Substation,
Transformer, Generator
A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform
any of several other important functions. Between the generating station and
consumer, electric power may flow through several substations at different
voltage levels.
Substations may be owned and operated by an
electrical utility, or may be owned by a large industrial or commercial
customer. Generally substations are unattended, relying on SCADA for remote supervision and control.
A substation may include transformers to change voltage levels between high
transmission voltages and lower distribution voltages, or at the
interconnection of two different transmission voltages. The word substation comes from the days before the
distribution system became a grid. As central generation stations became
larger, smaller generating plants were converted to distribution stations,
receiving their energy supply from a larger plant instead of using their own
generators. The first substations were connected to only one power station, where the generators were housed, and were
subsidiaries of that power station.
GENERAL SPECIFICATION:
Specification for the parts of this mentioned below cover
design, manufacture, assembly and testing at
the contractor's workshop as well as the supply, delivery, installation,
testing and commissioning of the
sub-station equipment at site.
CLIMATIC
CONDITIONS:
The climate is tropical and has marked Monsoon character
with seasonal changes from humid, warm, rainy
season , summers to cool and dry winters. Maximum temperature occurs during the
period from April to May reaching approximately 43 deg. C (110
deg.F) with a relative air humidity of 60% to 70%.
The annual mean temperature is approximately 29 deg. C (84
dcg.C). During the rainy monsoon month from
June to September, the average relative air humidity is 80% and reaches extreme
values up to saturation point during longer
periods, the annual rainfall, most of which occurs from June to September is 2000mm to 2500mm.
OPERATING
CONDITIONS:
The sub-station equipment will be connected to the 11KV,
3-phase, 50 Hz Bus of Power Development Board/ REB/
DESA/Bangladesh.
STANDARDS:
Al! equipment and materials must be in conformity with
the most recent relevant Bangladeshi laws, standard
rules and regulation. Particular attention is to be paid to the Electrical Act
1910 and Electricity Rules 1937 (as
amended in 1946). All equipment and materials to be supplied, which required
any. Form of approval by the Bangladesh
Government or a Local Authority like PDB/DPDC/DESCO/REB or equivalent must satisfactorily pass all inspection and
tests procedures imposed by them.
Otherwise, all the equipment and materials must be in conformity with
the most recent international rules, regulation, standards and
recommendation: IEC.
STANDARD DATA:
The following standard values for high and low voltage are standard in
Bangladesh.
DISTRIBUTION BUS H1G11 VOLTAGE :
11KV,
MAXIMUM SYSTEM VOLTAGE 12 KV.
LOW VOLTAGE : 415/240V LOCAL VOLT AGE
400/231-OPENING VOLTAGE 457V -MAXIMUM PERMISSIBLE VOLTAGE BY PDB/DESA/REB
FREQUENCY: The standard power
frequency in Bangladesh will be: 50Hz.
DESIGN &
CONSTRUCTION REQUIREMENTS:
All equipment are to be in accordance with the latest recognized rules
of workmanship and modern engineering practice.
All parts of the equipment must be suitable in every respect for continuous
operation at maximum output under the climatic conditions as specified above.
MARKING OF TERMINALS:
The terminals shall be marked in accordance with BS, IEC, VDE or
equivalent standards. PAINTING:
Protective painting shall be done in accordance with general practice and
recognized methods, the paint manufacturer's instruction and
according to the present addition of DIN 55 928, CORROSION PROTECTION OF STEEL STRUCTURE' such as to meet the tropical condition at
site.
EARTHING OF EQUIPMENT:
Each electrical equipment must be provided with an earthing screw of
sufficient diameter or an earthing plate.
INSULATION CO-ORDINATION:
The insulation level for load break switch, lightning arrester and
transformer are stipulated below, taking into account the
maximum service voltage and the rated voltage according to IEC standard, with appropriate impose withstand test voltage and power frequency withstand
test voltage values.
The insulation levels for equipment are as follows:
According to IEC rated service voltage : T1KV
Maximum service voltage shall be considered: 12KV
The respective test voltage shall be :
Impulse withstand test voltage (B1L) : 75KV
Power frequency withstand test voltage : 28
KV
For the lightning arrestor, the IEC standard voltage of 9KV is to be
selected.
4.4 TECHNICAL REQUIREMENTS:
The equipment specified in the following items shall withstand the
impulse levels and test voltages specified by the
recommendations of IEC, as stipulated before. They must be capable of cany ing
the short time current for three seconds and must withstand the
short circuit (Peak value) current.
The rupturing capacity of the circuit breakers is indicated in the
respective items. The switchgear must be designed accordingly
in order to withstand the mechanical short circuit stresses.
They must contain all technical particulars which are mentioned in the
Schedule of Technical Data.
The Owner reserves the right to have routine tests carried out on each
type of equipment at the manufacturers workshop in the presence of his
representative.
4.5 HIGH TENSION SWITCHGEAR:
Fig- HIGH TENSION SWITCHGEAR
SCOPE:
The switchgear shall be pre-fabricated, complete and ready for erection
and suitable for indoor installation.
STANDARDS:
11KV switchgear
must comply with the requirements of 1EC 694,VDE0101,0670 Part-6 74(draft),
0670 Part-7 74(draiY) 1EC republication
298.69 Pahls recommendation No.2 and equivalent British Standard (BS 116-1952)
11K.V Switch Board shall be consisting of cubicles free standing type, for
indoor installation, formed by
pro-fabricated factory assembled. The individual cubicles shall be made of
strong sheet steel (min!6SWG) at all
sides with iron angles and channels welded together.
The board shall be covered and the top shall be provided with pressure
relief, flaps the bottom shall be open the allow
connection of cables via and boxes, necessary holding iron and clamps are
provided.
The front shall be provided with sheet steel doors with special locking
devices and with viewing glasses in order to see the
condition of the switches and the contact.
On the top of the cubicle a sheet steel enclosed relay, meter cabinet
shall be provided.
The iron and sheet steel parts after cleaning by modern methods shall be
painted in the initial layers and a final paint as
such the lacquer shall be a protection against corrosion the tropical humidity.
The final colour of the cubicles will be pebble grey to DIN 43656.
The single busbar system shall be of copper bars to withstand
the required amperage. They are to be mounted on cast resin insulators in each
cubicles.
The single bars shall be marked by the colours as per [EC, VDE or BS
standard.
4.6 CIRCUIT BREAKER:
The circuit
breaker must comply with VDE specifications 0670, Part-102, 1EC Recommendations
and Publication 56, 1EC 695, BS 116, BS 5311
or equivalent ANS & UTE Specifications.
Technical data for circuit breaker
Nominal System voltage :11 KV
Rated normal
current :630A
Number of phases :3
Frequency :50 Hz
Rated short
circuit breaking current(rms) 20KA
Rated short circuit making current duration 3 sec.
Rates short
circuit making current 50KA
D.C component of rated short circuit breaking current36%
Rated lightning impulse withstand voltage 75 KV
Rated Power
frequency withstand voltage (60 sec) 28 KV
No. of operation cycles at the rated normal current 20,000
No. of operation
cycles at the rated short circuit current 100.
4.7 CURRENT TRANSFORMER:
Current transformer must comply with BS 3938, VDE 0414 and 1EC 185.
The C.T. should be cast resin insulated with class 10P10 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, 1th = 80xln,
id=200 In.
4.8 POTENTIAL TRANSFORMER:
Potential transformer must comply 1EC86,. The P.T should be cast resin
insulated with appropriate accuracy class and burden
minimum 50VA. The P.T. secondary shall be protected with MCB.
4.9 IDMT RELAY:
The relay for over current and earth fault protection should be of solid
state (micro-computer operated} type. The complete triple pole, solid state
IDMT relay with adjustable minimum setting for over current earth fault and
short circuit protection including the A.C./D.C. converter.
This module can he housed in a standard case for assembling in cubicles.
The socket which are located in either the rack or the case in which the module
is plugged, should have one screw and one snap-on terminal each for the plant
connections. The heavy duty current plug connector should be provided 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 he suitable
for d.c. shunt tripping to be operated by 110V D.C. voltage from P.T. secondary
through a rectifier or 12/24V d.c. through capacitor rectifier circuit.
Wiring inside the cubicles shall be minimum 1.5mm2 area and with tinned
copper conductors. Current circuits shall be made with minimum 2.5mm2 area and
with tinned copper conductors.
All cubicles, frames, transformers, measuring and relay
circuits shall have protective earthing. Each cubicle shall be
provided with earthling bolt and earthing parts.
The bus bars shall be of copper and fully insulated through their length.
The protection system shall consist of over current protection and earth
fault protection.
The bidder shall enclose details of system be proposes, along with single
line diagram, detailed technical specification and mode of operation of
protection system, with his offer
Complete physical dimensions and electrical characteristics of the
equipment offered shall be furnished along with the offer.
4.10 GENERAL SPECIFICATION OF H T11KV
SWITCHGEAR:
Nominal
System Voltage Highest Voltage for Equipment Type of Switchgear Class of
Switchgear Number of Phases Frequency (Supply) Busbars Rated short circuit
capacity
Svmmetrical
Breaking Current KV
11
Making
Current KV
12
a) Busbars
a) Busbars
b) Vacuum Circuit Breaker
Rated
Insulation Level
Impulse
Withstand Voltage to Earth KV 75
impulse
\VithstanJ Voltage between Phases KV 75
Minimum Dry
Power Frequency Withstand Voltage KV
rms 28
Voltage Transformer
Voltage Transformer
Rated Primary
Voltage KV 11
Rated
Secondary Voltage V 110
Rated
Output/Phase VA 50
4.11 THREE PHASE POWER
TRANSFORMER:
The Transformer shall comply with
IEC726, VDE 0532 etc. and the general specifications will be as follows:
Oil immersed Indoor/Outdoor Type
Power Transformer:
a. Rated
capacity : As
per Schedule KVA
b. Rated
frequency : 50
Hz
c. Rated
primary voltage : 11
KV
d. Rated
secondary voltage : 0.415KV
e. Tap
changing (off load) : ± 2.5%, ± 5%, ± 7.5%
f. Phase
connection : DYN11.
g. I,A,
neutral : Brought
out
h. HI,
level (H.T. side) : 75KV (H.T. side)
i. Maximum
system voltage : 12KV
(H.T. side), 0.5 KV (L.T. side)
j. Cooling : as
per schedule.
furnish following data at 75 deg. C.
a. Iron loss at rated voltage and frequency
b. Copper loss (including supplementary
eddy current loss ) at continuous
rated current (50 c/s) and for winding at 40 deg.C ambient temperature
with the changer in middle position.
c. Impedance voltage with tap changer at
middle position.
d. Voltage
drop referred to rated voltage at rated load with tap changer in middle
position and at unit p.f.
e. Permissible
maximum symmetric three phase short circuit current referred to rated current.
f. Rated no load current (RMS value
referred to rated current).
g. Type of windings with conductor
materials,
h. Class of insulation material.
h. Class of insulation material.
i. Voltage regulation.
j. Temperature after continuous rated
load at 40 deg. C ambient temperature.
In windings
Core
k. one minute double power frequency induced tests voltage applied to:
k. one minute double power frequency induced tests voltage applied to:
H.V. line terminal
L.V. line terminal
L.V. Neutral.
1. Impulse test voltage 1.2/50 micro second fully wave positive and negative polarity
1. Impulse test voltage 1.2/50 micro second fully wave positive and negative polarity
applied to:
H.V. line terminal
L.V. line terminal
L.V. Neutral m.
Weight of:
Iron core
Copper
The transformer shall be designed and manufactured in accordance with the
requirement of 8.S. 171:1970 equivalent.
4.12 LOW TENSION SWITCHGEAR:
SWITCHGEAR DESIGN:
The switchgear shall be pre-fabricated, complete and ready for erection
on the site.
The switchgear shall be totally enclosed. All line parts shall be
adequately and efficiently protected against accidental
touching.
Tine switchgear cubicles shall conform to relevant provisions of BS/IEC
and shall be adequate in all respect to accommodate the cables, switchgears,
meters, cable terminations and inter connection as indicated in the schedule/specification/drawings and be with provided
lockable doors. All apparatus and other components shall be
easily accessible from the front as required ,for inspection, replacement and repair. The switch gear shall be of
tropical design.
The Switchgear
shall conform to the specifications:
Operating
Voltage : 0.415KV, 3-phase at 50 Hz.
Voltage system : Direct
earth
Number of bus
bar : 5
(LI, L2, L3, N & E)
Rated current of
bus bars : As per schedule
Bus bar materials : Copper
Degree of
protection of busbar chamber : Enclosed
Maximum protective current
(cos Q - 0.2, t=0.1 sec) of busbar : 80KA
Maximum short time withstand current of busbar : 63KA
Maximum protective peak current of busbar : 150 KA.
All parts of the switchgcar including apparatus shall lie designed to
withstand without being damaged, the mechanical and
thermal, strain of this current or, where protected by circuit breaker, the
interrupting current of the circuit breaker.
Outgoing cables shall be arranged in separate specious cable spaces.
Protective screens shall, as far as possible, be arranged between main
busbars and cable space.
Terminals for power cables shall be protected against accidental
touching.
Interior control wiring shall be accommodated in plastic conduits.
Wiring inside the cubicles shall be made with minimum 0.75mm2 area and
with tinned copper conductors.
The Switchgear shall be suitable for busbar entry from the top, if
required as per schedule.
APPARATUS:
The switchgear shall be arranged in accordance with the attached
principle drawing.
The switchgcar shall be of modular type design. The apparatus of each
functional group shall be assembled on a common base.
Coils for
contractors must be of open type to be repairable.
CUBICLE CONSTRUCTION:
The distribution sections shall be of carcase construction and the
carcase shall be augmented with various cladding plates as
required.
The top plate, bottom plate and side plates shall be polled for easy
removal.
The door shall be IP23 for distribution sections and IP54 for bottom
plate respectively.
Creepagc and
clearance paths shall conform to VDE 0110 insulation group C or UL508 cable
18.1 and BS 162 table 4.
The electrical
equipment inside the panel shall be finger proof. The cubical shall be dust
vermin proof.
CABLE ENTRIES AND TERMINATIONS:
The distribution board shall be so designed that the cable are fed in
and connected in the base. The bottom plate shall be split
anil removable type to facilitate cable entry having cable grommet. All cable socket
for incoming and outgoing cable are to be provided.
CURRENT TRANSFORMERS :
All current transformers shall comply with IEC 185 /BS 3938 and shall be
of suitable class, raring and accuracy depending on the duty.
INDICATING LAMPS:
Panels shall
have indicating lamps as specified. AIR-CIRCUIT
BREAKERS/ MCCB :
The air-circuit
breakers / MCCDs shall comply with IEC 947,157 DS4752.
The breaker shall have spring assisted manual closing mechanism with,
breaker closing speed independent of operator. There shall be breaker closed
opened position indicator manual tripping shall be by push button and it shall
not be possible to trip the breaker by means of the closing mechanism. Over load release shall trip the breaker by means of the closing
mechanism. Over load release shall trip.
4.13 CIRCUIT BREAKERS:
The MCB/MCCB's shall be quick-make, quick-break, trip free, indicating
type and shall have inverse time limit characteristics with
adjustable overload, adjustable short circuit (the maximum adjustable limit should be as per schedule) and instantaneous magnetic trip elements
functioning on overloads above the normal operating
range. All circuit breakers shall be in accordance with schedule. All lugs must
be of the solder less above the normal operating range. The MCB
must comply with IEC 157-1, IEC 898 rated voltage 240/415V,
A.C 50 Hz. interrupting capacities minimum 6 KA current limiting class 3,
finger proof, protection through Thermal and Magnetic Trip
sections respectively, temperature rating 40 deg.C preferably tropicalized (moisture fungus corrosion treated), with
contacts of silver alloy, terminal capability as per
requirement. The MCCB must comply with 1EC 947, 157-1 having rated voltage 600V
A.C. 50 Hz with thermal overload and instantaneous
magnetic tripping action, temperature rating 40 deg.C preferably
tropicalized (moisture-fungus-corrosion treated), terminal capability as per requirement. The bidder may offer MCCB instead of MCB to meet
requirement of the specifications.
4.14 AUTOMATIC REACTIVE POWER CONTROL EQUIPMENT WITH CAPACITOR BANK:
The Power Factor Improvement Plant shall be sheet steel clad dust and
vermin proof free standing, floor mounting indoor
type. The centrally controlled automatic PFI Plant will be of compact design
and will be suitable for operation in 12 steps in the system for automatic
control of the reactive power. The PFI plant shall be consisting of 600KVAR,
415V, 50 Hz, self healing non-PCB, capacitor bank with disconnecting switch with fuses of proper rating, discharge
resistors required nos. suitably rated air-breaker contractors and associated control unit. The contractors shall
have special non-welding contacts which can control inrush current of upto 180
times the rated current. When the contractors drops out the resistors shall be switched on the capacitor by means of two break
contact. The control unit shall be an integral part of the PFI Plant and will be comprised of C.T. of adequate
rating automatic power factor correction relay to keep the automatic power indicating lamp ON/OFF
switches, switching step indicator etc. PFI panel shall be of a type conforming to IEC 439-1 from
manufacturer having ISO 9001. The automatic control must be non-responsive in a
certain range to element hunting.
4.15 BUSBAR TRUNKING SYSTEM
The low impedance prefabricated sand witch type main busbar trunking
system shall
conform to IEC 439/1-2, tested Siesmic standard shall be suitable for
use in installation conforming to IEC 364.
The busbar trunking system shall be comprising of (i) two piece
aluminium enclousurc (ii) Straight length (iii) Fixing brackets (iv) Elbows (v)
Bends (vi) closed type transformer connection unit (vii) distribution board connection
unit (viii) tap-off boxes with MCCB etc.
SPECIFICATION OF BBT SYSTEM:
Standard : IEC
439-1 & 2, KEMA certificate
Housing : 2-piece aluminium (no duration till
55deg. C)
Maximum ambient temperature: 40 Deg.C
Degree of protection : IP54
Colour : Approved
colour
Rated insulation
voltage : Maximum 600 V.A.C..
Frequency. : 50
Hz.
CAPACITOR:
The item includes supervision of
installation of capacitor on prepared foundation. The foundation is to be prepared by Contractor as per direction of the Engineer-in-charge /
Consultant. All consumables required to install the
equipment shall be supplied by the Contractor. After completion of the
installation the Contractor should test the equipment in presence of
Consultant to his satisfaction.
EARTHING SYSTEM:
The work under this item shall consist of supply and installation of
earth electrode with copper lead, earthing inspection pit and connecting to the
specified terminal according to the drawing, specification and direction of the Engineer-in-charge / Consultant. The whole
electrical system including light, fan, regulator sockets
sub-station and metal parts incorporated with building electrification shall be
earthed.
The earth resistance of the electrodes system shall be to the
satisfaction of the local supply authority and shall not exceed in one ohms.
Voltage to Earth
divided by 5 into Current rating of the
largest over Current protective device.
Materials :
Earth Electrode :
The earth Electrode in a 1 and 1/2" dia, G.I. pipe with
3/16th inch, dia drilled holes.
The G.I. pipe
shall be similar to the specification.
The pipe earth electrode shall be sunk and buried below ground level upto
its full length or as advise. The earth lead and be
connected to the earth electrode by brass/G,I. clamp. After
making connection the clamp shall be covered with bitumen poured hot and with
jute cloths.
Earth lead :
Earth lead shall consist of two numbers, 2 SWG high conductive
electrolytic bare copper .wire meeting the requirement of
B.5.S. 6360 :1969 and/or it's equivalent.
All earth lead shall follow the shortest and most direct route to the
earth electrode avoiding sharp bend and from inspection
pit to the entry at the building shall be enclosed in 1" dia
G.I. pipe. The earth lead shall be connected to test earth electrodes by
means of lugs, bolts, nuts and double washers to fixed as to
make permanent and positive connections both electrically and mechanically. The joints shall be covered with PVC compound without
disrupting the continuity.
Earth Inspection Pit:
Inspection pit shall have to be constructed over earth electrode to
inspect and test the connection terminals, bricks
used shall be of 1st class and only approved quality cement shall be used,
Jhama brick khoa for R.C.C. cover shall be 3/4th inch down graded and
washed, cleaned before casting. 3/8th inch dia MS. Rods @
4" c/c with two 1/2" dia M.S. Hook shall be provided in the cover
slab.
Installation :
Electrode:
The pipe earth electrode shall be sunk and buried below ground level upto
its full length or as devised bv the Engineer-in-charge /
Consultant. The earth leads shall be connected to the earth electrode by silicon aluminium bronze body clamp and phosphor bronze screws. After
making connection the clamp shall bo covered ivith bitumen poured hot and with
jute cloth.
Lead :AI1 earth lead shall follow the shortest an most direct route to
the earth electrode avoiding sharp bend and from
inspection pit to the earth electrode avoiding sharp bend and from inspection
pit to the entry at the building shall be enclosed in 1" eiia
water grade PVC pipe. The earth lead shall be connected test eartli electrodes
by means of lugs, bolts, nuts and double washers of failed as to make permanent
and positive connections both electrically and mechanically. The joints shall
be covered with PVC compound without disrupting the
continuity.
Pit:
1st class brick
made inspection pit and RCC cover with Sub-Station & Diesel Generator Set
Set hook shall be built on earth electrode
as described here above at the location shown on the drawings the
electrode shall be within lO'-O" from the building.
Maximum Earth Loop Resistance :
The maximum earth loop resistance any point in the installation including
earth lead to the earth electrodes shall not exceed the resistance specified in
the schedule or that indicated by the Consultant. The contractor must ensure that the leads are efficiently bonded to all
metal work other than the current carrying parts. So
that the above resistance level is not exceeded. It will be the duty of the
contractor to provide earth tester, lest the installation in presence of the
authorized representative of the authority and submit earth
test report to the authority for approval.
Method of Measurement: Measurement shall be per set of earthing system installed.
4.16 GENERATOR:
DIESEL ENGINE Driven A.C. generator set having a prime power output as
per schedule {continuous rating) standard
voltage 230/415 volts, 3-phase, 50Hz, 4-wire at 1500 rpm under condition of
normal temperatures and pressures. The manufacturer must have
ISO9001.
GENERAL DESCRIPTION:
The engine and alternator assembly shall be directly
flanged coupled, the alternator being driven by a flexible coupling connecting engine fly wheel to
alternator rotor.
The unit should be mounted together with cooling radiator
on a fabricated, heavy steel frame of all welded
construction designed to accurately align and support the assembly. The base
frame is to be predrilled to allow for ant vibration mounts and is to be
provided with special Sub-Station & Diesel Generator Set Setting arrangement for case of handling and safety
purposes.
There must be arrangement for manual/ automatic battery
electric start being operated from the main control pano-1 which
shall also include all monitoring and protection devices covering the
mechanical and electrical systems.
DETAILED
SPECIFICATION:
Diesel engine driven generating set having a continuous
rated output at 0.8 Power factor at 415/230 Volts,
3-phase, 4-wire, 50Hz at 1500 RPM under conditions of normal temperatures and
pressures with 10% overload for one hour at conditions
specified under B.S. 5514, DIN6271, ISO 3046/1.
ENGINE:
The engine shall be of 6 cylinders, 4 stroke, Air to Air
after cooled, turbocharged, pressure lubricated, direct injection, water
cooled, industrial tvpe Oiesel engine developing the rated bhp at 1500 RPM, at NTP conditions.
'line engine shall be complete with close control
governing to BS 5514, 1979 Class AT Fuel Injection equipment with :
Fuel oil filters , Lubricating
oil filters ,Air
cleaners/filters Fuel solenoid
energized to run,
Lubricating oil pressure pump, Water circulating pump, Battery charging generator, Precision mechanical governor, Starter motor, Fuel solenoid, Thermostatically
controlled by pass system.
ENGINE
STARTING:
The engine shall be fitted with manual automatic electric
starting by means of a starter motor arranged to engage with the fly wheel.
ENGINE COOLING:
The diesel engine shall be cooled via a tropical air
blast heavy duty radiator with engine
driven pusher tvpe fan, complete with water circulating pump,
radiator guard, thermostat and by pass system.
BATTERIES :The unit shall be supplied with a set of suitably rated
heavy duty 12/24 volt industrial type lead
acid batteries (dry charged). A mains operated battery charger should be
mounted in control cubicle.A set of
starter cables and connections would be supplied loose.
LUBRICATING
SYSTEM :
Wet sump force feed lubrication system by gear driven oil
pump incorporating replaceable oil filters.
EXHAUST
SYSTEM:
The engine shall be supplied with :-
Acoustic type silencers, flexible bellows sections and
rigid exhaust pipe of suitable length, suitable for use with Vee form engine,
supplied loose for site erection. The complete exhaust system shall be designed
to 'prevent any de-rate of the engine due to excessive back pressure. All
exhaust components are to be finished with heat resistant paint.
ALTERNATOR:
Brushless Salient pole rotating field, self-exciting,
self-regulating, single bearing construction with integral automatic voltage
regulator providing voltage control to within +/- 2% of nominal range, no load
to full load and at all power factors between unity and 0.8 lagging and with a
maximum 5% prime mover speed variation. Class
1 insulating on both rotor and stator windings and with enclosures to iP21 of
BS 4999 Part 20, 1EC & DIN
standards. The alternator meets the requirement of BS 5000 and radio
suppression to BS 800 & VDE
class" G&N.
ANTI-VIBRATION MOUNTINGS:
A set of anti-vibration mounts and spring isolator would
be supplied loose for positioning beneath bed frame when the side is delivered to site. These have their own in - built
leveling device and friction pad, therefore fixing to the
floor is not necessary.
FUEL SYSTEM:
The unit shall be supplied with a base mounted fuel tank
in corporate in the base frame of the unit providing sufficient fuel for 8
hours continuous full load operation, the base shall be pressure tested prior
to assembly and will incorporation dial type content/gauge, filler cap, vent
pipe, drain cock and all necessary fuel
connections. All pipe terminations shall be completed during works assembly.
The system shall include arrangement for low and high level alarm system of
fuel. An additional daily fuel tank (self Standing) of "1500
liter capacity with automatic supply type including level switch & pump.
FUEL
TRANSFER:
A set of rotary type hand pump would be supplied with 3
meters of flexible pipe, suitable for manual fuel transfer to the daily service
fuel tank.
COUPLING:
The alternator casing would be flange mounted to the
engine flywheel housing and the
rotor shaft, coupled to the engine flywheel through a
flexible element to minimize tensional vibration throughout the operating range,
BASE FRAME:
The engine and alternator would be mounted on a
fabricated steel type base frame of welded construction adequately designed to resist bending and tensional
forces. The base frame shall accurately align and support the assembly and shall provide Sub-Station &
Diesel Generator Set Setting points and location points for securing to the
foundation.
SWITCHGEAR:
Switchgear and instrumentation shall be mounted in
totally enclosed, stove enameled sheet steel, set mounted control panel fixed to the saddle frame of the
alternator by means of rubber anti-vibration mounts. The panel shall have provision for BBT connection. The control
panel would have access to all internal components and include the following:
1- OFF/MANUAL/AUTO selector switch.
1- Frequency Meter.
1- Volt meter (0-500V) with selector switch (six
positions)
1- Ammeters (0-1000A) with selector switch.
1- 1000A
TP circuit breaker with adjustable thermal and adjustable magnetic trips.
1- Battery charger indicator with ammeter.
1- Key start switch
1- Hour run recorder
1- Set of relays and timers
1- Set
of cartridge type fuse
1- Set of output terminals
1- Sot of indicator lamps for fault indication of Low
Oil pressure, High Engine Temperature Gauge,
over speed, Overload and reverse Power relay, over crank.
1- Fault protection reset switch and 1- buzer to draw
attention.
The Control Panel would be complete with all internal
wiring cables and accessories necessary for satisfactory
operation and maintenance. The control system should be manually reset once the
fault is rectified. All the failure
circuits must incorporate a "Press to Test" facility which when
operated will remove the fault and shut the generating plant down.
ENGINE
INSTRUMENTATION:
Incorporated in the control panel or mounted on a separate
engine mounted panel, our option, shall be the
following engine instrumentation:-
1- Oil Pressure gauge.
1- Water Temperature gauge.
1- Hours run recorder.
BONNET & SOUND
PROOF CANOPY (600 KVA Generator):
Should be fabricated by heavy duty steel structure
covering with steel sheet. The inner side of the steel enclosure should be lined with sound absorbing materials
which should be covered by perforated steel sheet. The sound
reducing level should be 82 dBA @ 1 meter from the canopy.
GENERATING SET PROTECTION :
The unit shall be arranged to automatically shutdown and
indicate the same in the event of:
Fail to start
Low
oil pressure
High engine temperature
Engine over speed
Overload
Over/under voltage protection
FINISH:
The generating set would be finished in Hammer
blue/Yellow and the control panel in grey/Yellow.
HAND BOOKS:
The equipment would be supplied with: i.
Operation & maintenance manual.
ii.
Engine & alternator parts catalogue. TOOLS:
One set of standard routine maintenance tools would be
supplied in a tool box.
AUTO CHANGE OVER SWITCH:
At the event of mains failure, an energy stop switch
should be attached with the Alternator body, the generator shall start or if supply voltage goes below specific level or
single phasing automatically and change
over to the load. With restoration of main supply the generator shall shunt
down automatically as well as the load
shall be transferred to the normal supply. The bidder must mention the change
over time in seconds. The supply and installation of generators with automatic
change over switch shall be on "turnkey basis' and shall include the cost of:
Taking necessary permission from the relevant of
authority. All pipe works.all inter connecting power and control cable works. Daily and reserve fuel tank including the transfer pump.
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