This section covers manufacture, installation and commissioning of new diesel engine generators to be installed in the Kambia/Rokupr Townships . Unit capacity of the diesel engine generating (DEG) will be 2 x 500 kW (totaling 1MW) with model number: MTU 12V2000G65 Genset and the operation mode will be base load operation.
Fuel Oil
The diesel engine shall be capable of continuous operation with diesel oil.
Lubricating Oil
Lubricating oil shall be used for the DEG units. Type of lubricating oil is to be determined by engine manufacturer.
Cooling water shall be used for the closed cooling system of the DEG units. The cooling method of engine to be determined by the manufacturer.
2. DIESEL ENGINE GENERATING FACILITY
Two (2) sets of diesel engine and their auxiliary equipment with specifications described hereunder shall be installed under the Project.
The diesel engine shall be of the single action, four (4) strokes, turbo-charged, water cooled, inter-cooled, compression ignition type, multi-cylinder type diesel engine.
The diesel engine shall be operated from the engine local panel located beside the diesel engine.
The Engine shall be operated at a rated normal speed1500 rpm. The main critical speed of the engine shall be above the rated speed of the engine and must be as far as possible from the normal speed. The engine and the connected apparatus shall be mechanically designed for an over speed of 10% and equipped with an over speed protection device in accordance with ISO standards. The dangerous harmonics shall not interfere with the tolerated values of the normal speed operated within ±5% of rated speed.
The diesel engine shall be so balanced as to eliminate excessive vibration that should be within the permissible level in accordance with ISO standards.
The voltage and frequency transient variations and recovery time upon block load application or removal shall be in accordance with Class G2 of ISO standards.
The engine shall be designed for an operational life span of 25 years. (40 OC ambient temperatures, 80% relative humidity and atmospheric pressure at sea level).
A certificate or any related document to this effect shall be submitted to the Client and the Consultant. BMEP (Brake Mean Effective Pressure) shall not exceed 25 kg/cm2 at a minimum rated output of 500 kW under the site environmental conditions specified above.
The Contractor/engine manufacturer shall determine the overall length and height of the engine and generator set based on the dimensions of the powerhouse to be specified.
Major specifications of diesel engine are as follows;
(1) Operation : Continuous (base load in excess of 7800 hr per year)
(2) Rated output : 500kW
(3) Revolution speed : Not more than 1500 rpm
(4) Engine type : V, turbo charged, water Cooled
(5) Cooling : Radiator cooling
(6) Fuel oil : Diesel oil
(7) Engine type : MTU 12V2000G65
The output of each diesel engine generating unit shall not be less than 500 kW measured at the generator terminal when the unit is operating under the ambient temperature of 40 degree C, relative humidity 80% and atmospheric pressure at sea level.
The engine shall be capable of producing the maximum continuous output under the above mentioned combination of ambient temperature, pressure and humidity. In addition, the unit shall be capable to operate on ten per cent (10%) over load for a period of one (1) hour in every twelve (12) hours operation.
The fuel oil consumption at ISO condition of the diesel generating units at the rated output shall not exceed 210g/kWh at the generator terminal. This will be obtained by combustion of the diesel oil having 42.7 MJ of gross calorific value, provided the generator is to be continuously operated for one (1) hour at 500 kW, and no tolerance on the stated maximum fuel oil consumption will be allowed.
The governor speed of the engine shall be of an electronic type and be adjustable in a range of plus or minus five per cent (5%) of the rated speed at no load and full load condition.
The speed regulation shall be made as follows:
(1) A sudden 100% decrease of load
(a) Transient speed difference: Not more than 15%
(b) Recovery time: Not more than 15 sec.
(2) A sudden Increase in load (25% load increase of rated load from no load)
(a) Transient speed difference: Not more than 13%
(b) Recovery time: Not more than 13 sec.
The speed droop shall be adjustable during operation from zero (0) to six percent (6%).
The Engine shall be provided with turbo-charged facilities of exhaust gas driven type turbocharger(s).
2.1.6 Engine Driven Pumps
Engine shall be equipped with one (1) lubricating pump driven directly by the engine shaft having sufficient capacity .
2.1.7 Engine Installation
The engine and generator shall be installed on the common bed with vibration damper.
2.1. 8 Engine Protective System
The following accessories shall be provided to safeguard the engine set from being damaged by dangerous operation thereof:
Any other device(s) as the Contractor / engine manufacturer considers essential for the safe and sound operation of the engine shall be provided.
(1) Suitable over-speed trip device operated at an adequate speed not more than fifteen per cent (15%) of the rated speed.
(2) An alarm and tripping devices for the engine in the event of excessive low cooling water and lubricating oil pressure.
(3) Voltage rise and over current of generator frequency/voltage variations
(4) Sufficient number of crankcase relief valves to match the free area to crankcase volume.
2.2.1Diesel oil Transfer Pump
One (1) Diesel oil transfer pump shall be provided for each engine for the transfer of Diesel oil from the storage tank to the Diesel oil service tank.
One (1) duplex bucket strainer shall be provided on pump suction piping for the purpose of pump protection.
Pump shall have solenoid valve to stop the gravity oil flow when heavy fuel oil transfer pump is not on duty.
Pump type shall be of out-door, AC motor driven, gear type and the capacity shall be not less than 3.0 m3/hr at 3kg/cm2.
The pump shall be automatically operated by the oil level switch mounted on the diesel oil service tank.
2.2.2 Fuel Oil Flow Meter
One (1) fuel oil flow meter shall be provided on the pipelines to each diesel engine. the flow meter shall be of a direct reading integrated type with suitable capacity for the maximum fuel oil flow, and with an accuracy class of within 1.0 % of the full scale.
2.2.3 Diesel Fuel Oil Filter
One (1) duplex basket type filter shall be provided for the filtration of fuel oil before the Diesel storage tank.
2.2.4 Diesel Fuel Oil Primary Filter
One (1) duplex basket type filter shall be provided for the filtration of fuel oil before the flow meter for each diesel engine.
2.2.5Fuel Oil Secondary Filter
Secondary oil shall be provided on the engine inlet for the engine fuel oil system. The fuel oil Secondary filter shall be of a single basket and a cartridge type.
The lubricating oil system shall be provided and installed for the diesel engine generator set and shall consist of filters, pumps, coolers, valves, temperature control valves, etc.
2.3.2 Lubricating Oil Filter
lubricating oil filter having the most appropriate filter ability shall be equipped for the system at the engine inlet.
The cooling water system shall be provided and installed for the diesel engine generating system. City water which is used for cooling water shall be supplied from existing city water supply.
The radiator shall be provided of radiating the engine heat generation sufficiently and to be designed with aconsideration of ten percent (10%) fouling margin.
Cooling fan shall be automatically operated by a sequential operation.
The materials and surface finishing of radiator shall be selected in due consideration of possible rust proofing.
The diesel engine starting by battery.
The air intake system shall contain an intake air filter, ducts, expansion joints and the necessary fittings.
The exhaust gas system shall contain an exhaust gas silencer, tail pipe, gas duct, expansion joints and thermal insulation with cladding and necessary fittings.
One (1) intake air filter with auto-cleaning shall be provided for engine.
The type of intake air filter shall be subject to the approval by the Consultant.
One (1) exhaust gas silencer with tail pipe, located at outside of the powerhouse, shall be installed for each diesel engine.
The silencer shall be so designed that a noise level shall not exceed 110 dB (A) at one(1) meter away from the outlet of silencer under the specified operated condition.
The silencer shall be of a type that prevents collection of rainwater inside, and shall be provided with a drainage system at the bottom.
The tail pipe shall be directly mounted on the top of the silencer and located high enough to clear the roof of generator building.
2.7 Spare Parts and Maintenance Tools for Mechanical Works
Two (2) year spare parts including for overhaul shall be supplied.
Complete instructions to all maintenance equipment and instrument shall be in English.
The name, model number and source of consumable proprietary items (filters, etc.) shall be mentioned in the list.
Following items are minimum requirements and the Contractor shall provide, additionally, recommended items/numbers of spare parts.
Table 2.10.2-1: Spare Parts for Generating Facility
|
No. |
Part No. |
Description |
Quantity |
Remarks |
|
1 |
9060170260 |
SEAL RING (OBEN) |
18 |
|
|
2 |
0031845301 |
OIL FILTER |
120 |
|
|
3 |
0020920601 |
EASY CHANGE FILTER |
60 |
|
|
4 |
5419970545 |
SEAL RING INJECTOR |
18 |
|
|
5 |
007603008109 |
SEAL RING A8X11.5 |
46 |
|
|
6 |
0180941002 |
AIR FILTER |
10 |
|
|
7 |
5360180080 |
GASKET |
1 |
|
|
8 |
5419970645 |
O RING |
18 |
|
|
9 |
9060160080 |
WASHER CYL HD COVER |
32 |
|
|
10 |
0002034480 |
SEALING RING |
3 |
|
|
11 |
0052031775 |
THERMOSTAT INSERT |
3 |
|
|
12 |
007603008109 |
SEAL RING A8X11.5 |
46 |
|
|
13 |
0280743402 |
PLUG-IN PUMP |
18 |
|
|
14 |
3909970682 |
HOSE |
3 |
|
|
15 |
5220910080 |
GASKET |
1 |
|
|
16 |
5360180080 |
GASKET |
1 |
|
|
17 |
5360920080 |
GASKET |
1 |
|
|
18 |
5419970645 |
O RING |
18 |
|
|
19 |
5611871680 |
GASKET |
2 |
|
|
20 |
700336150007 |
RUBBER SLEEVE |
1 |
|
|
21 |
700368040002 |
RUBBER SLEEVE |
1 |
|
|
22 |
700368050001 |
RUBBER SLEEVE |
4 |
|
|
23 |
700368055009 |
RUBBER SLEEVE 55X70 |
1 |
|
|
24 |
700429090000 |
O-RING |
2 |
|
|
25 |
735038006107 |
HOSE LINE |
1 |
|
|
26 |
735038010111 |
HOSE |
1 |
|
|
27 |
9060160080 |
WASHER CYL HD COVER |
72 |
|
|
28 |
000000000671 |
CLAMP |
2 |
|
|
29 |
000000000672 |
CLAMP |
10 |
|
|
30 |
000000000681 |
CLAMP |
2 |
|
|
31 |
0000533558 |
GASKET (CYL HD VALVE |
36 |
|
|
32 |
0001423657 |
SEAL RING CONNECTOR |
8 |
|
|
33 |
0001840161 |
SEAL RING |
2 |
|
|
34 |
0002034480 |
SEALING RING |
3 |
|
|
35 |
000471024000 |
CIRCLIP |
36 |
|
|
36 |
000471065000 |
CIRCLIP |
1 |
|
|
37 |
000N05585/1 |
SEALING RING |
1 |
|
|
38 |
001474004018 |
GROOVED PIN |
2 |
|
|
39 |
0059974745 |
SEALING RING |
1 |
|
|
40 |
007603008109 |
SEAL RING A8X11.5 |
54 |
|
|
41 |
007603012111 |
SEAL RING A12X15.5 C |
6 |
|
|
42 |
007603014102 |
SEALING RING |
45 |
|
|
43 |
007603018101 |
SEAL RING A18 X 22 C |
6 |
|
|
44 |
007603026104 |
SEAL RING A26 X 31 |
3 |
|
|
45 |
007603026109 |
SEAL RING A26X34 |
1 |
|
|
46 |
007603030101 |
SEAL RING A30X36 |
8 |
|
|
47 |
007603038101 |
SEAL RING A38X44 |
7 |
|
|
48 |
007603042101 |
SEAL RING A42 X 49 |
3 |
|
|
49 |
007603052101 |
SEALING RING |
7 |
|
|
50 |
0080379019 |
TRAPEZRING |
18 |
|
|
51 |
0080379219 |
MINUTENRING |
18 |
|
|
52 |
0120371418 |
SLOTTED OIL RING |
18 |
|
|
53 |
0139973692 |
RIBBED BELT |
2 |
|
|
54 |
0189978947 |
OIL SEAL |
1 |
|
|
55 |
0229974948 |
SEAL RING CYL LINER |
18 |
|
|
56 |
1110180302 |
COVER |
1 |
|
|
57 |
200625906331 |
GROOVED BALL BEARING |
1 |
|
|
58 |
207603018301 |
SEALING RING |
6 |
|
|
59 |
23520341 |
SEALING RING |
2 |
|
|
60 |
271511030000 |
GASKET |
2 |
|
|
61 |
271511050000 |
GASKET |
1 |
|
|
62 |
271511060000 |
GASKET |
1 |
|
|
63 |
3909970682 |
HOSE |
3 |
|
|
64 |
4471870180 |
GASKET OIL DEL.TO TU |
2 |
|
|
65 |
5220130180 |
GASKET |
1 |
|
|
66 |
5220910080 |
GASKET |
2 |
|
|
67 |
5221870080 |
GASKET |
1 |
|
|
68 |
5229970092 |
V-BELT KIT |
2 |
|
|
69 |
5360150280 |
GASKET |
1 |
|
|
70 |
5360180080 |
GASKET |
1 |
|
|
71 |
5360300040 |
MAIN BEARING SET STD |
9 |
|
|
72 |
5360300060 |
CONROD BEARING SET S |
18 |
|
|
73 |
5360520050 |
BEARING BUSHING |
18 |
|
|
74 |
5360780080 |
GASKET |
8 |
|
|
75 |
5360920080 |
GASKET |
1 |
|
|
76 |
5369970047 |
OIL SEAL |
1 |
|
|
77 |
5410110059 |
SEALING RING LINER T |
18 |
|
|
78 |
5410160420 |
CYL HEAD GASKET |
18 |
|
|
79 |
5410330962 |
THRUST WASHER |
4 |
|
|
80 |
5410530532 |
VALVE SEAT INSERT (E |
18 |
|
|
81 |
5410531230 |
VALVE GUIDE (INLET & |
18 |
|
|
82 |
5410531731 |
VALVE SEAT INSERT (I |
18 |
|
|
83 |
5411420180 |
GASKET |
18 |
|
|
84 |
5419970345 |
O-RING |
18 |
|
|
85 |
5419970645 |
O RING |
18 |
|
|
86 |
5501871280 |
GASKET |
2 |
|
|
87 |
5611871680 |
GASKET |
3 |
|
|
88 |
700294015004 |
O-RING |
2 |
|
|
89 |
700327008000 |
GROMMET |
6 |
|
|
90 |
700327010000 |
GROMMET |
9 |
|
|
91 |
700327012000 |
GROMMET |
5 |
|
|
92 |
700327015000 |
GROMMET |
7 |
|
|
93 |
700327022000 |
GROMMET |
4 |
|
|
94 |
700327035000 |
RUBBER SLEEVE |
1 |
|
|
95 |
700327050000 |
GROMMET |
1 |
|
|
96 |
700336150007 |
RUBBER SLEEVE |
1 |
|
|
97 |
700368040002 |
RUBBER SLEEVE |
1 |
|
|
98 |
700368050001 |
RUBBER SLEEVE |
4 |
|
|
99 |
700368055009 |
RUBBER SLEEVE 55X70 |
1 |
|
|
100 |
700386095001 |
OIL SEAL |
1 |
|
|
101 |
700429009002 |
O-RING |
1 |
|
|
102 |
700429011001 |
O-RING |
1 |
|
|
103 |
700429013001 |
O-RING |
18 |
|
|
104 |
700429015000 |
O-RING |
1 |
|
|
105 |
700429019000 |
O-RING |
1 |
|
|
106 |
700429020003 |
O-RING |
1 |
|
|
107 |
700429027003 |
O-RING |
1 |
|
|
108 |
700429028003 |
O-RING |
2 |
|
|
109 |
700429035000 |
O-RING |
1 |
|
|
110 |
700429037001 |
O-RING |
2 |
|
|
111 |
700429040003 |
O-RING |
2 |
|
|
112 |
700429042002 |
O-RING |
2 |
|
|
113 |
700429048001 |
O-RING |
1 |
|
|
114 |
700429050003 |
O-RING |
4 |
|
|
115 |
700429055001 |
O-RING |
1 |
|
|
116 |
700429063000 |
O-RING |
2 |
|
|
117 |
700429075001 |
O-RING |
1 |
|
|
118 |
700429080001 |
O-RING |
1 |
|
|
119 |
700429090000 |
O-RING |
2 |
|
|
120 |
700429095004 |
O-RING |
2 |
|
|
121 |
700429150000 |
O-RING |
1 |
|
|
122 |
700429530000 |
O-RING |
1 |
|
|
123 |
700489050001 |
GASKET |
2 |
|
|
124 |
735038006107 |
HOSE LINE |
1 |
|
|
125 |
735038010111 |
HOSE |
1 |
|
|
126 |
735073004000 |
PLUG |
1 |
|
|
127 |
8370180080 |
GASKET |
1 |
|
|
128 |
8691510082 |
CARBON BRUSH KIT |
1 |
|
|
129 |
900288120003 |
CLAMP |
18 |
|
|
130 |
900288136004 |
HOSE CLAMP |
8 |
|
|
131 |
900288214001 |
HOSE CLAMP |
2 |
|
|
132 |
916016006201 |
CLAMP |
2 |
|
|
133 |
916016010203 |
CLAMP OIL FEED TO BR |
1 |
|
|
134 |
916016012201 |
CLAMP |
1 |
|
|
135 |
916016015202 |
CLAMP |
2 |
|
|
136 |
916016030202 |
CLAMP |
3 |
|
The mechanical maintenance tools listed as follows which will be utilized for inspection and maintenance of the generating facility.
Table 2.10.3-1: Equipment and Tools for Generating Facility
|
No. |
Item |
Quantity |
Remarks |
|
1 |
Standard Maintenance Tool Set for Engine |
1 set |
|
|
2 |
Special Maintenance Tool Set for Engine |
1 set |
|
|
4 |
Suction and Exhaust Valve Seat Grinding Machine |
1 set |
|
|
5 |
Tool Box (Steel) |
1 set |
|
|
6 |
Measuring Instruments (Caliper) |
1 set |
|
|
7 |
Measuring Instruments (Micrometer) |
1 set |
|
|
8 |
Hand Pallet (1.5 ton with Stopper) |
1 set |
|
|
9 |
1.0 ton Chain Block (2.5 m height) |
1 set |
|
|
10 |
2.5 tons Chain Block (3.0 m height) |
1 set |
|
|
11 |
Wire Ropes (6 mm diameter x 5 m length) |
1 set |
|
|
12 |
Wire Ropes (8 mm diameter x 5 m length) |
1 set |
|
|
13 |
Maintenance tools for Turbocharger |
1 set |
|
2.8 Training
Training is required for personnel who will be operating and maintaining the engine and auxiliary either on site and/or overseas.
3. GENERATOR AND ELECTRICAL AUXILIARY EQUIPMENT
Generator/Alternator
The generator sets well be directly coupled with a diesel engine shall be provided and installed together with all relevant auxiliary equipment.
The generator shall be of 3-phase, 3-wire, alternating current synchronous generator, horizontal shaft, open protected, salient or cylindrical pole with removal perforated sheet metal for cooling air and shall be capable of constant frequency operation.
The generator in conjunction with the exciter shall be designed to operate at all loads up to the maximum continuous rating.
The generator shall be so designed as to minimize the effect of torsional rotor oscillations due to system disturbances and rapid load change.
Colour-coding and phase identification shall conform to IEC standard.
Maker: MARATHON
Technical specification shall include but not limited to:
a.) Operating Duty Continuous
b.) Capacity 625 kVA
c.) Frequency 50 Hz
d.) Power Factor 0.8 (lagging)
e.) Rated Voltage 415 V
f.) Voltage adjustment range ±5%
g.) Cooling Air cooled
h.) Standard IEC standard
i.) Revolving speed Same as diesel engine
Voltage and Short Circuit Ratio (SCR)
The generator shall be capable of supplying the specified maximum output at rated speed and at rated power factor with a voltage variation between 95% and 105% of the rated voltage.
The generator shall be capable of withstanding the electro-magnetic and thermal stress resulting from maximum symmetrical or asymmetrical current at generator terminals caused by short-circuit condition.
Temperature Rise
The maximum temperature rise of the generator when operating continuously under the rated output at the specified ambient condition at the temperature of 40 deg. C shall not exceed in accordance with IEC
Over Speed
The rotor of the generator and armature of the AC exciter withstands an over speed of 20% for 2 minutes without mechanical injury.
Efficiency
The efficiency of each generator shall be not less than 94.0% at 500 kW with 80% lagging of the power factor.
AC exciter for brushless generator
The type of AC exciter shall be open protected (IP-20) and self ventilated type and rotor shall be overhung to generator shaft. Class of insulation of both armature and field windings shall be class F.
Deviation factor of a wave
The deviation factor of the line-to-line terminal voltage on open circuit at rated speed and voltage shall not exceed 10%
Insulation
The insulation of the stator and rotor windings of the generator shall be capable of satisfactorily withstanding power frequency tests in accordance with the requirements of IEC and fully withstand tropical conditions. Insulation of the stator windings and rotor windings shall be in accordance with IEC.
Stator
The stator frame shall be constructed of welded mild steel plates, being so designed as to have sufficient mechanical strength and to withstand electric shock.
The stator core shall be made up of silicon steel plate which is appropriate for magnetic characteristics and coated with an insulating epoxy for the prevention of eddy current and the punched plate elements are piled along the inner circumference of the stator frame from one and equipped with an air duct at each of the regular pile intervals.
The stator winding shall be formed of electric wire of insulation class F, and placed in a slot which has been formed in the inner periphery of the stator core and protected with an insulation material of class F.
Generator Leads
The neutral and output ends of each phase windings shall be brought out of the terminal box in the generator frame. External cables coming through flexible conduit shall be connected in the suitable protective covers.
Rotor
A solid flanged type half coupling suitable for bolting directly to the coupling face of the engine shaft shall be provided completely with all necessary coupling bolts and nuts.
The field core shall be made up of laminations of material having an exceedingly high coercive force for ease of voltage self-establishment. The slots in which the field coils are to be placed are formed in a number of slot groups, which corresponds to the number of poles or the poles, shall be secured to the revolving yoke by means of dovetail locking devices to ensure that no movement or subsequent loosening take place.
Efficient fans shall be fitted at the end of the rotor body and suitable air guides are to be provided for correctly distributing the air.
The necessary appliances to facilitate rotor withdrawal with the aid of the overhead traveling crane shall be provided.
Bearing
One (1) bracket sleeve bearing shall be provided with generator anti-coupling side. The bearing shall be of a pressure lubricated type and oil drain pipes shall be provided with pockets for thermometers and a suitable sight flow opening for observing the bearing oil flow.
Unbalanced Current
Generator shall be designed to withstand the 0.15 pu of maximum negative sequence component of current.
AC Exciter
The type of AC exciter shall be open protected (IP 20) and self ventilated type and rotor shall be overhung to generator shaft. Class of insulation of both armature and field windings shall be class F.
Exciter windings shall be insulated with class F materials in accordance with IEC. All insulating materials shall be non-hygroscopic and shall be impervious to the effects of a humid tropical climate.
The excitation system shall match with the generator rating and shall maintain the voltage of the unit within a tolerance of ±1.0% of the rated voltage by means of automatic voltage regulation.
The excitation system for the generator shall have sufficient capacity to enable the machine to operate at a range of ±5% of rated voltage at maximum load corresponding to the 10% overload rating of the engine.
Automatic Voltage Regulator (AVR)
Maker: MARATHON
A fast response continuously acting voltage regulator having a negligible dead band and characteristics enhancing the transient stability of the generator shall be provided for the generator.
The regulator shall be responsive to the generator terminal voltage and shall restore the generator output voltage within ±97% of the nominal pre-set level in a response time of less than one (1) second in case of sudden load change (0 to 100%, pf=0.4 below).
The AVR shall have a capability to adjust the generator voltage between a minimum of 90% of the rated voltage and a maximum of 110% of the rated voltage at no load condition.
Voltage adjusting rheostat operated by DC motor or static type voltage adjuster shall be equipped for remote control.
Accessories
Accessories shall be provided but not limited to the following:
one set of AC exciter and rotating rectifying device
one set of permanent magnet generator (PMG)
two sets of earthing clamps
three sets of current transformers for differential protection
six sets of temperature detectors and indicators for stator windings
one set of thermometer for bearing
one lot of anti condensation heater
one set of adjusting and foot liners
one set of sight glass for lube oil system
Internal Wiring
The control circuit wiring shall be 600 V grade polyvinyl chloride insulated wire (IV). Wire size and color shall be as follows
- AC control circuit: more than 1.25 mm2
(Yellow with color cap)
- DC circuit: more than 1.25 mm2
(Yellow with color cap)
- Earthing: 5.5 mm2 (Green)
- Electronic circuit: Manufacturer’s standard
Circuit wiring number tube or mark shall be provided on both wire ends.
Bus Bar
The bus bar shall be of single construction and air insulated throughout their length than can accommodate chosen generator from the table.
The bus bar and its connections shall comply with the requirements of IEC-1425 and shall be of copper and all jointing surfaces shall be silver or tin-plated with a rating a rating acclrding to the Generator rating.
Circuit Breaker
1) Type and Rating
The circuit breakers shall be of a vacuum type with surge protection device and electrically operated spring charge mechanism.
The circuit breakers shall comply with the requirements of IEC 2300 (1998) of IEC-60056 and with the relevant requirements of this Specification.
All circuit breakers shall be identical in arrangement and shall be interchangeable.
(a) Rated voltage: 415
(b) Rated current: Depending on the size of engine
(c) Interrupting capacity: 20 kA (1 sec)
(d) Operating sequence: 0-1 min.-CO-3 min-CO
(e) Control Voltage DC 110V and/or AC 110 V
2) Construction, Fitting and Associated Equipment
The circuit breaker shall be fixed to a welded steel carriage mounted on wheels, which engage with the rails in the base of the cubicle and facilitate location in the SERVICE or TEST positions.
Mechanism shall be fitted for inserting and withdrawing the circuit breaker for maintenance.
Each circuit breaker shall be fitted with an electrically operated spring action mechanism suitable for DC or AC 110 V service and shall have facilities for manually closing and opening the circuit breaker. The operating mechanisms of the circuit breaker shall have proven operational endurance, which conforms to the long service life of vacuum breaking part, and shall be so undulant as to ensure no necessity for frequent maintenance thereof. A mechanical operation counter and status indication shall be provided on each circuit breaker.
Each circuit breaker shall be provided with the necessary numbers of auxiliary switches.
Current Transformer
The rating and burden shall be according to the size of the engine and shall also conform to IEC 1201 or IEC-60185. The current transformers shall be of epoxy resin molded and have a bar or wound primary type according to the ratio required.
The secondary winding and core of each current transformer shall be encapsulated in epoxy resin, to exclude moisture and suitable to withstand dielectric and thermal and mechanical stresses in service.
The primary polarity designation and secondary terminals shall be clearly marked in accordance with IEC on the appropriate faces of each current transformer.
The accuracy class shall be as follows.
5P20 for generator differential relay and others are 5P10 for protection.
0.5 for measuring
Other basic specification shall be as follows:
Rated voltage: 415V
Rated secondary current: 1 A
Rated burden: Depending on size of the Genetator
Notes: The rated output of the current transformer shall be adequate to meet the load (burden) consisting of relays, meters, cables and allowance.
3.2 Low Voltage System
(1) General
The low voltage system consists of control/protection panels, low voltage power facilities, such as Station AC panel board, MMCs, Battery charger panel.
1) Construction
The panels and/or cubicles shall be of metal enclosed type with the following protection class:
Indoor installation: Minimum Protection class IP-21
Outdoor installation: Minimum Protection class IP-54
Hinged doors with key rock shall be provided on the front of panels and/or cubicles to way of access to all equipment. All doors shall be provided with suitable handle and one point latch.
Steel channel bases for attaching the panels to the concrete floor shall be provided.
The external wiring shall be, in principle, entering from the bottom of the panels. All control devices shall be mounted on the front of the panels and shall be principally accessible from the front.
Protection class of electric motor shall be as follows:
Indoor IP21
Outdoor IP-54
2) Applicable standard
Applicable standard shall be JIS, JEC, JEM and IEC or equivalent.
3) Bus bar
(a) Bus bars and bare conductors
The bus bars and bare conductors shall be made of cooper and shall be plated with tin or silver, but not plated for earthing bus bars.
Minimum size of earthing bus bar shall be 25 mm2
(b) Phase distinguishing color and arrangement of bus bars
The phase arrangement of bus bars, viewing from panel front, shall be as follows:
Phase 1 (Red) Left Top Front
Phase 2 (Yellow) l l l
Phase 3 (Blue) l l l
Phase N (Black) Right Bottom Rear
Generator Control Panel
The Generator Control Panel (GCP) shall be self-standing type and should be equipped with a synchronizing meter, measuring instrument, control switches, annunciation and other necessary devices for the plant.
2) Requirement for Construction
(a) The thickness of GCP shall not be less than 2.3 mm thick.
(b) The size of electric meter shall be 110 mm square with 250 deg. of square angle.
3) Accuracy of Indicating Meters
(a) Ammeter, Voltmeter: ±1.5% of full scale except for frequency meter
(b) Frequency meter: ±1.0% of rated frequency
(c) Watt hour meter: ±1.0% (IEC)
(d) Power factor meter: ±5% for electric angle 90 deg.
(e) Other indication meters ±1.5% of full scale
Remarks: Meters shall have black letters on a white background.
Cabling System, Electrical Materials and Grounding System
Cabling System
The control and instrument cable shall be considered to prevent influence by induced voltage, which may cause a malfunction of the control device. If necessary, sealed type cable (CVVS or equivalent) shall be applied.
The LV cables shall be put on trays for indoor and conduit pipe for outdoor cabling which shall be buried in the ground.
Conductor
The conductor shall be not less than seven stranded, except special cables, annealed copper.
The construction of the conductor shall be of a compacted circular multi-or single core type. The cross-sectional area of the conductor shall be capable of carrying the required load safely and properly considering the continuous and starting current.
Insulation
The insulation material shall be extruded cross-linked polyethylene in accordance with IEC of low dielectric loss, high dielectric strength, and low thermal resistivity and long term stability. The curing process shall be of the dry method. It shall be free from contamination by oil, chemicals and moisture.
The cable shall be selected with due consideration to load requirements of each feeder and short-circuit current capacity of the cable in order to prevent premature insulation failure. The insulation of conductor shall be numbered or color-coded in accordance with IEC.
For motor circuits, the cables shall have a current-carrying capacity of at least 115% of the full load current rating of the motor after application of the appropriate de-rating factors.
Control and Instrument Cables
Control and instrument cables shall have a copper conductor with PVC insulation, rated 600 V, PVC overall sheath, and jacket type unless specified otherwise. All cables shall be stranded copper conductors, with the insulation color or numbering, where applicable.
The minimum size of the control cables shall be as follows:
For CT circuit 4mm2
Other circuit 2mm2
The wiring for the circuits adversely influenced by a stray electric field shall be provided with suitable shielding.
PVC insulated control cables shall be used in the area of installation where the ambient temperature is normally lower than 40 deg. C or may rise or a short period above 40 deg. C.
Grounding Wires
Grounding wires shall be of stranded annealed copper conductor. Application standard for grounding wires inside panel shall conform to IEC.
Grounding system shall be extended, but not limited to, for all facilities or panel boards, control panels, transformers, cable trays etc, by using copper conductors to connect all new equipment, electrical neutrals, steel bases, electrical boxes and of motor and/or electrical devices, and shall be connected to existing Grounding system at least 2 points.
Design
The design of the grounding system shall meet the requirements of IEEE-80.
Installation
Copper grounding conductors shall be tinned when in the vicinity of galvanized steel and at equipment grounding terminals.
Grounding conductors shall be laid where possible within the concrete ducts. Where conductors cross the concrete foundations for the connection to the equipment it shall be installed at flat and fastened to the concrete.
Equipment Grounding Within Panels
Required and should conform to IEC.
4. Others
4.1 Fire fighting system according to International Standard (trolley to handheld fire extinguishers)
4.2 Piping work
