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China National Electric Wire & Cable Imp./Exp. Corp. |
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9 ELECTRIFICATION 9.1 General 9.1.1 All electrical equipment and materials shall be of high quality and reliable. In order to avoid corrosion of H2S, materials used for producing these equipments should be corrosive resistant. Aluminum is preferable than copper for usage, if copper is requisite in these equipment as material, then corrosive resistant coating materials are applied on the surface which would contact with H2S, the material or metal elements for coating can be zinc or other suitable materials. 9.1.2 All electrical equipment shall, if not otherwise specified, comply with the applicable following codes, standards and recommendations: * IEC International Electrotechnic Commission * GB China National Standard 9.2 Scope of Supply The 2x6MW Geothermal Project will comprise two identical 6MW; 20kV substation and common auxiliaries. These electrical equipment will be supplied: * Generator * Diesel generator * Step up transformer * Unit auxiliary transformer * 20kV switchgear * 6.3kV switchgear * 0.4kVMCC * Control and relaying * Uninterruptible power supply system (UPS) * Plant DC system * Communication system * Power cable and control cable * Cable tray * Lighting system * Lightning protection and grounding * Spare * etc. 9.3 Power system 9.3.1 One 20kV busbar will be built in the mill extension. One outgoing line connected to the PLN gird on overhead. Two incoming lines connect two step-up transformers. The transformers are 20/6.3kV 10MVA. 9.3.2 Two auxiliary transformers will be build for the power plant service motors and public power. Two auxiliary transformers will be standby each other. 9.3.3 An emergency power supply system consisting of 60kW diesel generator will provides power to necessary loads for safe and accident operation. 9.3.4 Grounding system High voltage 20kV Neutral isolated Medium voltage 6.3 kV Neutral isolated Low voltage 400/230V Neuter grounding solid Detail see electrical single line drawing 9.4 Design documentation and diagram of the electrical engineering Drawings and documents in the Supplier scope are as follows: * Document schedules. * Main electrical single line diagrams. * Single line diagrams for switchgears. * Cable tray layouts. * Cable layouts and elevations for power, control and signal cables. * Cable schedules and connection lists. * Electrical room equipment, transformer arrangement and hole openings. * Motor control center (MCC) schematic diagrams. * Switchgear interconnection diagrams. * MCC interconnection diagrams. * Interlocking logic diagrams. * Motor lists. * Electrical bill of materials. * Operation, maintenance and installation instruction manuals. * The setting values and calculation for protection relays. * Calculation for short circuit and voltage drop. * Test report for all electrical equipment. Detailed specification for each and individual equipment. * Grounding system engineering. * Lightning protection design. * Lighting design engineering. * Battery and battery capacity design. * Fire alarm system design * Lighting layout design. * Emergency lighting layout design. * All drawings, data, calculations and manuals will be written in English. 9.5 Power consumption of plant motors The estimated installed power of the project will be 2MW, the estimated demand power will be 1.6MW. The estimate emergency power will be 50kW. 9.6 Protection relay and automatism equipment The protection relays and automatism set shall be the microcomputer type. The following Protection relay and automatism equipment will be installed: 9.6.1 Generator * Differential * Earthing fault (one site grounding for stator) * Over voltage * Over temperature * Over current * Excitation fault * Under voltage * Over load * Automatic manual synchronizing system * Automatic adjust excitation * Others 9.6.2 20kV outgoing line * Current and voltage fast protection 3ph * time-delay current protection 3ph * Over current protection 3ph * Earthing fault * Auto reclosing relay * Automatic and manual synchronizing system 9.6.3 20/6.3kV step up transformer * Differential * Over current * Over load * Earthing fault * Buchholz protection * Over temperature
9.6.4 6.3/0.4/0.23kV transformer * current fast protection 3ph * Over current protection 3ph * Earthing fault * Over temperature 9.6.5 Plant 0.38kV service motor The main service plant motors will install microcomputer motor protection device. * current fast protection 3ph * Over current protection 3ph * Over load protection * Long starting time protection * Earthing fault * Low voltage * Others 9.8 DC System DC system will comprise of the following: * Stationary batteries (220V DC) * Battery charger connected to the LT switchboard * 230V DC distribution switchboard * Other accessories The battery shall be Nickled-Cadmium type. The battery capacity will be about 150AH. The battery charger shall be monitor mode and automatic charging mode. 9.9 Lighting 9.9.1 Lighting voltage shall be 220V, single phase, 50Hz 9.9.2 Illumination levels * 300 lux in control rooms and offices * 200 lux in switchgear room and MCC room * 200 lux in generator room and loading areas * 50 lux on stairs and platforms * 25 lux in the yard 9.9.3 Luminaire Fluorescent lamp for control room, offices and some indoor working areas. Incandescent lamp for some emergency lighting, small room, etc. Color-improved mercury or similar types with low energy lights for high building or structure, large working areas, flood lights. etc. 9.9.4 Emergency lighting The emergency lighting unit incorporated with battery-rectifier, normally will be used in process departments and other buildings. The emergency lighting for control room and other important places within the power plant shall consists of incandescent lamps fed from the 220V DC battery unit. 9.10 Grounding The 20kV and 6.3kV system normally will be neutral isolated. The low voltage power distribution system normally will be neutral solid grounded (TN system). The overall resistance shall not exceed 1 ohm for any path to grounding. Conductors may be bare aluminum wire or galvanized steel. 9.10.1 Communication and Uninterruptible power supply system (UPS) Any required equipment and communication service will be provided. One set of uninterruptible power supply system (UPS) (3kVA ) will be provided 9.10.2 Technical specification for electrical equipment All enclosure and equipment shall be tropicalized. Detaisl see technical Schedules A. 20kV switchgears and 6kV switchgears Switchgear shall be complete with protection and other necessary metering, testing, operating devices and special tools. The space heater shall be installed. B. 20kV Circuit breaker and 6kV circuit breaker The circuit breaker consist of spring charging of manual and motor driven. The control voltage of the circuit breaker is 220DC. C. 380V Switchboard The circuit breakers in the switchboard shall be of draw out or fixation type. The Cubicles shall be arranged in free standing vertical assemblies with ten small size starters at most in a single stack. The bottom enclosure of each stack should not contain a starter, it may be used for connections and fittings. The center itself be sized for future expansion. The starter and all controls for each motor shall be in single enclosure. An automatic space heater shall be installed. D. Transformers The step up transformers will be oil immersed type. The unit auxiliary transformers will be try type. Detail see technical Schedules. E. Motor Low voltage AC Motor Most of the motors will be squirrel cage induction type, and normally started directly on line.Soft-starter will be supplied as necessary. Motors from 0.37 to 200kW shall be 380V. * Type * Rated voltage 380V * Frequency 50Hz * Insulation class F * Protection class IP54 Cables and Wiring All conductors that are exposed to air shall be aluminum or zinc coated copper. Armored cable shall be used except where specific applications require conduits. Low voltage power cable * Type Series YJLV * Rated voltage 1kV * Insulation XLPE 2. High voltage power cable * Type Series YJLV * Rated voltage 6kV * Insulation XLPE 3.Control cable * Type Series KVV * Rated voltage 0.5kV * Insulation PVC G. Spare parts The Vender shall supply spare parts for two years operation. |