MAIN TENDER REFERENCE NO - SRFT19080138
SECTION 14 : STANDBY GENERATING PLANT
14.1
General
14.1.1
Description
a.
This section of the Specification covers the design, supply,
installation, testing, commissioning and setting to work of complete
generating plant as shown and as specified herein. The standby
generating system shall include, but not be limited to, the followings:
(i)
complete diesel engine/generator set including radiator, antivibration mountings, holding down bolts, etc.;
(ii)
complete exhaust system including all silencers, suspension
and thermal insulation;
(iii)
complete fuel delivery system including a daily service tank,
all pipes, valves, feed pump and pipe works where required
and as specified on the Specification & Drawing;
(iv)
control panel complete with all accessories, monitoring
auxiliaries contact and control, to provide a complete and
operable system;
(v)
DC electric starting system.
(vi)
Complete generator control system complete with sensing
cable, control cable, control auxiliaries control and cable
supporting system.
(vii)
Acoustic Treatment
b.
The generating plant shall have provision for both manual and fully
automatic starting facilities, and be capable of accepting the
designed connected load in the event of a complete mains failure,
and to do so in not more than 10 seconds. This is applicable to single
or multiple generating plants.
c.
The generating plant shall be adequately sized to meet the load
requirements under worst case considerations given on the
specification and drawings. Details of the sizing shall be submitted
for approval. The sizing of the generating plants shall consider, but
not be limited to the following factors:
(i)
derating factors (altitude, ambient temperature, power factor,
etc.);
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(ii)
impact load;
(iii)
transient voltage dip;
(iv)
momentary overload;
(v)
re-generative power;
(vi)
rectifier loads;
(vii)
phase loads unbalance;
(viii)
instability due to interaction between voltage regulation
systems (e.g. AVRs of generating plants and UPSs); and
(ix)
a 10% overload capacity in excess of the nameplate
continuous rating for one hour in any of twelve (12)
consecutive hours of full load operation.
Notwithstanding the above, the generating system shall have a
minimum full continuous rating as indicated on the specification and
drawings.
14.1.2
14.1.3
Particular Requirements on Quality Assurance
a.
The manufacture of various components and accessories shall be as
recommended by the generator manufacturer to ensure compatibility
of the components.
b.
Notwithstanding any description or detail (implied or otherwise)
included hereafter and on the specification and drawings, the
generating plant and the final installation shall comply with the
statutory obligations, local requirements and Singapore Standard SS
535
c.
The Contractor shall be responsible for co-ordination and guarantee
of the overall performance of the generator, driver, gears and all
auxiliaries.
Submittals
As a minimum, the following shall be submitted for approval at the
appropriate stages of the Works:
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a.
detailed schedule of equipment and components and manufacturer's
data, including fuel pipe insulation material, selection of engines,
alternators, sizing of radiator, sizing of vibration isolators both for the
engine as well as for the pipes hangers.
b.
general layout of the generator set, control panel, fuel tanks,
pipework, exhaust outlets, etc. which is to be consistent with the size
of the generator plantroom;
c.
detailed and co-ordinated working drawings on Generator Room
equipment layout, with requirements on engine exhaust system, fuel
supply system, cooling system; including calculations, pipe sizes,
construction details, installation details;
d.
electrical control wiring diagrams showing details of all wirings
internal and external to the generator control panel, together with
terminal numbers for cable terminations to external equipment;
e.
detailed calculation on battery sizing;
f.
equipment weight;
g.
builder's works requirement;
h.
proposal on testing procedures and report format for testing of the
generating set at the manufacturer's works and on site;
i.
torsional calculation from the supplier:
j.
site installation procedure and;
k.
testing and commissioning procedures
l.
generating plant / room airflow calculation
l.
current transformer CT selection calculation
l.
generator vibration mount / spring isolator calculation endorsed by
Professional Engineer,
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14.2
Product
14.2.1
General
a.
The generating plant shall comprise a diesel engine generator
mounted on a common base skid and complete with factory supplied
anti-vibration resilient mounting.
c.
All exposed moving parts, except manually operated controls, shall
be totally enclosed or guarded to prevent contact by personnel.
d.
All exposed surfaces which are sufficiently hot to cause injury shall
be adequately guarded.
e.
All exposed ferrous metal surface of the generating set, underframe
and ancillary equipment shall, where applicable, be treated with rustproofing primer paint undercoat, with the finishing coat to
manufacturer's standard.
f.
The following service conditions shall apply:(i)
Ambient Temperature
-
Maximum design 40°C
Minimum design 19°C
g.
(ii)
Ambient air which may be salutiferous, with relative humidity
of not less than 90% shall be taken into account.
(iii)
Altitude - 1000 metres or less above sea level .
Electrical Characteristics
(i)
Normal System Voltage
:
400 volts, 3 phase, 4 wire
(ii)
Frequency
:
50 Hz
(iii)
System Neutral
:
Solidly ground
(iv)
Control Power
:
DC 24V
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h.
Diesel engine and generator shall be installed on a common
baseplate as one assembly.
i.
The generator plant is normally at rest in a standby mode and is
automatically started on failure of the utility system.
It shall be
suitable for continuous operation as an emergency power source.
j.
Basis of Rating
k.
14.2.2
(i)
The diesel engine generator set shall be rated on a
continuous duty basis and the continuous rating shall be
expressed in KVA available at the generator terminals at 0.8
power factor.
(ii)
The excitation shall be able to support 300% of full load
current over 10 seconds. The rated voltage shall be 120% of
generator field voltage required at rated output of the
generator.
The generating plant control panel shall be floor mounted type free
from vibration of generator during operation.
Diesel Engine
a.
Engine Performance and Type
(i)
The engine shall be rated for continuous operation and
suitable for driving the electric alternator as specified
hereinafter. The performance of the engine shall comply with
SS 535 and BS ISO 3046-1.
(ii)
The engine shall also be capable of driving the alternator at
10% overload for a period of one (1) hour in accordance with
the requirements of SS 535 and BS ISO 3046-1.
(iii)
The engine shall be direct injection, cold starting, water
cooled, pressure lubricated, four stroke and single acting
compressor ignition diesel engine conforming with the
performance requirements of BS ISO 3046-1.
(iv)
The engine shall be suitable for running on diesel of BS 2869
Class A2 or equivalent.
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(v)
The engine shall be of the naturally aspirated type.
(vi)
The engine shall be rated for continuous duty to BS ISO
3046-1 and sized to match the continuous rating of the
generator with overload capacity as specified hereafter.
(vii)
Engine crankshaft speed shall not exceed 1500 rpm. The
normal direction of rotation shall be anti-clockwise.
(viii)
The engine shall comply with emission standards minimum
of EU Stage II, US Tier II or Japan Tier I or better. NEA letter
of compliances shall be submitted.
(ix)
Accessories mounted on the engine shall include but not
limited to the following:

Speed Governor

Overspeed Trip Mechanism

Hours Run Counter

Tachometer

Lubricating Oil Pump

Exhaust Outlet, Oil and Water Thermometer

Alarm System

Oil Pressure Gauge

Temperature Gauge
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b.
c.
DC Electric Starting System
(i)
The generating set shall be equipped with an engine starter
motor which shall be suitable for 24V DC operation, complete
with manual and automatic starting and starter cut-out switch
as described herein.
(ii)
The engine starting control equipment shall be arranged to
disconnect the mains operated battery charger to prevent it
being overloaded during starting.
(iii)
The starter motor shall be of adequate power for its duty and
of "non-hold-on" type in which the piston is moved axially to
engage with a gear-ring on the engine flywheel before the
starter motor is fully energised. The pinion shall positively
disengage when the engine starts or when the motor is deenergised.
(iv)
The starting equipment shall incorporate a fail-to-start device
for automatically disconnecting the starter motor if the engine
fails to start within a pre-determined time, say 15 seconds, so
as to avoid undue discharge of the batteries.
(v)
A total of three (3) consecutive starts, say with 15 seconds
duration, shall be made to start the engine, after which
disconnection of the starter by the fail-to-start device shall
operate the visual and audible alarm as specified hereafter.
No further attempts shall be made to start the engine by the
automatic starting system until the fail-to-start mechanism
has been reset manually.
Batteries and Chargers
(i)
A 24V DC engine starting battery set of nickel- cadmium type
of adequate ampere hour capacity and discharge rate. The
battery shall comply with BS EN 60623, IEC 60623 and be
capable of providing three thirty second cranking time without
recharging. The Contractor shall submit full calculation of the
battery capacity for Engineer’s approval. The battery shall
be housed in a corrosion resistant container of an approved
type.
(ii)
The Contractor shall also supply, delivery and install a
separate battery set of maintenance free nickel - cadmium
type of adequate ampere hour capacity and discharge rate
for the purpose of DC shunt trip and other protection circuits.
The Contractor shall submit full calculation of the battery
capacity for Engineer’s approval.
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14.2.3
(iii)
The battery charger shall be constant potential type,
complete with DC voltmeter and ammeter, surge suppressor,
controls, float and boost charging selection, battery
discharging indication, protection against over-charging and
indication and charger failure alarm. All controls and sensors
shall be wired to the set control panel.
(iv)
The Contractor is to provide steel battery racks. They shall
be painted with two coats of electrolytically resistant paint.
The racks shall be properly arranged for easy maintenance
and installation.
(v)
A battery disconnect switch mounted on a board/panel shall
be provided and of which shall be capable of safely
interrupting the short circuit current of the battery.
Alternator
a.
b.
Enclosure
(i)
The alternator shall comply with the requirements of BS
5000-3 and have dimensions and frame size in accordance
with BS 5000-3. The housing shall be drip proof to IP 23 of
BS EN 60947-1 screen protected and have axial flow forced
air ventilation and rated to provide the nett output and
overload capacity as specified.
(ii)
The alternator shall be built in with thermostatically controlled
heater and with manual isolating switch at the control panel.
Alternator Performance
(i)
The alternator must be capable of withstanding an overspeed
of 20% above synchronous value for 2 minutes without
mechanical damage or permanent distortion. Mechanical
protection of the alternator against overspeed effects shall be
provided by the engine overspeed protection devices
specified.
(ii)
The alternator must be capable of withstanding an unbalance
load with the current in one (1) phase more than the other
phases by 60%.
(iii)
The alternator shall withstand three (3) phase short-circuit
conditions without damage. Excitation shall be maintained
under external short-circuit fault conditions to produce a short
circuit current of three (3) times full load. The field shall be
suppressed under internal fault conditions by direct field
suppression on slip ring machines or by suppression of the
excitor field on brushless machines.
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(iv)
Steady state voltage variations shall not exceed +1% from no
load to full load. The alternator set shall be capable of
supplying its rated KVA output at rated speed and power
factor at voltages ranges from +2% to -2% at rated value.
(v)
The alternator set shall be capable of supplying its rated KVA
output at rated voltage and power factor at frequency ranging
from +2% to -2% at rated value.
(vi)
Its excitation system shall be designed to withstand a 10%
overload for one (1) hour at rated voltage, speed and power
factor without dangerous temperature rise.
(vii)
The alternator set shall be capable of withstanding for 15
seconds a current 50% in excess of its rated current with the
field set for rated load excitation.
(viii)
The alternator set shall be capable of withstanding 150% of
rated current at its terminals for 15 seconds without damage
when operating at rated KVA and power factor with fixed
excitation.
The machine phase currents under fault conditions are such
that the negative phase sequence current, (In) expressed in
per unit of stator current at rated KVA, and the duration of the
fault in seconds, t, are limited to values which given an
integrated product.
(In) x (In) x t equal to or less than 40.
The maximum phase current is limited by external means to
a value which does not exceed the maximum phase current
obtained from a three-phase fault.
(ix)
The deviation factor of wave from of the open-circuit line-toline terminal voltage of alternator shall not exceed 0.1.
(x)
For sudden applied load conditions, recovery of stable
condition shall start within ½ second and frequency
regulation shall not exceed 2 Hz from no load to rated load.
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c.
d.
Alternator Type
(i)
The alternator shall be brushless, self-exciting, selfregulating type, continuously rated to BS 5000-3. It shall
have a conventional stator and salient pole revolving field
system incorporating on a common shaft, the armature of the
AC excitor and a three (3) phase full wave silicon diode main
field rectifier. Each diode shall be provided with fuse
protection. The alternator shall be self-excited from its output
terminals through a static automatic voltage regulator.
(ii)
The windings shall be suitably insulated and impregnated for
operation in tropical climates and adequately braced to
withstand short circuit forces. The rotor shall be of the
salient pole type with fully interconnected damper windings.
The stator windings shall be star connected with neutral
connections brought out and labelled A-B-C for phases and
a-b-c for neutral ends.
(iii)
The alternator characteristics must be matched to the torque
characteristics of the engine, in such a manner that with full
load connected to the alternator, it can utilize all the available
engine power without exceeding it.
(iv)
The stator windings shall be star connected with the neutral
terminal brought out and solidly earthed.
(v)
Insulation to prevent shaft current flow shall be provided for
the alternator.
Insulation
The rotor winding shall be Class F (155°C) and the stator and excitor
windings shall be Class E (120°C) suitable for use in local condition/
climate. The stator and rotor windings of the alternator and excitor
shall have oil, acid, moisture resistant Class F thermosetting
insulating varnish with a final/heavy insulating coat of air drying and
anti-tracking varnish.
e.
Bearings
The alternator shall be fitted with heavy duty double ball or double
roller bearings which shall be pre-packed with suitable lubricant for
life.
f.
Automatic Voltage Regulator
(i)
A rapid response automatic voltage regulator shall be
provided to regulate the generated voltage.
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(ii)
The voltage control unit shall be mounted in the control
panel. Automatic voltage control if provided by a solid state
unit shall have a frequency sensing device to prevent
overloading of excitor components during under speed
conditions. Manual voltage control with an auto/manual
selector shall also be provided. The voltage regulator
sensing device shall be a three (3) phase type and shall
respond to average voltage output and not peak voltage
output.

Steady State Condition
Under the steady state condition, the automatic
voltage regulator or any other voltage stabilizing
system shall be capable of maintaining the voltage to
within +2.5% of its set value for all loads between no
load and rated load, including cold to hot variations
and load power factor between 0.8 lagging and unity.
The load conditions shall also include out of balance
loading of up to 10% between any two (2) phases.
Following transient changes, the voltage shall be
restored to within these limits in less than 10
seconds.

Transient Condition
The excitation system shall be designed to promote
rapid voltage recovery following sudden application
or disconnection of load. The voltage shall recover
to within 2.5% of the steady state value within 0.3
second after the application or disconnection of load
up to the rated load.

Transient Voltage Rise
The voltage shall be arranged to fall off with
excessive reduction of engine speed. The transient
voltage dip or rise upon the application or rejection of
the load up to the rated load shall not exceed 20%.
g.
Radio Interference
The whole of the equipment shall be efficiently protected against
emission of electromagnetic interference.
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h.
Temperature Rise
The temperature rise shall be in accordance with BS 5000-3 for the
appropriate insulation Class in a 40°C ambient.
i.
Waveform
The voltage waveform of the generating set shall be as close as
practicable to a sine wave both at no load and at full load with a
power factor of at least 0.8 lagging. The line to line voltage waveform
shall be in accordance with BS 5000-3 and the total harmonic
distortion shall not exceed 5%.
Three (3) copies of oscillograms of the voltage waveform taken shall
be provided.
14.2.4
Radiator
a.
The engine shall be water cooled by means of a matching heavy duty
radiator complete with belt-driven fan, coolant pump, thermostat
temperature control liquid-cooled exhaust manifolds, intercooler,
coolant corrosion resistant filters suitably designed to suit the site
conditions.
b.
The radiator shall be mounted on the same base skid supporting the
generating set where a set mounted radiator is required.
c.
The radiator fan shall be suitably selected with sufficient fan static
pressure to overcome pressure losses through the fresh air intake
acoustic louver-wall, radiator, silencers, ducts, exhaust plenum box,
exhaust tunnel and aluminum louver. The air flow quantity shall be
sufficient for engine combustion, removal of heat generated by the
complete generating set operating at full rated load and radiator
cooling as recommended by the generating set manufacturer.
d.
The radiator shall be fitted with duct adapter flange to enable the
ventilation ductwork to be attached to the radiator. A short section of
ductwork shall be installed between the radiator and the metal
louvres provided. Ductwork shall be constructed of galvanized steel
sheets in accordance with SMACNA construction standards. Gauge
of sheet metal of ductwork shall be in accordance with the
recommendation of ASHRAE with G115 designation zinc coating to
ASTM A653 / A653M-11. All ductworks shall have air-tight joints.
e.
The fan rating shall be adequate to allow for the additional resistance
of airflow to the ductwork and louvres fitted.
f.
Corrosion inhibitor shall be added to the cooling system.
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h.
14.2.5
14.2.6
Automatic shutdown of the generating set through overheating shall
be incorporated. A visual audio indication shall be provided on the
control panel to indicate the generating set has shut down due to
overheating coolant. Status indication for radiator fan shall be
provided at the control panel.
Coupling Arrangement and Anti-Vibration Mountings
a.
The diesel engine shall be direct coupled to the alternator which shall
be of the single or two bearing type.
b.
Anti-vibration units shall be mounted below the baseplate, or
between the generating set assembly and the baseplate, so that the
complete installation can be located on a solid concrete floor without
transmitting vibration to adjacent apparatus or any part of the
building.
c.
Vibration isolation equipment for the generating set shall comprise of
unhoused steel springs in series with two (2) layers of 8mm thick, 40
durometer neoprene waffle pads and 63mm minimum total static
deflection.
d.
A rigid base frame suitable for point mounting of isolators shall be
provided. There shall be no rigid ties to the structure. All conduits
and pipework are to be looped or flexible. Limit stops or restraint (out
of contact during normal operation) are to be fitted to the base to limit
transient movement during stops/starts.
Exhaust Silencers and Fuel
a.
A residential type silencer shall be provided. The silencer shall be of
chambered construction, complete with moisture trap, exhaust drain
and adequately sized to assure proper operation without excessive
back pressure when installed. The silencer shall be designed to
reduce the emitted noise to a level of 70 dBA measured at a distance
1m from the exhaust outlet.
b.
Stainless steel flexible bellows connectors and adapter, sized to
match the engine and exhaust silencer, shall be provided for
installation between each engine and the associated silencer.
c.
A fuel pipe complete with flexible bellows connectors, all adequately
sized, shall be connected beyond the silencer to discharge the fuel to
the location as shown on the Specification & Drawings.
d.
Bends in fuel pipe shall have a minimum radius of three (3) times the
diameter of the pipe.
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14.2.7
14.2.8
14.2.9
e.
The finish of all fuel pipework and silencers shall be aluminium
cladding of not less than 0.6mm thickness.
f.
The entire system shall be supported by spring type hangers with an
approved design.
Lubrication System
a.
Lubrication shall be by pressure lubricating oil system with engine
driven oil pump throughout the whole engine in conjunction with the
built-in oil-to-coolant heat exchanger. Multiple full flow filters with
renewable elements shall be provided. Automatic shut down of the
generating set through low lubricating oil pressure must be
incorporated. A failure warning light shall be provided on the control
panel to indicate that the generating set has shut down due to low
lubricant pressure. Oil pressure gauge shall be incorporated.
b.
Main, crank pin and camshaft bearings together with the valve gear
shall be lubricated by a gear type pressure pump feeding from a wet
sump. An audio signal alarm which shall remain on until they are
reset manually shall be provided. An oil temperature stabilizer shall
be provided.
Governor
a.
The engine shall be fitted with an electronic speed sensing governor
to provide steady running at any load within the rated load range.
Cyclic irregularity and angular deviation of the engine complete with
the direct coupling to the generator shall be equal or better than the
requirements as laid down in BS ISO 3046-4:2009.
b.
The governor shall be of the centrifugal type integral with the fuel
injection pump. A speedometer must be provided and automatic shut
down of the engine through overspeed must be incorporated.
c.
A failure warning light and an audio signal alarm shall be provided on
the control panel to indicate that the generating set has shut down
due to over speed at 110% of rated speed. They shall remain on
until they are reset manually.
Fuel Service Tank
a.
A fuel service tank shall be to BS EN12285-2:2005 and of 1000 litres
capacity as shown on Specification & Drawings. The tank plate shall
be of carbon steel to BS EN 10025-1.
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b.
14.2.10
14.2.11
Tank shall be of welded construction and welding shall be carried out
by the electric arc method. Electrodes shall be hermetically sealed
and shall be supplied together with welding schedules indicating the
run and type of electrode to be used. Each tank shall be supplied
with all necessary fittings and connections including the following:
(i)
roof manhole and hinged cover;
(ii)
glass type and/or dial type visual level indicators marked in
litres;
(iii)
earth terminal near base of tank;
(iv)
drain valve and pipe;
(v)
copper vent pipe connecting to a goose neck with stainless
steel wire gauge covered opening;
(vi)
isolating valve;
(vii)
remote leakage indicator; and
(viii)
high and low level alarm.
Engine Heater
a.
A water jacket heating system shall be provided to maintain the
engine jacket water to about 30°C or as recommended by the
manufacturer, so as to ensure ease of starting on demand.
b.
The heater shall be thermostatically controlled and be disconnected
whenever the engine is put into operation.
Miscellaneous
a.
Fuel Injection System
The fuel injection system shall be complete with primary and
secondary fuel filters with replaceable elements, and an engine
driven, mechanical, positive displacement fuel pump, all mounted on
the engine.
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b.
Lubricating System
Enclosed forced feed lubricating system shall be complete with
positive displacement, mechanical lubrication oil pump, lubricating oil
cooler, filters and dipsticks oil level indicator.
c.
Air Cleaner
Replaceable dry element air cleaner shall include an automatic
device to give an alarm when the filter becomes clogged.
14.2.12
14.2.13
Positions of Control and Adjustment Devices
a.
All operational controls shall be arranged such that they are grouped
together in a readily accessible and logical position.
b.
Setting up devices shall
unauthorised adjustment.
be separately located to prevent
Engine Status Indication
The engine shall be provided with the following status indication as a
minimum:
14.2.14
a.
oil pressure;
b.
oil temperature;
c.
engine temperature;
d.
service hours;
e.
tachometer; and
f.
battery charger ammeter.
Engine Protection
a.
The engine shall be provided with the following protective devices
and control as a minimum to effect early warning and/or shut down in
the event of:
(i)
low lubricating oil pressure;
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14.2.15
(ii)
high engine coolant temperature;
(iii)
low coolant level;
(iv)
engine overspeed;
(v)
engine overcrank; and
(vi)
low fuel level.
b.
The above protection shall be in two (2) stages; it shall give visual
and audible warnings at an initial stage and shall shut down the
engine when a pre-determined danger level is reached.
c.
All visual alarms, audible alarms and the associated muting switches
shall be wired to the control panel.
Voltage Regulation and Adjustment
a.
b.
Voltage Regulation
(i)
An automatic voltage regulation system shall be provided to
maintain the output voltage at the generator's terminal to
within +1% of its rated value from no load to full load under
steady state condition.
(ii)
The performance of the voltage regulation system of the
generator shall be of Grade VR2.23 as specified in BS 4999140.
Voltage Adjustment
A means of adjusting the output voltage shall be provided to facilitate
adjustment of the machine output voltage at any level within its
design parameters.
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14.2.16
Synchronising Control Panel
a.
Construction
(i)
The control panel shall be suitable for floor, wall or engine
mounted as indicated, in the form of totally enclosed, selfcontained, flush fronted cubicles containing the equipment
detailed. If it is floor mounted, it shall be provided with a
100mm channel base.
(ii)
It shall be manufactured from sheet steel of minimum
thickness of 2.0mm in all folded and welded construction. It
shall have provisions for hoisting and be dust and vermin
proof.
(iii)
The control panel shall be arranged for front access wiring.
Access of equipment shall be by means of hinged and
lockable lift-off access doors fitted with Neoprene seals.
Doors shall be provided with lift-off handles. The control
panel shall be provided with a removable plate on the top
complete with knock out holes, together with all other
necessary brass glands and supports to enable incoming
and outgoing cables to be installed and terminated.
(iv)
All surfaces shall be smooth and free from burrs, weld marks
and sharp edges.
(v)
The whole of the control panel metal structure shall be
thoroughly cleaned and degreased and the surface prepared
for painting by treating with an approved cleaning solution
such as Spartan Deren 'A'. The panel shall then be filled and
spray painted on all internal and external metal surfaces with
at least two coats of approved primer and brought to a fine
smooth finish free of all imperfections. Finally apply four thin
wet finishing coats avoiding orange peel effect and
compound to a high quality finish. The total paint thickness
shall be at least 45 microns.
(vi)
Special care shall be taken to achieve thorough bond
between the metal and all coatings. Internal and external
surfaces shall be to colours approved by the Engineer prior
to commencing manufacture of the control panel.
(vii)
Where electrical apparatus is attached to lids or doors,
means shall be taken to ensure continuity of the protective
circuit in the form of an earth continuity conductor of an
appropriate size.
(viii)
Wiring to apparatus and measuring instruments in covers or
doors shall be installed such that no mechanical damage can
occur as a result of movement of the door or cover.
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(ix)
b.
Adjustment devices not required on a regular daily basis
shall be so located to permit safe operation and shall be
housed in a separate compartment.
Generator Set Overcurrent and Earth Fault Protection
The generator set shall be provided with overcurrent and earth fault
relays complying with BS EN 60255 / IEC 60255 and shall have the
following characteristics:
Relay
Type
Make
Overcurrent
IDMTL
Earth Fault
DTL,
Restricted
Earth Fault
High impedance
instantaneous
(voltage operated)
The Contractor shall provide and install external shunt resistor for the
restricted earth fault protection to achieve the primary fault setting of
10% to 30% full load current.
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The Contractor shall also provide and install current transformers to
achieve the above protection schemes. The CTs shall be rated in
accordance with BS EN 60044-1, IEC 60044-1 and as follows:
Protection Scheme
CT Ratio
Class
Burden
Overcurrent and
Earth Fault
Protections
As shown in the
Specification &
Drawings
5P10
20VA
Restricted Earth
Fault
As shown in the
Specification &
Drawings
‘X’
-
The knee point voltage of Class X CT shall be selected such that it is
three times the final voltage setting of restricted earth fault relay.
The Contractor shall submit calculation to justify the suitability of the
current transformer for the protection scheme, taking into the
consideration of the burden of the protection relay, CT, cable, any
accessories and etc.
c.
Apparatus Equipment and Accessories
The control panel shall contain, but not be limited to the following:(i)
Four (4) pole circuit breaker with shunt trip facility, adjustable
trips for generator overcurrent, earth fault and reverse power
relays, controls and indications as specified. The current
rating and breaking capacity of the circuit breaker shall be
compatible with the generator provided;
(ii)
voltmeter, flush mounting, hermetically sealed, moving iron,
with fuses;
(iii)
voltmeter standby mains selector switch, phase to phase
switching;
(iv)
ammeter, flush mounting, hermetically sealed, moving iron,
with current transformers c/w half-hour maximum demand
indicator;
(v)
ammeter phase selector switch;
(vi)
frequency meter;
(vii)
power factor meter;
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(viii)
hours counter;
(ix)
kWH meter;
(xi)
restricted earth fault protection relay;
(xii)
overcurrent IDMTL protection relay;
(xiii)
current transformers for protection;
(xiv)
voltage sensing units to detect failure of any phase of the
normal mains supply;
(xv)
duty selector switch (Off/Test/Manual/Automatic);
(xvi)
engine 'START' and 'STOP' switches;
(xvii)
set of 'MAINS ON', 'STANDBY ON' and 'MAINS FAILURE'
indicator lamps;
(xviii)
fault reset button;
(xix)
shutdown relays, indicating lamps and audible alarm bell for:-
(xx)

engine low oil pressure;

high water temperature;

engine overspeed;

engine overcrank; and

low fuel oil level.
Solid state time delay circuits for:
delay on start, adjustable from zero to 10 seconds;
and

delay on restoration, adjustable up to 30 minutes.
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d.
(xxi)
Automatic battery charger - trickle and boost;
(xxii)
HRC fuses for control circuits and instruments; and
(xxiii)
Any other equipment required for the proper operation of the
system or indicated in the Specification & Drawings.
Wiring and Terminations
(i)
Wiring for mains voltage shall be PVC insulated to BS 6231,
Type B in phase colours with a minimum size of 1.5mm². As
an alternative to coloured cables, labeled black cables may
be used for Phase connection with colour coded ferrules.
(ii)
Extra low voltage wiring shall be carried out in flexible PVC
insulated cable to BS EN 50525 with a minimum size of
1mm².
(iii)
The colour coding shall be as follow:

Phase connections – Brown, Black and Grey;

Neutral connections - blue;

Earth connections - green/yellow; and

DC Circuits - grey with red and black ferrules to
denote polarity.
(iv)
Wiring shall be carried on the front surface of the mounting
plate either neatly strapped in plastic cable trunking of the
ventilated type with clip-on covers and purpose made
connector pieces and accessories, or strapped in looms with
straps permitting easy access to the looms and clipped to the
mounting plate.
(v)
All control wiring shall be identified with numbered ferrules.
All wires associated with tripping circuits shall have red
ferrules marked "Trip". The numbers shall be shown on the
schematic wiring diagram.
(vi)
Terminals shall be suitably rated, fully fitted and numbered.
They shall be normally mounted for top entry and front
access. They shall be suitably sized to cater for long runs of
externally mounted cable whose voltage drops necessitate a
larger size than standard for the connected load.
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e.
f.
Operation
(i)
The Synchronising Control Panel shall be designed for
automatic operation on mains failure.
(ii)
When the mains supply is normal, the load is fed through the
mains supply switch of the automatic transfer pair.
(iii)
The automatic control circuitry shall be arranged to serve a
fault or failure of any phase of the mains supply voltage, and
on receipt of such a signal the mains supply switch shall deenergise, open and the engine starting circuit shall be
initiated.
(iv)
The mains supply voltage sensing unit shall not only detect a
complete mains fault or failure but shall also sense a voltage
drop of up to 20% or more in any phase of the normal mains
voltage.
(v)
When the voltage and frequency (engine speed) of the
generating set at up to normal values, the standby supply
switch (mechanically and electrically interlocked with the
mains supply switch) closes, thus providing electricity supply
to the essential services.
(vi)
The duration of the entire starting sequence shall be within
ten seconds from the moment of mains failure to standby on
load. The Contractor shall state clearly in the Tender the
period in seconds that would elapse for the generating set to
complete the starting sequence from the moment of mains
failure.
(vii)
When the mains supply returns to normal, the load shall be
transferred automatically to the mains supply.
The
generating set shall shut down after a preset time delay, and
the equipment shall reset for the next duty operation.
(viii)
The starting battery is maintained in a fully charged state
when the set is idle by a mains operated battery charger.
Beacon Light
An orange beacon light shall be provided to indicate that the standby
generator is running. It shall be located outside the standby
generator room.
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14.2.17
Generator Set Acoustic Enclosure
a.
General
(i)
Acoustically treated weatherproof enclosure to achieve
75dBA measured at 1-meter all round the enclosure (under
free field condition) shall be provided for the diesel generator
set. The enclosure shall be suitable to be placed in an
outdoor environment.
(ii)
The enclosure shall be pre-assembled as a complete unit
and includes the following:

Diesel generator set comprising engine, alternator
and radiator on a common baseframe

1000 litre day fuel tank,

Generator set automatic mains failure panel,

Battery bank and automatic charger unit,

Sufficient lighting fixtures to provide illumination for
maintenance purposes (applicable for big generator
set enclosures),

The circuit breaker panel and control panel shall be
set mounted on the base frame instead of set
mounted to minimize the vibration of the cable
termination when in operation.
(iii)
The performance of the enclosure shall be designed and
constructed to ensure that the specific acoustic criteria are
met without affecting or derating the diesel generator set
rating specified.
(iv)
The design of the enclosure must provide sufficient space for
maintenance and operating purposes, maintenance aspects
on the generator set shall not be compromised.
(v)
Lightings with switches shall be provided within the enclosure
for 4 hours duration, powered by a dedicated DC supply.
(vi)
External pipe connections and openings must be provided at
the enclosure such as:

Lubricating oil drain point,
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b.
c.

Engine breather outlet,

External fuel pipelines connection – for automatic
fuel filling,

Cable entry to the generator set termination box.
Enclosure Baseframe
(i)
The generator set acoustic enclosure can be housed as an
integral skid mounted and completely portable unit that would
only required a single crane to lift the complete generator set
without any re-assembly work on-site.
(ii)
For special applications and site constraint, etc, the
generator set may be installed on a concrete base with the
acoustic enclosure mounted over the generator set and
sealed to the concrete.
(iii)
The complete generator set baseframe shall be hot-dip
galvanized.
Enclosure Body
(i)
The outer skin of the enclosure shall be of stainless steel
sheet (316) of not less than 2.5mm thick.
(ii)
The inner skin of the enclosure, including all doors, shall be
lagged with approved type of non-combustible acoustic
material. The construction of the acoustic insulation shall
comply with the sound level stipulated above.
(iii)
The enclosure shall come complete with stiffeners to ensure
that the external wall, doors and ceiling are all strongly
assembled as one unit and will not warp or break during the
transportation and hoisting of the enclosure.
(iv)
The enclosure shall have minimum four lifting points for
transportation and hoisting.
(v)
Catladder with full length handhold to the top of the
enclosure roof shall be provided.
(vi)
Provision shall be made for proper accessibility for
maintenance.
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d.
e.
f.
Enclosure Doors
(i)
The enclosure shall come with full height doors on each side
of the enclosure to give personnel entry. Rain shade shall be
provided for each door. The location of the doors shall be
designed so as to facilitate the easy access to the genset
and its installed components for maintenance staff for the
maintenance of the generator set.
(ii)
Heavy duty hinged doors complete with stainless steel
lockable lock-sets shall be provided to each door. Additional
latches or panic hinges shall be provided on the inside of the
lock-sets to release the door mechanism from the inside of
the enclosure to ensure that personnel working within the
enclosure will never get locked in when the doors suddenly
slam shut.
Enclosure Air Flow
(i)
Fresh air inlet and radiator exhaust outlet for the enclosed
generator set must be carefully designed to ensure proper
ventilation during the operation of the generator set. The
fresh air inlet air flows into the enclosure, besides providing
cooling air to the engine radiator unit, also takes care of the
heat dissipation for the diesel generator set and it’s
associated equipment.
(ii)
The airflow velocity at the inlet and outlet of the enclosure
must not be excessive and shall be below the allowed
velocity needed to achieve the acoustic performance
specified.
(iii)
The manufacturer must submit airflow calculation to ensure
that the overall airflow pressure / static within the acoustic
enclosure from the fresh air inlet position to the radiator hot
air outlet position is within the engine radiator fan allowable
external static pressure. External fan shall be provided for
the acoustic enclosure to ensure proper operation of the
generator set if the engine fan is not capable of providing the
required airflow and static pressure. However, the nett kW
rating of the generator set shall not be affected or reduced,
manufacturer should size the fan within the generator set
allowable losses.
Sound Treatment to the Enclosure
(i)
Sound attenuation must be provided at the fresh air inlet and
radiator exhaust outlet. The method of attenuation shall be
approved by the Engineer. Sound attenuation section must
be constructed using similar material as that used for the
construction of the enclosure and acoustic insulation.
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(ii)
g.
h.
If acoustic splitters are used for sound attenuation, the
splitters shall be aerodynamically shaped, having a bull nose
at the inlet and followed by a parallel-sided section of varying
length and terminated by an optimised tapered section.
Engine Exhaust System
(i)
Residential exhaust silencer must be installed and connected
to the engine through steel flexible and flanged pipe work.
For acoustic enclosures requiring higher sound attenuation,
an additional / secondary silencer must be installed.
(ii)
Exhaust pipe and flexible pipe within the enclosure shall be
lagged with a heat insulating material and clad externally with
aluminum sheet.
(iii)
Exhaust silencer, exhaust pipes and fittings shall be of
stainless steel SS 316 materials.
Fuel System
(i)
Fuel day tank must be constructed as per the tender
specification. Fuel tank installed within the enclosure shall be
provided with a means of containing any leaks from the tank
and prevent any leakage of diesel out of the enclosure into
the open.
(ii)
Fuel pipeline shall be installed within the fuel tank and the
engine; flexible fuel pipeline must be used between the
engine and the fuel pipeline.
(iii)
Proper fuel filling point and fuel level gauge must be provided
and be easily accessible and visible. External fuel pipe
connection points must be provided if external fuel transfer
system is required.
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14.3
Execution
14.3.1
Cabling
a.
Mains Cables and Connections
(i)
The Contractor shall provide and install all mains supply
cables as shown on the specification and drawings. The
cables shall be Fire-Resistant (FR) Cable unless of otherwise
specified.
All circuits shall be provided with separate
continuity conductors sized to comply with SS 638.
(ii)
The cables shall be properly fixed on perforated metal cable
ladder with PVC covered metal saddles or plastic saddles at
450mm intervals. Where the run of cables and ladder is on
the ground, it shall be encased in metal trunking.
(iii)
All terminations, fixings, tools and accessories shall be of the
same manufacturer as the cable installed. Terminations
shall comply with BS EN 60702-2, IEC 60702-2 with
dimensions rationalised to suit cables complying with BS
6207-3.
(iv)
Terminations of the PVC sheathed cables shall be protected
by the correct size of plastic gland shroud. Any exposed
metal sheath remaining after the installation of the installation
of the cable gland shall be wrapped with PVC tape, as
supplied by the cable manufacturer, before fitting the gland
shroud.
(v)
Suitable anti-vibration loops on bends shall be formed in the
cables immediately prior to termination in accordance with
the cable manufacturer's recommendations. Any loop shall
be formed such that the two sections of cable do not touch at
the point of crossover.
(vi)
At all terminations, great care shall be taken to maintain
earth continuity. All glands and locknuts shall be effectively
fitted and tightened to the manufacturer's recommendations.
(vii)
The insulation resistance of a terminated cable shall be
greater than 100 Megohms when measured with a 500 volts
or 1000 volts insulation tester immediately after sealing. This
test shall be repeated not less than twenty (24) hours later.
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b.
c.
Small Wiring
(i)
All small wiring shall be PVC insulated and PVC sheathed
single core copper cables, rated at 600/1000 volts and
complying to BS EN 50525. All conductors shall be at least
2.5sq.mm in cross sectional area.
(ii)
Cables shall be protected throughout their length by a
continuous enclosure of conduit or trunking except where
cables are installed within the enclosure of electrical
equipment.
(iii)
All circuits shall be provided with separate earth continuity
conductors sized to comply with SS 638.
Operation
(i)
Complete or partial failure of Utility’s electricity supply
(including voltage drop in any phase to 80% of Utility’s
declared value) at the transformer feeder shall be detected
by the sensing relays of the standby generators. Thereupon
the 'mains' contacts of the associated automatic transfer
switches (ATSs) shall be opened and the engine and the
auxiliaries (i.e. radiators fans, etc.) shall be started up after a
short time delay. As soon as speed, frequency and voltage
of the standby generator reach the operating values, the
'standby' contacts of the ATSs shall be closed and
arrangements shall be made to transfer the loads to the
standby generators concerned in 3 steps of loads not
exceeding approximately 60%, 20% and 20% of the capacity
of the standby generators sets. The loads to be designated
for each of the steps shall be subject to the Engineer's
approval. The costs of providing changeover contactors,
time delay relay, motorised ACB/MCCB's, wiring, etc. as
required to achieve this load transfer shall be deemed to
have been included in the Contract Sum. The transfer of the
entire loads shall be effected within 10 seconds after the
closing of the ‘standby' contacts of the ATS.
Upon
restoration of the mains supply, the process shall be
reversed i.e. the 'standby' contacts of the ATSs shall be
opened to be followed by closure of the 'mains' contacts of
the ATSs.
(ii)
Time delay circuits shall be incorporated in the control circuit
of the standby generators set so that changeover to mains
after mains supply has been resumed shall only be effected
after the engine has run for a minimum period of 15 minutes
after start up and 15 minutes after mains resumption to
ensure that the engine is not repeatedly started and stopped
in the event of a series of supply interruptions.
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d.
e.
Automatic Operation
(i)
On operation of the voltage relay at the upstream of the
‘Normal' breaker of the ATS in the designated LV
switchboard during failure of the mains supply, a signal shall
initiate the start-up system of the engine.
A time delay,
adjustable between 0 to 5 seconds, shall be incorporated in
the system to prevent automatic starting in the event of
momentary voltage interruptions to the mains supply.
(ii)
If the failure persists at the expiry of the time delay period the
prime mover start sequence shall begin.
(iii)
Within 15 seconds of the start sequence commencing, the
generating set shall be established at its running speed and
full load transfer shall take place automatically.
(iv)
Should the prime mover fail to start after a period of 15
seconds, the sequence shall be interrupted for a period of 5
seconds and a further two attempts to start of 5 seconds
duration shall then be made. If it again fails to start, the
starting sequence shall be locked out, an audible and visual
alarm given and it shall remain in this locked out condition
until manually reset.
(v)
Restoration of the mains supply during the starting period
shall not interrupt the starting sequence but shall prevent
operation of the load transfer. Subsequent failure of the
mains supply while the generating set is running shall, after
expiration of the 0.5 to 1.0 seconds time delay, cause the
load transfer to take place.
(vi)
On full restoration of normal supply, load transfer and
shutting down of the generating set shall be either by manual
or automatic operation selectable by a selector switch on the
control panel. Upon activation of this command, load
transfer shall take place immediately. The generating sets
shall run unloaded for a short cool-down period of 0 to 15
minutes adjustable and then shut down.
Manual Operation
(i)
The control panel shall also be equipped with an
"Auto/Manual" rotary control switch. The system shall
operate as described above in "Auto" selection and shall hold
the existing status of the system until manual controls are
effected.
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f.
(ii)
The generating set shall be able to start manually, by control
switches located on the control panel. Once started and
running normally, the generator can be manually connected
to the desired essential loads.
(iii)
During the whole of the manual starting sequence, all the
loads shall not be transferred to the generator as long as the
mains power remains available. However, upon actuation of
a "Manual Load Transfer" push button, a signal shall be
initiated to open the "Normal" circuit breaker and close the
"Standby" circuit breaker to enable load transfer as per in the
automatic operation.
By re-setting the "Manual Load
Transfer" push button, the load shall be transferred back to
the mains supply.
Synchronising Facilities
Manual synchronizing facilities, with synchronizing check features,
are required for the circuit breakers controlling the generators, stepup transformers and bus-sections. Automatic synchronishing facilities
shall be additionally supplied on the generators.
Where the terms “running” and “incoming” are used, the term
“incoming” shall apply to the circuit which is to be synchronized with
the power system and “running” refers to the power system.
The hinged synchronizing panel or trolley located in the power plant
control room shall be equipped as follows:1 – ‘Incoming’ voltmeter
1 – ‘Running’ voltmeter
1 – Synchroscope
1 – Auto/manual synchronishing selector switch
1 – 3 position manual synchronishing selector switch with “OFF”,
“SYNCH CHECK”, “SYNCH CHECK OVERRIDE” positions
1 – ‘Synch Check in Service’ white lamp
1 – ‘Synch Check Override’ amber lamp
2 – Lamps bright at synchronism
1 – Phase Reversing VT
1 – Automatic synchronishing relay
1 – Synchronising check relay
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1 – ‘DEAD LINE” undervoltage check relay
1 – ‘DEAD BUS” undervoltage check relay
If a hinged panel is used, instruments shall be sufficiently large to
permit easy viewing from each section of the power plant control
panel. If a trolley is used, it shall have large diameter rubber tyred
wheels and shall be complete with a plug and lead with facilities for
storage of the trailing cable when it is not in use.
Interlocking shall be provided such that the relevant circuit-breaker
cannot be closed manually unless the relevant circuit has been
selected for synchronishing.
Synchronising check relays shall check the phase and magnitude of
the voltage difference at synchronising with contacts connected to
prevent inadvertent manual synchronishing outside acceptable limits.
Synchronising check circuits shall be arranged such that the relevant
circuit-breaker will not close if the circuit breaker control switch is put
into the “CLOSE” position, when the measured parameters are
outside of the prescribed limits, and held in that position.
Means shall be provided at the synchronizing panel to override the
check circuits when switching dead equipment or lines, together with
warning lamp indication that the relays are out of circuit. This facility
shall be padlock such that override can only be selected after the
padlock has been removed. Deadline, or deadbus, check features
shall be included to prevent the use of override facilities for closing a
circuit-breaker which would result in the connecting together of live
circuits and/or busbars.
14.3.2
Automatic Features
The generating set shall be provided with the following automatic protective
features complete with indicating lamps:
a.
Shutdown
(i)
The generating set shall shutdown under any of the below
conditions:
if the coolant temperature exceeds a safe figure;

if the speed exceeds a safe figure;

if the lubricating oil pressure falls below a safe figure;
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(ii)
b.

if there is an overload on any or all of the phases;

if there is an under or over voltage; and

if there is an operation of protective relay.
Failure warning lights and audible alarm sounder
connections for remote indications shall be incorporated to
indicate that the generating set has shutdown due to any of
the above mentioned. The generating set main circuit
breaker shall be opened under any of the above abnormal
conditions and interlocked to prevent the breaker from being
close unless the engine is running and all conditions restored
to normal.
Mains Voltage Monitoring
The mains voltage shall be monitored on all three (3) phases, failure
or low voltage (below 10% of the rated voltage) on all/or anyone
phase will initiate starting of the generating set.
c.
Starting Delay
An adjustable starting delay over 5 seconds shall be provided to
prevent the diesel engine starting up unnecessarily during transient
voltage fluctuation.
d.
False Start
If the engine fails to start up after three numbers of attempted start,
the generating set which is incorporated with an automatic system
shall prevent any further starting and at the same time sets up an
audible and visual alarm indicating that the plant has failed to start.
e.
Repeat Starting
A triple repetition of the starting process shall be incorporated in the
system.
f.
Taking Over the Load
The load shall only transferred to the generating set when the
alternator has reached its rated voltage and shall be approximately
10 seconds after starting of engine.
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g.
Alternator Voltage Monitoring
The alternator voltage shall be continuously monitored on three
phases. If the voltage drops below the 10% value, the alternator
breaker or contactor shall be opened and an alternator fault indicated
both visually and audibly. Automatic re-energisation of the alternator
will be blocked.
h.
Delayed Main/Resumption
An adjustable time delay (0 to 30 minutes) to prevent the set from
shutting down in the event of a momentary mains return must be
provided in the system.
i.
Slowing Down
After reconnection of the load to the main supply, the unloaded
generating set shall continue to run for about 5 minutes before
stopping.
j.
Emergency Shutdown
An emergency push button to disconnect the entire standby
generating plant, shutdown the generating set and block the
automatic system shall be incorporated in the plant.
k.
Operation Selector Switch
A selector switch shall be provided for the following modes of
operation:(i)
Manual starting/stopping of the engine - intended for
commissioning and maintenance of the plant.
(ii)
Automatic operation
(iii)
No load test - to test the functionality of the standby
generating plant without connection to the load. The test
duration shall be terminated automatically by a timer and
adjustable over 15 minutes. Any failure or abnormalities that
would arise from this test would bring on the alarm.
(iv)
Load test whereby a failure is simulated and the complete
process of load take-over by the standby generating plant is
tested.
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14.3.3
14.3.4
Generator Plant Room
a.
The Contractor shall install a framed Single Line Diagram of the main
circuit, change-over and supply scheme, and control circuit diagram
in the generator plant room.
b.
A first aid chart shall also be provided and displayed.
b.
The Contractor shall provide a 5mm thick x 750mm wide rubber mat,
extending the length of the control panel, placed in front of the control
panel.
c.
A key box cabinet to accommodate keys and generator plant 200
page log book).
d.
Wall mounted collapsible Table.
e.
Danger signage on Generator, HV equipment generator plant room
doors etc.
Painting
In addition to painting the control panel as previously specified the Contractor
shall paint the standby generator set bed plate in a similar manner as
specified for the control panel and shall touch up any paintwork of the diesel
engine, alternator, control panel, etc. damaged during site installation.
14.3.5
Acoustic Treatment
A suitable sound proofing techniques shall be applied to the generator room
such that the noise level of the generator room measured at 1m from the
circumference outside the generator room shall not exceed 70 dBA.
14.3.6
Interfacing with Building Management System (BMS)/Power Monitoring and
Control (PMCS)
a.
The BMS, to be provided by others, shall monitor and log the
conditions of the standby generating plant as indicated in Table
below contained in the Specification. All status and control wirings to
be linked to the BMS shall be brought to a marshalling cubicle from
which the information will be picked up by the field equipment of the
BAS (Building Automation System). All status and control interface
shall be provided in the form of dry contacts, and in pairs of N.O. and
N.C. contacts.
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Table : Monitoring of Standby Generating Plant
Device/Alarm
Interfacing with
Control panel
The Building
Automation
System
Alarm/Status
Alarm/Status
Main supply status
X
X
Generator breaker status
X
X
Generator breaker trip on fault
X
X
Generator running
X
X
Engine overcrank lockout
X
Common alarm
Engine overspeed shutdown
X
Common alarm
Engine fail to start
X
Common alarm
Low fuel level
X
Common alarm
Low lubricating oil pressure
X
Common alarm
High coolant temperature
X
Common alarm
Battery system fail
X
X
Battery discharging
X
Common alarm
X denotes individual function/signal required.
b.
14.3.7
14.3.8
The marshalling cubicle shall be installed inside the
Room and shall be of an approved design.
Generator
Earthing
a.
An earthing terminal shall be provided in the Generator Room for the
earthing of the standby generating plant.
b.
The generator frame, generator neutral, fuel service tank, generator
switchboard, cable trays/ladders, etc. shall be individually connected
to the earth terminal provided in the Generator Room. The size of
the protective conductors shall not be less than 3mm x 25 mm
copper.
Testing
a.
Test in Works
(i)
Acceptance tests shall be carried out at the works of
manufacturer to establish that the generating set complies
with the Specifications and is entirely suitable for its intended
purpose.
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(ii)
All tests shall be made in a manner prescribed in the relevant
British Standard Specification.
For Engine
1.
2.
Test measurements of the following:

cooling water temperature;

lubricating oil temperature and pressure;

exhaust gas temperature;

fuel and lubricating oil consumption;

protection circuits settings (e.g. over-speed
trip, lubricating oil pressure trip, cooling
water temperature trip); and

brake horse power.
Functional checks to demonstrate:

the ability of all malfunction and protection
and warning devices to respond correctly to
conditions in which they should operate;

the dynamic and steady state characteristics
of the governing system; and

the ability of the starting system to perform in
accordance with the Contract.
For Alternator
1.
Test measurements of:

temperature rise of alternator and exciter
windings;

coil resistances of alternator and exciter
windings; and
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
2.
insulation resistance of alternator and exciter
windings.
Functional checks to demonstrate:

withstand flash test for one (1) minute;

voltage regulation with automatic voltage
regulator and manual control (if fitted); and

a load test of sufficient duration for the
alternator to reach its final steady operating
temperature followed by one (1) hour at
110% load.
The load test shall be conducted complying to the
Specification. The Contractor shall be responsible
for providing the artificial load bank.
The manufacturer shall provide a test report
embodying the results of all tests carried out, after
completion of the tests. The test report shall contain:

a description and identification of the
equipment tested including fabrication block
and production numbers;

the name, address and contract or order
number of the Contractor ordering the
equipment;

date, place and time of test;

the testing party and the signature of the
testing Engineer;

the properties tested and the source of the
parameters for such properties, that is British
Standards; and

the results of the test and any deviations
from the Specifications.
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No item of equipment subject to inspection and test
shall be despatched from the works of the
manufacture until the Engineer has received and
approved in writing the results of the tests.
Acceptance of test reports and approval of tests by
the Engineer of any equipment shall not relieve the
Contractor from an obligation to supply the complete
equipment in accordance with the Contract
Specifications and suitable for the purpose intended.
b.
Load Tests
(i)
The generating set shall subject to a step-load of 100% or
better with voltage dip not more than 20% in cold start
condition. The load shall be a combine of resistive and
reactive load bank.
(ii)
The generating set shall subject to the following steady-stale
load tests at the manufacturer's premises. The voltage and
frequency responses shall be recorded by a high-speed
recordor to the acceptance:
Load
Duration
25% Full Load
10 mins
50% Full Load
10 mins
75% Full Load
10 mins
100% Full Load
1 Hours
110% Full Load
30 mins
During the load test the following items shall be recorded at
15 minutes interval:

cooling water temperature;

engine oil pressure and temperature;

exhaust gas temperature;

fuel and lubricating oil consumption;
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(iii)

speed (frequency);

voltage;

current;

load in kW; and

measurement harmonic spectrum of output voltage.
The generating set shall subject to the following impact load
tests. The voltage and frequency responses shall be
recorded by a high-speed record to the Engineer's
acceptance:

0 to 25% Full Load Step;

0 to 50% Full Load Step;

0 to 60% Full Load Step;

0 to 75% Full Load Step; and

100% to 0% Full Load Step.
The voltage and frequency dip/rise and recovery time shall
meet the relevant BS standards referred in this specification.
14.3.9
Tests on Site
a.
The Contractor shall arrange with the Engineer for all tests at least
seven (7) working days in advance. He shall supply all necessary
instruments, apparatus, consumable stores, fuel, connections, skilled
and unskilled labour and services with proper, reasonable and safe
facilities required for the tests. Any costs which may be involved in
the tests shall be included in the lump sum tender by the Contractor.
The Contractor shall satisfy the Engineer that the instruments and
equipment to be used for any tests are adequate with regard to
accuracy and calibration for the tests to be undertaken.
b.
A complete written record shall be made by the Contractor of all
inspections and tests. These records shall be made at the time of
the tests and shall be countersigned by the Engineer as a true
record. A copy of each record sheet shall be included with the
operation and maintenance manual.
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c.
Inspection or approval of tests and acceptance of test certificates by
the Engineer of any equipment, works or installation shall not relieve
the Contractor from the obligation to supply the complete equipment
and complete work and installations in accordance with the Contract
Specifications and suitable for the purpose intended.
d.
Three (3) copies of certificates of test shall be submitted to the
Engineer within fourteen (14) days of completion of tests.
e.
Certificates of test shall contain or have attached to them the
following information:
f.
14.3.10
(i)
the name of Contract and Contract No. as designated by the
Engineer;
(ii)
a description of equipment, system or installation tested
including any fabrication, block or production numbers;
(iii)
the name and address of the Contractor;
(iv)
date and time of the test;
(v)
environmental conditions;
(vi)
the testing party and the signature of the Contractor's testing
Engineer;
(vii)
the results of the test and any deviations from Specifications
and Drawings; and
(viii)
signature and stamp of the Contractor's Professional
Engineer.
Any faults or defects revealed by the inspection or testing shall be
made good and re-testing shall be made, all at the expense of the
Contractor.
Load Test
a.
Test Criteria
(i)
Steady-state voltage +2.5% variation.
(ii)
Steady-state frequency +1% variation.
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b.
c.
(iii)
The diesel engine must operate normally without leakage of
fuel, lubricating oil, water and exhaust gas.
(iv)
The diesel engine must not stall.
(v)
The data obtained during the test must be consistent with the
data obtained from previous tests of the same generator.
Test Procedure
(i)
Connect the test resistor load to generator output.
(ii)
Start the generator without load and let it run free for an hour
for warming up.
(iii)
Apply 100% load and take readings as tabulated every 20
minutes for 2 hours.
(iv)
Increase the load to 110% and two (2) further sets of
readings one at 10 minutes and the other at 30 minutes later.
(v)
Apply the dynamic load test by quickly varying the load from
0% to 100% and back to 0% in step of 25% load variation.
Take readings for each load condition
(vi)
Put the generator in full load and then cut load off and then
full load again for another three (3) sets of readings.
Precautions
(i)
The test resistor load area must be cordoned off.
(ii)
One electrician must be standing by to monitor the operation
and record measurement data at equal time interval.
(iii)
Fire extinguisher must be made available before starting the
generator.
(iv)
Warning sign must be displayed at test resistor load.
(v)
All electronic components must be isolated and all capacitors
must be short-circuited before performing the insulation tests.
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14.3.11
Drawings
a.
b.
14.3.12
Layout of Plant and Equipment
(i)
The Contractor shall submit the general layout of the
generator set, control panel, fuel tanks, pipe work, exhaust
outlets, etc. which is to be consistent with the size of the
generator plant room.
(ii)
Unless otherwise indicated, any plinths and trenches
necessary for the installation of the generator shall be
provided by the Contractor at his own cost.
(iii)
Layout, construction and installation drawing will be drawn on
A1 sheets and details may be produced on A4 sheets.
Working Shop Drawing and Schedules
(i)
The Contractor shall, before the relevant works proceed,
prepare and submit for approval by the Engineer all working
drawings based on the Contract Drawings. They shall take
into account any modifications, either to the building or the
installation which may have taken place, incorporating details
of the actual items of plant and equipment to be installed.
(ii)
The Contractor shall prepare all necessary schedules of
equipment and necessary wiring diagrams, including internal
diagrams for items of electrical equipment and diagrams
showing the inter-connection between different items.
(iii)
The single-line diagram of the main circuit showing the
change over arrangement shall be duly endorsed by the
Contractor's Professional Engineer.
(iv)
The Contractor shall, prior to commencing manufacture,
submit to the Engineer for technical appraisal,
manufacturer's shop drawings of the duct and pipe work to
be supplied and erected under the terms of the Contract.
Drawings shall relate the location of ducts and pipes with the
supporting and adjacent building structure.
Manuals
a.
Operation and Maintenance Instruction Manuals
(i)
The Contractor shall provide the Engineer with copies of the
Operation and Maintenance Instruction Manual for the
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b.

record drawings of the installation;

general description of systems;

setting up and operating instructions
equipment and systems installed;

control sequences for systems installed;

the scheduled details of all equipment settings and
actual values maintained in controlled variables
during commissioning;

frequency and details of routine maintenance
requirements for all plant and equipment, shown on
a set of schedules produced for this purpose; and

manufacturer's literature, including detailed drawings
and electrical circuit details, printed operating and
maintenance instructions, for all specific items of
equipment and plant supplied under this Contract.
for
all
(ii)
The manuals shall be encased in A4 size plastic covered
loose leaf ring binders, with hard covers. Drawings larger
than A4 shall be folded and accommodated in the binder so
that they may be unfolded without being in any way detached
from the rings.
(iii)
Attention is drawn to the fact that the Works will not be
accepted as complete and that final payment will not be
made for the Works until the manuals have been accepted
by the Engineer as being satisfactory.
(iv)
The Contractor shall provide training to the Engineer and the
Board's maintenance staff in the running of the plant and
system. The location and function of all items listed on the
record schedules and the procedures for starting up, shutting
down, isolating sections, etc. shall be comprehensively
explained and demonstrated to the Engineer's satisfaction.
Fuel
Upon completion of works, the Contractor shall provide sufficient
diesel fuel to fill up fully the daily service fuel tank and the
underground storage tank. The engine shall operate satisfactorily on
light diesel fuel oil to BS 2869 Class A2.
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c.
14.3.13
Spare Parts
(i)
The Contractor shall provide, on completion, two copies of
the Spare Parts Manual for the generating set. Full details of
all engine parts and assembly shall be provided in the
manuals.
(ii)
The Contractor shall guarantee that spares will be obtainable
locally for a minimum period of over ten (10) years from the
date of completion.
(iii)
The Contractor shall supply the following spares and tools for
each generating set installed:

one (1) fan belt, one (1) oil filter element with seals
and one (1) fuel filter element with seals; and

one set of maintenance tools and gauges (as
recommended by the generator manufacture)
contained - suitable steel box with lids fitted with
padlock.
Operational Training on Site
Training in the operation and maintenance of the standby generator set for
Technical personnel from the Employer shall be carried out on site after
testing and commissioning. For Tender purposes, the Contractor shall
include allowances in his Tender for a one (1) week training period.
14.3.14
Specialist Maintenance During Defect Liability Period
a.
The Tender shall include for any normal service and maintenance
required during the Defect Liability period on all plant and equipment
supplied under the Contract.
b.
In addition, the Contractor shall perform the following test run and
maintenance routine monthly within the Defect Liability Period:
(i)
initiate automatic starting and stopping of the generating set
through simulated mains failure and restoration of normal
supply;
(ii)
test run the generating set for a minimum period of half an
hour;
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(iii)
before starting, check lubricating oil, level cooling, water
level, fuel level, battery electrolyte level, and refill if
necessary;
(iv)
during running, check and record voltage, current, frequency,
power factor, hours, counter, lubricating oil temperature and
pressure, engine speed and cooling water temperature;
(v)
check for leakage and loose connections in fuel, lubricating
oil and water piping and electrical wiring;
(vi)
check and record battery voltage and charger current; and
(vii)
clean battery terminals and check tightness of connection.
c.
Each of the above test run routine maintenance shall be carried out
in the presence of the Employer's representative.
d.
The Contractor shall supply all necessary lubricating oil, battery
water, coolant, grease, etc. for topping up during the fortnightly test
run and routine maintenance.
e.
Should any parts, equipment or material become defective or faulty,
the Contractor shall replace and rectify such defects and faults at no
cost to the Employer. All efforts shall be made to avoid putting the
system out of service in the event of repair.
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