer (P.T)
Potential transformer must comply with IEC 186. The P.T. should be cast resin
insulated with class 0.5 for metering and class 1 for protection and burden minimum
50VA.
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They shall be on one phase, connected phase to earth Auxiliary contacts shall be
connected in series in the secondary circuits so as to open these circuits when the
voltage transformer are in the isolated position.
The secondary windings shall be suitably insulated and shall be protected by MCB's.
1.12.5
IDMT Relay
The relay for over current and earth fault protection should be of solid state
(microcomputer operated). Minimum setting for over current, earth fault and short
circuit protection including the A.C/D.C converter should be fitted on a draw-out
Double Europe Format (DEF) module. This draw-out module can be housed in a
standard case, in which the module is plugged, should have one screw and one snap
on each terminal for the plant connections. The heavy-duty current plug connector
should provide automatic shorting of the C.T circuits whenever the module is
withdrawn. A make-before-break earth contact should be there to ensure protective
earthing, before the other plug connections can be made. The relay should be suitable
for D.C. shunt tripping to be operated by 100V D.C. voltage from PT. secondary
through a rectifier.
1.12.6
Under Voltage Relay
These shall be such that the breaker is arranged to trip on a falling Voltage of between
85% and 60% of the rated voltage. The relays shall automatically reset when the
voltage recovers to above 85% of the rated voltage.
The relay shall be operated by 100V or 100V D.C. as the type may be from P.T.
secondary through rectifier.
1.12.7
Wiring and Instrumentation
Wiring cable inside the cubicles shall be minimum 1.5sq. mm and with tinned copper
conductors. Current circuits shall be made with minimum 2.5 sq. mm and with tinned
copper conductors.
The HT switchgear shall have voltmeter, ammeter, frequency meter, and all other
meters and indicating lamps as per design and standard.
All cubicles, frames, transformers, measuring and relay circuits shall have protective
earthing with provision for external earth connection.
The VCB/ SF-6 shall be provided with recorder for its operation
The protection system shall consist of over current and earth fault protection and
under voltage as well.
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The bidder shall enclose details of system they proposes, along with single line
diagram, detailed technical specification, manufacturers catalogue and mode of
operation of protection system, with their offer.
Complete physical dimensions and electrical characteristics of the equipment offered
shall be furnished along with the offer.
1.12.8
KWH Meter
Digital type three phase energy meter for recording 11 kv supply voltage from BPDB/
DESA/ DESCO is to be installed in the 11kv switchgear panel as it is shown in the
11kv switchgear design. The meter shall have maximum Demand Indicator (MDI)
and shall be capable of recording energy consumption at two-part tariff, peak hours
and off peak hours. Necessary accessories for installation and for complete function
of the meter, such as CT, PT, conductors, mounting devices, protection items,
earthing terminals etc complete shall be inclusive of this item. The meter, its
installation and function must comply with the requirement of BPDB, DESA,
DESCO or any other related Authority.
2.0
THREE PHASE POWER TRANSFORMER
The Transformer shall be dry type, cast resin insulated and suitable for parallel
operation.
2.1
Technical Requirement
The dry type transformer shall comply with BS 171, IEC 726, VDE 0532 etc. and the
general specification as a minimum will be as follows:
Installation
Transformer
Rated frequency
Terminals
: Indoor type power
: 50 Hz
: HT and L T to be brought out in separate.
HT suitable for XLPE/ PVC Cable of size
185 sq.mm
LT suitable for BBR Connection
Rated primary voltage
Rated secondary voltage
Tap changing
Vector group
L.V. neutral
Bill Level (H.T side)
Maximum system voltage
E. Sub-Station & Generator
: 11 KV
: 0.415 KV
: ± 2.5%, ±5% (Off Load)
: Dyn 11
: Brought out
: 75 KV
: 12 KV (H.T. side)
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0.5 KV (L.T. side)
Cooling
Degree of Protection
: Air Natural
: IP20
2.1.1
Insulation
The transformer shall be manufactured with class F insulation on the high tension
side (permissible average winding temperature rise l00K) and class F on Low Tension
side (permissible average winding temperature rise l00K). The transformer shall be
supplied with a degree of protection IP20. The basic insulation level for HT side and
LT side shall be 75 KV and 2.5 KV respectively. Clamping parts and chases: RAL
5009, coils RAL 3016 or any other approved color.
2.1.2
Iron Core
The three limbs of the Iron core shall be arranged in the same plan and interconnected
by yokes.
The core shall consist of grain oriented laminations which will be insulated on both
sides. The core limb laminations shall be mitered at the joints to the yoke. .
2.2
Windings
2.2.1
High Tension Winding
The high-tension coils should be wound together with a high-grade insulation sheet
from aluminium strip and potted under vacuum up to the terminals.
The external insulation shall comprise of mixture of epoxy resin and quartz powder to
make the winding maintenance free, damp proof and suitable for service in the
tropical atmosphere.
Re-connectable tapping links in the high-tension winding shall permit adjustment to
the system condition. They shall be mounted on the low-voltage side of the
transformer.
2.2.2
Low Tension Winding
Aluminium shall be used for low-tension strip winding. The width of the aluminium
strip shall be equal to the coil length to considerably reduce the axial short circuit
forces. The conductor and insulating material shall be bonded together by heat
treatment and form a compact unit which will be scaled against moisture.
2.2.3
Winding Clamping
A clamping frame shall hold the iron core and coils together. The coils shall be
supported by resilient spacer blocks, which shall provide effective coil-to-coil and
core-to-core damping. Lifting eyes and earthing bolts will be fitted to the top and
bottom clamping frame members respectively.
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2.2.4
Temperature Monitoring
The temperature monitoring system shall protect the transformer winding against
overheating due to increased ambient temperature or overload and shall permit
utilization of the full transformer power at any required load cycle without hazard to
the transformer.
The transformer shall be fitted with two temperature monitoring system as standard
equipment. One shall be connected to give an alarm & the other for tripping. The
response temperature difference between the two systems shall be 20º K.
The tripping unit required for the monitoring system shall be located in the medium
or low-voltage distribution cubicles.
2.2.5
Time- delay relay
As the control supply for the temperature monitoring system will be taken from the
secondary side of the protected transformer, it will be necessary to incorporate a time
delay relay. This relay shall bridge the time that elapses from the instant of
transformer switch on unit to the relay in the tripping unit picks up and will interrupt
the tripping circuit.
2.2.6
Temperature Sensor
The response temperature of the sensor shall be, selected by the manufacturer
according to the class of insulation involved and the mounting position in the
winding. The sensors shall be connected to terminals mounted on the top of the
clamping frame.
The temperature sensors shall be temperature sensitive resistors connected in series
and shall be embedded in the three low-tension windings. A specific increase in their
resistance shall cause the contacts to operate (1 NO + 1 NC).
2.2.7
Noise
Special design measure shall reduce the noise level of cast-resin dry type transformer.
2.2.8
Terminal Connection
High Voltage
As special safety, precaution shall be required against accidental contact with live
parts, the terminal link strip shall be equipped with contacts to receive cable lugs. All
unquoted and live metal parts on the high-tension side of the transformer shall be
protected with flame inhibiting polycarbonate.
Low Voltage
The low-tension phase and neutral terminals shall be arranged at the top for Bus-Bar
Trunking (BBT) or cable connection as per design.
2.2.9
Transformer Earthing
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The brought out transformer neutral shall be, solidly earthed by same size earth
conductor, to the separate earth pit.
2.2.10
Structure Borne Noise Suppression
The transformer shall have structure borne noise reduction unit and it will be a
metal/rubber element, which shall be shaped to securely anchor the transfom1er at the
point of installation.
2.2.11
Truck
The transformer shall be equipped with a truck with plain wheels for travel
lengthways or sideways. The truck shall be bolted to the lower clamping frame
members and shall have four towing eyes.
2.3
LOW TENSION SWITCHGEAR
The Low Tension Switchgear shall be prefabricated, pre-wired, freestanding, type
tested, locally assembled by approved assembler conforming to IEC 439-1 and ISO
9001 for 415V, 3-Phase, 4-wire, 50Hz operation.
2.3.1
Switchgear Design
The switchgear shall be pre-fabricated, complete and ready for erection on the site.
The switchgear shall be totally enclosed, and suitable for indoor installation. All parts
shall be adequately and efficiently protected against accidental touching.
The switchgear cubicles shall confom1 to relevant provisions of BSIIECNDE and
shall be adequate in all respect to accommodate the cables, circuit breakers, meters,
cable termination's and interconnection as indicated in the schedule, specifications,
design, and be provided with lockable doors. All apparatus & components shall be
easily accessible from the front as required for inspection, replacement and repair.
The switchgear shall be of tropical design, suitable for climatic condition (item-1.3)
The switchgear shall conform to the following data:
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Operating voltage Frequency
Frequency
Number of bus-bars
Bus-bar materials
Degree of protection of Bus-bar chamber
Maximum protective current
(Cos. phai = 0.2, t = 0.1 see) of bus-bar
Rated short time withstands Current of bus-bar
Maximum protective peak Current of bus bar
Rated Impulse withstand voltage
Rated Insulation voltage
E. Sub-Station & Generator
: 415 V
: 50 Hz
: 5(LI, L2, L3 N & PE)
: Copper (HDBC)
: IP41
: 80 KA
: 40 KA
: 17 KA
: 8 KV
: 1000 V
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The Switchgear shall be designed to withstand internal arcing faults confom1ing to
PEHLA guideline No.2 i.e. 50KA (m1s), Coso=0.2, t=0.2 sec. for a symmetrical short
circuit current of 50KA during 1 second as a minimum. All parts of the switchgear
including apparatus shall be designed to withstand without being damaged, the
mechanical and thermal strain of the prospective short circuit current or, where
protected by circuit breaker, the interrupting current of the circuit breaker.
As Type and Routine Tests laid down in IEC form the basis for verifying the
characteristics of tested switchgear assemblies, the bidder shall submit the necessary
type test results of the proposed LT switch gear. Routine tests shall be, done in
manufacturer's factory in presence of the Employers representative before shipment
of the equipment.
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2.3.2
All cables, feeders, buses shall be provided with approved type of identification
Outgoing cables shall be arranged in separate spacious cable chambers.
Protective screens shall be arranged between main bus-bar and cable space.
Terminals for power cables shall be protected against accidental touch.
Interior control writing shall be accommodated in flexible plastic conduits.
Wiring inside the cubicles shall be made with minimum l.5mm2 and with tinned
conductors.
The switchgear shall be suitable for bus-bar trunking entry, if required as per
design and schedule.
The switchgear shall be suitable for additional space of approximately 20% for
future extension.
The switchgear shall be arranged strictly in accordance with the layout drawing
and direction of Engineer.
The switchgear shall be of modular type design. The apparatus of each functional
group shall be assembled on a common base.
Cubicle Construction
The distribution sections shall be of carcass construction and the carcass shall be
augmented with various cladding plates as required. The cubicle shall be dust and
vermin proof.
The sheet steel metal thickness shall be minimum (16SWG) 1.5mm for door, top
plate, bottom plate, side, back plate and 14SWG (2.0mm) for frame, module
mounting plate respectively. The top plate, bottom plate and side plates shall be
possible to pull for easy removal. Rear access door shall be provided.
The paint of the plate shall be semi-textured powder spray finish with polyester
compound, color RAL 7032-pebble gray or other approved color. The paint thickness
shall be minimum 0.5mm and chemical resistant to paraffin benzola petrol. Dilute
acids (10%), dilute alkalis (10%)
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Creepage and clearance paths shall conform to VDE0l10 insulation group C or
UL508 table 18.1 and BS 162 table 4.
The electrical equipment inside the panel shall be finger proof.
Cubicles shall be of frame structure fully metal enclosed internal sub-division in to
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Bus-bar compartment
Equipment compartment
Cable compartment
Each vertical compartment shall be furnished with space heater to prevent
condensation of moisture.
2.3.3
Cable Entry and Termination
All cables to be connected to the panels shall come from bottom. The cable
compartment shall have enough space for all incoming and outgoing cables and also
for its assembly and maintenance of panels.
The bottom plate shall be split and removable type to facilitate cable entry. Plates for
cable glands for incoming and outgoing cables are to be provided with accessories.
2.3.4
Bus-Bar (Main and Secondary)
The bus-bar shall be installed with rigid non-tracking, non-flammable and
110nnhygroscopic insulating supports capable to withstand magnetic forces imposed
by short circuit current at least equal to the interrupting of the switchgear bus main
breaker. The switchgear bus-shall be of HDBC copper designed to carry continuously
the rated current, operating at its maximum future rating, without exceeding
temperature rise requirement specified in referenced standards. All joints in bus-bar
shall have non-oxidizing contact surfaces minimum contact resistance and shall be
insulated with removable insulating fittings, which will provide insulation at least
equal to that of the bus-bar insulation. The bus-bar shall be manufactured and tested
to comply with B.S 159 or equivalent continental standard to withstand a fault level
of 65KA r.m.s. for one second.
2.3.5
Ground Bus
An uninstalled copper ground bus shall be furnished throughout the entire length of
the switchgear and connected to the transformer neutral. All switchgear equipment
requiring grounding shall be connected to this bus. Copper cross-section of ground
bus shall not be less than half of phase bus. The ground bus shall be connected with
the earth pits as per design and direction of Engineer.
2.3.6
Circuit Breakers
The circuit breakers shall comply with IEC157, BS4752 with horizontal isolation.
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The ACB/MCCB shall be quick make, quick break, trip free, indicating type and shall
have inverse time limit characteristics with adjustable overload, short circuit and
instantaneous magnetic trip element functioning on overload above the normal
operating range. All circuit breakers shall be trip-free. ACB's shall be motorized
operated type.
Each breaker shall be capable of carrying rated full load current continuously without
exceeding the temperature rise specified in the referenced IEC standard. Circuit
breaker insulation shall be co-ordinated with that of the switchgear structure and shall
be designed for use on a 600-Volt system. All circuit breaker lugs shall be of solder
less mechanical type.
Breaker main contact surfaces and all secondary device contact surfaces shall be
silver-to-silver, designed and fabricated to be self-aligning and to resist burning and
deterioration.
All breakers of L.V Switchgear system shall be of same manufacturer.
Padlocking facilities shall be provided for main incoming circuit breakers, bus
coupler and all main circuit breakers in local panels.
All main breakers shall be equipped with solid state phase over-current tripping
devices to provide interchangeable and independently adjustable over-current and.
short circuit protection. Trip settings will be co-ordinated to provide selective trip
over-current protection. The Contractor shall furnish tripping devices with
characteristics and trip ranges, which will permit this co-ordination.
The MCCB’s shall have the following minimum symmetrical interrupting capacity as
per B.S and IEC at 415V A.C., if not indicated otherwise:
Upto 50 ATP
51 ATP to 100 ATP
101 ATP to 300 ATP
301 ATP to 800 ATP
801 ATP to1600
ATP 1601 ATP to above
2.3.7
: 15 KA
: 25 KA
: 35 KA
: 50 KA
: 65 KA
: 80 KA
Current Transformer
All current transformers shall comply with IEC185, BS3938 and shall be of suitable
class, rating and accuracy depending on the duty.
2.3.8
The LT switchgear shall be complete with all meters, indicators, switches, relays, and
so on as per design, standard and direction of Engineer.
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2.4
AUTOMATIC POWER FACTOR IMPROVEMENT (PFI) PANELS
The Power Factor Improvement panel (PFI) shall be sheet steel clad dust and vermin
proof, freestanding, floors mounting indoor type, type tested, locally assembled by
approved assembler confirming to IEC-439-1.
2.4.1
Construction
The metalized dielectric capacitors should be construction as follows:
The metalized coatings to be vapor-deposited on a plastic folium. The folium should
act both as a support and dielectric. The capacitors should be of single wound section
design; i.e. the sections for each of the three phases should be wound round the core
successively and isolated by a separation folium. The wound section is to be fitted in
an aluminum jacket.
The capacitor shall not contain any liquid impregnate. They shall be with SF6 or N2
gas to stop entrapped air from oxidizing the vapor deposited inside in order to
improve life expectancy, capacitance stability, overload capacity and switching
durability.
2.4.2
Operating Characteristics
Capacitors shall have the following operating characteristics:

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2.4.3
High reliability
High overload capacity (l.5x rated current for harmonic loading)
High capacitance stability
High switching durability
High temperature class (ambient temp. upto +55 degree C)
Long life expectancy
Touch-proof terminals
Low losses
Maximum up to 0.5 W/KVAR at terminals
Maximum up to 0.2 W/KVAR in the dielectric
Self-healing: Switching peaks may overload capacitors and lead to flash-over in
the dielectric. The resultant arc evaporates the metalized layer near the puncture.
Faulty points in the dielectric should thus be isolated and the capacitor can
continue operating without any trouble.
Easy to install, operation, inspection etc.
Low weight
Maximum Safety for Personnel and Plant
The capacitor housing shall have expansion seam that opens and lengthens the
housing. This should break the lead between the wound section and the terminal at
the rupture joint and the capacitor should thereby be isolated from the system.
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2.4.4
Regulation
The capacitors shall be in compliance with requirement with following regulations:
DIN EN 60831-1
IEC 70
IEC 831-1
2.4.5
Technical Data
The PFI plant shall comply with the following technical data as a minimum:
Rated voltage
Max. Permissible operating voltage
Max. Permissible current
Rated frequency
Capacitance tolerances
Degree of protection
Foil/Foil test voltage
Foil/enclosure test voltage
Life Time
Cooling
Housing/Color
: 415 V
: 460 V
: 1.5 x rated current
: 50 Hz
: -5 to +10%
: IP 54
: AC Test with 2.15 x rated Voltage
: 3 KV
: Min 80000 hours
: Self-cooled
: Ral 7032 (Light Gray) Electrotating
applaud powder coating
Details of Capacitors such as manufacturers catalogue, operation and maintenance
manual, type test certificate etc. must be submitted with the offer otherwise the bids
shall be rejected.
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2.4.6
Power Factor Correction Relay
2.4.6.1
Construction
The digital type controller should be fitted in housing for door mounting. Degree of
protection should be IP54 (front) and IP20 (rear), safe to touch. The front should have
two operating buttons and a measured value display. The terminals and their diagram
should be on the rear side.
2.4.6.2
Connection
The controller should be suitable for system voltages from 200V to 690V at 50 to
60Hz & for 1 A & 5A current transformers. The control voltage is in all cases 230V (15 to 20%).
2.4.6.3
Automatic setting of the set point range
The Controller shall have self-adaptation facility. Self-adaptation means that it is no
longer necessary to set the c/k value (c: power rating of the first capacitor bank k:
transformation ratio of the current transformer) during commissioning of the Control
Unit, after plant extension or when a current transformer is modified .A maximum of
6 capacitor branches can be controlled in any order via 6 output relays (indication by
LED's). Two further output terminals can be used for fault indication (P.F. too low or
too high).
2.4.6.4
Technical Data of PFC Relay
The PFC shall comply with following technical data as a minimum:
Standard
Rated Voltage
Supply Voltage
Rated frequency
Consumption
No of steps
Step function ratio
Response time (increase)
Response time (decrease)
Extension of response time
C/K value
Housing of Relay
Connection
Ambient temp
Altitude
2.4.6.5
: DIN, VDE 0106, 0160 IEC 0348
: 200V to 690V
: 230 V (±10%)
: 50Hz
: 2VA
: Max. 31 at step function ratio: 1,2,4,8,16
: Variable
: 30 second
: 3 second
: Under fast changing load situation the
response to be delayed to 2/3 min.
: Automatically adjusted in the controller
Range 0.01 to 0.1
: Droplets, IP20
: Wire Terminals (SIGUT)
: 40 degree. C.
: up to 1000 m above see level
Display
In automatic operation of the PFI panel, the following measured variables must be
shown on the display:
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2.4.6.6
Cos phi (P.F)
Apparent current (A)
Measuring circuit voltage (V)
Active power (KW)
Apparent power (KVA)
Reactive power, actual (KVAR)
Harmonic voltage
The Magnetic Contractor of PFI unit shall incorporate following technical data
 Air contractors shall comply to DIN, VDE 0660 and IEC 158-1
 Insulation rating
: 750 volt (minimum)
 Ambient temperature
: -25 to 55°C
 Coil voltage tolerances
: 0.85 to 1.1 times rated control
voltage
 Switching frequency in make/break
operations per hour- when switching-on
to discharged capacitors 90
: 90
 Contact endurance (make/break operations) : 100000
Discharge Coil
The coils should be suitable for discharging of 25 KV AR and 50 KYAR capacitor
banks in less than 5 and 10 second respectively.
2.4.6.7
LV HRC Fuse
HRC Fuses with non-insulated gripping lugs shall comply with DIN, VDE 0636 and
IEC 269 and shall have breaking capacity 120 KA.
Dimension of HRC fuse should be in conformity to DIN 43620
3.0
BUS-BAR TRUNKING (BBT)
Fully enclosed by insulated housing, the compact bus-bar trunking system shall be
installed from ground floor electrical room low voltage (BNA) and essential (BSA)
panels upto 22nd floor roof level of the building to facilitate power distribution system
to the DBS of all floor, lifts etc. There shall be two bus-bar trunking, one for normal
power (BBT-N) and the other for essential power (BBT-S) supply, common for all
floors.
3.1
Technical Requirement
The low impedance prefabricated rising main bus-bar trunking shall be suitable for
use in installation conforming to IEC-439.1.
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The bus-bar trunking system shall be comprising bus-bar riser, elbow, tee, expansion
unit, tap off box connection, circuit breaker, bend, flange, maintenance plug, closed
type transformer connection unit, and all other accessories complete for proper
installation on wall, with roof and in bus-bar riser duct. The BBT system must have
minimum 120 minutes fire barriers.
3.2
Specification of BBT System
1
2
3
4
5
6
7
8
Standard
Climatic test
2.3
2.30
Maximum ambient Temperature
Degree of protection
Color
Rated insulation voltage
Frequency
Rated current of bus-bar
9 Phase configuration
10 Rated short circuit current capacity
(KA), 6 cycle BBT-N/BBT-S
11 Bus-bar materials
12 Fire withstand Capacity
13 Special features
14 Drawing and catalogue
15 Type test certificate
3.3
: IEC 439-1 & VDE0660 Pt500
: Damp heat, constant, to IEC 68 Pt
: Damp heat cycle to IEC 68 Pt
: 45º C
: IP54
: Approved color
: Minimum 1000 Volt A/C
: 50 Hz
: 2500A (BBT -N), 1250A(BBT -N),
630A (BBT-S), 1250A (BBT-S)
: TP-N-E, (100% neutral)
: 150 KA/85 KA
: (HDHC) Copper
: 120 minutes fire rating
: Single bolt clamping
: Drawings supported by catalogue to be
submitted for the proposed riser system
with detailed information, dimension etc.
: Valid type test certificate for manufacture
& assembly is to be attached.
Construction and Assembly of BBT
Tap-off units must be designed in such a way that the units can be fitted or removed
while the system i.e. the main bus-bar trunking is energized. The BBT shall have 120
minutes fire barrier. .
Circuit breakers in the Tap-off units shall be of quick-make, quick break, trip-free,
indicating type having adjustable thermal over-current and adjustable/instantaneous
Electro-magnetic short circuit release having the rated interrupting capacity.
All the components of the BBT i.e. main bus-bar reduction unit, fire barrier, fixing
bracket, tap-off boxes, circuit breakers, elbow, tee, feed nut, end cover, expansion
unit, reduction unit, etc. shall be from the same manufacturer.
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3.4
Test
Manufacturers test certificate for manufacturing and assembly are to be attached
along with valid type test certificate.
3.5
Installation
The BBT system shall be installed on floor, ceiling, walls, bus-duct etc, with all
necessary cutting, breaking, cleaning, making good in all respect with nuts, bolts,
lugs, isolation joint stacks, hangers etc. complete accessories. The bus-bar trunking
shall be installed, tested & commissioned as per design standard, specification and
instruction of the Engineer/Employer. The Contractor shall be responsible for
supplying all materials, equipment, tools, etc required for installation, testing and
commissioning of the bus-bar trunking system, starting from sub-station LT panel
upto 22nd floor roof level of the building.
The Contractor shall put their attention by keeping co-ordination with other
Contractors of this project for installation of BBT system as per design and direction
of Engineer, so that no conflict arises for BBT system installation. The Contractor at
their own cost shall break and make good of any part of the building, if required for
installation of BBT. But before proceeding with any of such breaking, the Contractor
must take written permission from Authorized Engineer.
4.0
DIESEL GENERATOR
The diesel generator with super sound proof Acoustic Canopy (75 to 80 dB @ 1
meter) is required for essential power supply in the Padma Oil Company Ltd. building
at Agrabad, Chittagong. The generator shall be located at the ground floor of the
building. Essential light, lift, fire pump, water pump, telephone PABX etc. shall be
connected to this generator.
The diesel generator shall have rating min. 1100 KVA, 415V, 3-phase, 4-wire, 50Hz
and will be driven by diesel engine.
4.1
Engine
The engine shall be 4 stroke six cylinder (min), vertical line direct injection, water
cooled, turbo charged, diesel fired, with inter coolers, of generating capacity not less
than 1100 KW under standard condition of 29.92 inches of mercury barometer
pressure and 35°C air temperature. The engine overload capacity shall be 10% (min)
for one hour operation at conditions specified under B.S. 649, 1958. The engine is to
be incorporated with the protection system to shut down automatically in the event of
low oil pressure, high water temperature, or reverse power.
The engine shall also have replaceable cylinder liners of the wet sleeve type and
replaceable valve seat inserts. Exhaust manifold should be water-cooled.
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4.2
Cooling
The engine shall be provided with tropical duty radiator in conjunction with belt
driven system, separate core for the inter coolers radiator fan and air duct adapter.
Coolant water shall be circulated by centrifugal water pump controlled by thermostat
with full flow by pass.
4.3
Filter
4.1.1
Air Filter
Dry paper replaceable element type, and designed for easy maintenance are to be
provided. The turbocharger shall be of such design as to be of self-cleaning.
Turbocharger requiring periodic cleaning will not be acceptable.
4.1.2
Oil Filter
Multi-bowl, replaceable element, full flow type.
4.1.3
Fuel Filter
Multi-bowl, replaceable element, full flow type.
4.4
Engine Protection
The engine shall be equipped with pre-warming alarm devices, which will actuate
visible and audible alarms in the event of low oil pressure or excessive jacket water
temperature and over speed. The engine shall be equipped with automatic safety
shutdown controls which shut-down controls and thereby shut-down the engine in the
event of low lubricating oil pressure or high jacket water temperature, Over speed,
and reverse power, units shall have auxiliary contacts for a future remote alarm.
4.5
Fuel Injection Equipment
This system should be comprised of multiple plunger injection pumps, fuel lines,
primary and secondary fuel oil filter, fuel transfer pumps and injectors.
4.6
Exhaust
Exhaust manifolds are to be ducted to the turbocharger mounted by the side of the
engine through silencer and flexible exhaust pipes. All exhaust components are to be
finished with heat resistant aluminum paint.
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4.7
Lubrication
A gear type lubricating oil pump shall supply oil under pressure to main bearings,
pistons, turning gears, and camshaft bearings and valve rocker mechanisms. Pistons
shall be sprays cooled. Full flow lubricating oil filters shall be provided and so
located that lubricating oil is continuously filtered, except during periods when oil is
bypassed to protect vital parts such as when filters are clogged. Replaceable resin
impregnated cellulose type filter elements shall be accessible and easily removable.
Filter system shall be equipped with spring loaded bypass valve as an insurance
against stoppage of lubricating oil circulation in the event filters become clogged. A
suitable water-cooled engine-mounted lubricating oil cooler shall be furnished.
4.8
Silencer
The engine shall be equipped with low noise type silencer, preferable hospital type.
4.9
Radiator
Radiator shall be filled up with distilled water and anti-corrosive coolant.
4.10
Governor
The electronic governor shall be supplied as per manufacturer’s standard.
4.11
Coupling
A substantial cast iron flange and the alternator driven by means of suitable flexible
coupling, to dampen the shock should couple engine and Alternator.
4.12
Mounting
The engine shall be mounted on a steel skid type base frame suitably strong for
rigidity and to withstand vibration and shock. The frame shall have arrangement for
fixing the generator on the floor.
4.13
Fuel storage
A full load running 8-hour capacity fuel tank is to be supplied along with the
generator. Convenient arrangement shall be made by the Contractor for automatic
passing of fuel from fuel tank to the engine.
4.14
Starting
Electric starting motor with solenoid and overrunning clutch drive shall be furnished
on the engine. The starting motor shall be of the required voltage recommended by
the engine manufacturer. Batteries shall be provided, and shall be of lead acid type of
sufficient capacity for at least 90 seconds at firing times speed, and also with capacity
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for starting the engine a minimum of four times, mounted on the unit or in separate
rack located beside engine, including hydrometer, rack and other necessary item. The
engine shall start automatically after receiving normal power failure signal from
normal bus LT panel.
4.15
Battery Charger
A completely automatic battery charger shall be provided, which shall maintain the
starting batteries always at full charge. It shall have a high charging rate (12 amps)
compatible with the batteries and, when the batteries are brought up to full charge, it
shall automatically reduce the charge rate to a continuous trickle charge. An ammeter
indicating the high charge rate and fuses on input and output to protect the rectifier
and transformer shall be incorporated.
4.16
Generator
The generator shall have a continuous rating as indicated 1100 KVA at 0.80 P.F
415V, three phase, 4 wire, 50 Hz, brushless, self- exciting, self regulating, single
bearing screen protected, drip proof, fan ventilated with conventional wound stator
and salient pole rotating field system, incorporating both the A.C. exciter armature
and three phases full wave silicon diode with surge absorber main field rectifier on a
common shaft and built in permanent magnet poles. The alternator is to be self
excited from its output through a static automatic voltage regulator. Under speed
protection and short circuit current protection equipment are to be incorporated with
the generator.
4.17
Voltage Regulator
The terminal voltage should be maintained within ± 2% of its value at any balanced
load, at any power factor between unity and 0.80 lagging inclusive of both resistance
variations with temperature and of the usual engine speed regulation with load. A
voltage adjusting rheostat shall be provided for field adjustment of ± 5% of rated
voltage.
4.18
Wave form
The output voltage waveform shall be within B.S. 2613 and B.S 4999 limits.
4.19
Insulation
Insulation shall be of class H. All windings should be impregnated with Class-H
thermo-setting insulating varnish for use in tropical climates.
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4.20
Control Panel
A cubicle type enclosure of substantial gauge (1.5mm min.) pre-stressed sheet steel
construction with lockable front door, two removable side entry gland plates and
fitted on the top of the alternator includes.
1 - Voltmeter 0-500V scaled flush mounting moving iron type
1 - Voltmeter phase selector switch
1 - Ammeter 0-2000A flush mounting moving iron type
1 - Ammeter selector switch
3 Current transformer 1500 A with adequate burden for metering and protection
1 - Frequency meter
1 - 1500A or suitably rated circuit breaker with OFF/ON switch with both magnetic
and thermal protective device for short circuit and overload protection
1 - Set of push button/key for start, stop and shutdown circuit test
1 - Set of indicating lamps and audible alarms for shut- down on:Low lube oil pressure
High water temperature
Over speed
Fail to start
Reverse power supply
1 - Duty selector switch for Auto / Manual start.
1 - Mains voltage off modes sensing relay
1 - Cancel alarm push button
1 - Emergency stop button
1 - Battery charge indicator
1 - Set of automatic mains failure detecting unit and auto start-up system for the
generating set.
4.21
Finish
Standard finish is to be given with two layers of under coat/primer finished with oil
resistant industrial enamel paint.
4.22
Country of origin
Country of origin of the generating set shall be USA/ UK/ GERMANY/ FRANCE/
SWITZERLAND/ JAPAN.
4.23
The tenderer must furnish the following
1. Detailed Technical Catalogue including the fuel consumption per hour, model
nos. of engine and generator, size of fuel tank etc.
2. Certificate from Manufacturer about the country of origin, quality, genuinely and
standard which, support the manufacture of generator.
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3. Detailed list of spares shall be supplied along with the generating set (with no
extra cost) for trouble free operation of the generating set for at least 2000 hrs.,
and one set of tool box with list of tools.
4. Valid type test certificate
4.24
Automatic Change over Switch
The automatic change over switch shall be 1500A, 4-pole, 4ISV, 50Hz and short
circuit breaking capacity of 65KA. The ACS shall be mounted in a panel; free
standing floor mounted type, dust and vermin proof. It shall automatically transfer the
load from main supply to generator in the event of main failure. Display lamps
indicating the healthy condition of generator and main supply shall be provided on
the panel. Suitable earthing block shall be provided with automatic change over
switch. The panel for ACS shall be equipped with indicating lamps, push buttons, etc.
complete.
In the even of main failure, the following sequence of activities would follow:
The generator shall start automatically after a pre-determined time delay adjustment
period of 0-10 seconds (3 attempt cranking with lockout features) and when reached
up to the required speed and voltage, the changeover contractor shall switch from the
mains supply to the generator supply. The generator set shall continue to supply load
until such time when the mains supply returns and following an adjustable period of
0-10 minutes, the load shall be transferred back to the mains supply and the generator
will continue to run on no load for an adjustable cooling period of 0-10 minutes, after
which it shall shut-down and remain in readiness for any future mains failure.
Detailed catalogue of automatic change over switch including its drawings showing
dimensions shall be supplied along with tender.
The country of origin of the auto-change over switch shall be USA/ GERMANY/
FRANCE/ SWITZERLAND/ JAPAN.
The Contractor shall be responsible for supply, installation testing and commissioning
of the generator change over switch and all other consumables items etc. required for
proper functioning as per design, specification and instruction of the Engineer
/Employer.
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