Power Plant ELECTRICAL WORKS - Power Supply System

 Power Plant

       

ELECTRICAL WORKS

Power Supply System

a]         The Contractor shall provide AC power supply system at  end Fuel Gas Metering station comprising of complete 480V, 60 Hz, 3 phase, 4 wire switch rack of outdoor type of adequate capacity. The switch rack shall have incoming and outgoing circuit breakers.

 b]         The bus bar, the incoming circuit breaker, and all outgoing circuit breakers shall be in stainless steel weatherproof enclosures.

c]         The switch rack and all its incoming & outgoing circuits shall be constructed as per requirements of the latest version 

d]         The Contractor shall provide the protection and relaying equipment required.

e]         The current ratings shall be referred to 500C ambient conditions with due regard to environmental conditions at site.

f]          The construction shall be such that various components are segregated electrically from each other.  All faults occurring in any of the individual sections are to be restricted to that area except for bus bar.

g]         All secondary wiring shall be arranged and protected to prevent its damage by arcing or by mechanical effects.

h]         Incoming supply to the switch rack shall be taken from the nearby switchboard/MCC of the PP- and shall meet all load requirements of the terminal including lighting, cathodic protection, and ESD valve shut down power requirements etc.

 All cables, and related works required in this regard shall be provided by the Contractor.

i]          The electrical power requirements for the tie-in point pp end and cathodic protection of the line shall be met from solar panels, their back-up batteries and distribution panel. The solar panels, charge regulator and batteries shall be designed in accordance with the requirements and shall meet all terminal load requirements. 

The batteries shall be of sealed type, maintenance-free, and shall be rated to meet all electrical requirements of the terminal.

    Lighting System and Socket Outlets

a]         The works at PP end terminal shall include but not be limited to the following: 

480V – 208V/120V, 3 phase

, indoor dry type floor mounted transformers located inside the control room for all lighting,

 socket outlet and control requirements as shown on the Drawing.

i.          One (1) 208/120V, 3 phase indoor lighting and socket-outlet panel board installed inside control room.

ii.          One (1) lighting panel board for outdoor lighting requirements installed outside along with photoelectric switch and a manual-off-auto selector switch.

iii.         Indoor, outdoor lighting and socket outlets requirements for all areas.

b]         The lights for the tie-in point at pp shall be provided “on job” basis only, and their voltage rating shall match the voltage of the storage batteries. Each light will be controlled by an individual switch which will normally be kept off either manually or by a cabinet door operated switch.

c]         The lighting system shall comply with the requirements of pp.

d]         The Contractor shall submit calculations for minimum illumination levels, voltage drop and wiring sizing, etc. The maximum voltage drop from the transformer to any fitting shall not be more than 3% of normal voltage.

e]         The transformer shall have 25% spare capacity available after commissioning and acceptance of the Project, whereas sub-boards shall have 20% spare fully equipped feeders of adequate ratings for future use. The Contractor shall ensure that equipment, lighting fixtures, and outlets used are suitable for area where being installed and lamps used are commercially available.

f]          Emergency lighting shall be provided in the selected fixtures and shall comprise of battery packs of suitable ratings.

    Grounding System

a]         The Contractor shall provide a grounding system for- PP- end

 installations comprising of underground network, above-ground network and equipment connections to the grounding system.

b]         The design, fabrication, execution of works, inspection and testing of the grounding system shall be by the latest edition.

c]         A sub soil earthing system comprising of bare copper conductor and earthing rods shall be provided.

 The embedded conductor shall be connected to the above-ground network and also to the reinforcing bars of the equipment foundations.

    Cables/Wires

a]         The Contractor shall provide all cables, wires, their laying and their terminal connections to the equipment.

b]         All cables/wires shall be XLPE insulated and thickness of insulation.

c]         Design ambient temperature for cables/wires shall be 50ºC and when laid in underground ducts the earth ambient of 35ºC at one meter below grade shall be considered.

d]         The earth's thermal resistivity of 200ºC cm/watt shall be considered.

e]         Conductor material for all cables/wires shall be stranded copper in accordance with IEC 60228.

f]          The outer sheath shall be of PVC with flame retardant additives as per IEC 60332 and heat, oil, moisture and corona resistive.

 The cables shall be resistant to solar radiations, bacterial action, insects and rodents.

g]         The fire-resistant cable shall be in accordance with IEC 60331.

    Data Sheets

Reference is made to the forms of Bidder’s Data Sheets of these Specifications. The blank forms contained therein shall be completely filled in and submitted together with the Bid.