080121-08MN006-Sabina Hackett River Project Proposal ... - NIRB

Project Description2.6.1.5 Site Power DistributionThe electrical distribution will consist of switchgear, transformers, starters and feeder breakersfor the motor and non-motor loads in common lineups. Lighting and small power applicationswill be fed from transformers and power panels as required, and will be located in the electricalrooms.Equipment utilization voltages will be obtained from step-down transformers. Plant substationsshall be located near major concentrations of electric loads.Cabling will use armoured, jacketed copper conductors with ground, shielded cables in heavyduty aluminum ladder tray systems. Transformers will be located in the process area electricalrooms and will be dry type.Electrical coordination will be completed to minimize power interruption on operation of powersystem protective relay operation.Plant equipment utilization voltages will be:Plant EquipmentGrinding Mill Motors, HoistsAll drives over 200 HPAll drives 0.5 HP – 200 HPMotors with VFD up to 500 HPMotors with VFD over 500 HPSmall drives below 0.5 HPElectrical Heaters over 1.8 kWElectrical Heaters up to 1.8 kWLightingSmall power andinstrumentationHeat tracing: ShortlengthsLong lengthsWelding ReceptaclesVoltages4.16 kV 3 phase high resistance grounded4.16 kV 3 phase high resistance grounded600 volt 3 phase high resistance grounded600 volt 3 phase high resistance ground(maximum HP rating to be determined at time of order)4.16 kV 3 phase high resistance grounded120 volts 1 phase solidly grounded600 volt 3 phase high resistance grounded120 volts 1 phase solidly grounded347 volts 1 phase solidly grounded120 volts 1 phase solidly grounded120 volt 1 phase or 208 volt 3 phase solidly grounded347 volt / 600 volt 1 or 3 phase solidly grounded600 volt 3 phase high resistance grounded2.6.1.6 Emergency Standby PowerThe diesel generation facility is split into two parts to provide capacity for site emergency backuppower requirements. In remote Arctic locations, backup power is required for survival in adverseweather conditions. In the event of loss of one diesel power plant, the other will be able toprovide the site emergency electrical power and process building heating requirements. Thiseliminates the need for smaller, emergency power units to be strategically located around theprocess plant.In addition, an emergency power diesel genset will be installed adjacent to the camp to providebackup power in the event of a failure of the distribution system.January 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 2–25 Rescan Environmental Services Ltd. (Proj. #833-2)