CONTENTS
1.0. SCOPE
2.0 DEFINITIONS
3.0 RESPONSIBILITY
4.0 STATEMENT OF COMPLIANCE
5.0 SAFETY
6.0 PREFABRICATED SUBSTATION
6.1 TOOLS / EQUIPMENTS
6.2 TEST EQUIPMQNTS
6.3 INSTALLATION PROCEDURE
6.4 INSPECTION & TESTING PROCEDURE
6.4.1 INSPECTION OF PREFABRICATED SUBSTATION
6.4.2 TESTING OF PREFABRICATED SUBSTATION
1.0 SCOPE
This method statement covers the manufacturing, supply, installation, pre-commissioning test, factory testing, marking, transportation to site, installation, site testing carried out at the source, procedure and instructions for materials inspection upon arrival at site, the requirement and instruction for executing the activities listed under this section up to pre-commissioning, commissioning and final hand over of the works.
The 11/0.4 KV prefabricated substation equipped with
Ÿ Fully enclosed vandal and weather proof housing made of Alu Zinc
Ÿ 11 KV RF6 Gas insulated RMU equipped with
a) Vacuum or SF6 breaker with self powered protection for transformer feeder
a) Load break switches for incoming / outgoing feeders with motor drive provisions.
Ÿ 500KVA hermetically sealed 11/0.433 transformer (oil type)
Ÿ 11 KV control and protection equipment
Ÿ CT’s and VT’S
Ÿ 0.4 KV Flange connected Feeder pillar.
Ÿ Indicating instrument
2.0 DEFINITIONS
SEE – Site Electrical Engineer, ST – Survey Team, S/s – Substation, TF – Transformer, FP – Feeder Pillar, TRM – Tee Ring Main unit, QRM – Quad Ring Main unit, RMU – Ring Main Unit, P/U – Package Unit, CT – Current Transformer, VT – Voltage Transformer.
3.0 RESPONSIBILITY
This is the responsibility of the Site Electrical Engineer and safety officer to ensure that this method Statement and Safety Procedures are followed during the execution of the work.
4.0 STATEMENT OF COMPLIANCE
We hereby confirm that we shall comply all the procedures and execute the subject works as per the fullest requirement, satisfaction of end user and specifications
A constant supervision of works shall be done by qualified Electrical Engineer and certified safety officer.
Material shall be used for assembly of Prefabricated S/s are designed in accordance with the standards and system characteristics as stated in corporate ADDC specifications
5.0 SAFETY
1) All work forces to be involved in execution of the Switchgear errection shall undergo safety induction training before starting the site activities. Prior to the commencement of any activities, the workforce will receive an induction talk on the project site safety requirements.
2) The necessary permits that may be required to work near existing services will be obtained. Any special conditions imposed upon these permits will be implemented.
3) The use or restriction of specific Electrical & mechanical equipment, whilst locating or excavating near the existing cables and other services will be implemented. The contractor shall utilize the manpower whomever obtain security passes. Company shall be responsible for all activities and interfaces related to this project
6.0 PREFABRICATED SUBSTATION
6.1 TOOLS / EQUIPMENTS
· Hand tools for Electricians
· Lifting crane
· Fork Lift
6.2 TEST EQUIPMENT
· Digital multimeter.
· Ductor Tester
· Clamp on Ammeter (Digital)
· High pot Tester Set (with all accessories)
· 1 KV Insulation Resistance Tests
· 5 KV Insulation Resistance Tests
· Secondary injection set
· Phase rotation meter.
All the testing instruments will have calibration certificate valid for minimum six months. Calibration certificate can be verified during testing.
6.3 INSTALLATION PROCEDURE
· The prefabricated substation will be installed in place after completion of all civil work in prefabricated substation room i.e. Concrete plinth, Trenches, Fence, channels external wall etc…
· Installation of the prefabricated substation will be co-ordinate with civil and other teams and all other activities.
· Transformer shall be located at the middle of the prefabricated substation
· TRM and the FP will be placed at each end of the prefabricated S/s.
· Rails for package unit rollers will be installed
· The pre fabricated S/s will be unloaded directly onto position as per approved Layout drawings.
· Align and level the pre fabricated S/s.
· Fix the prefabricated S/s on the rail as per manufacture recommendation.
· Gladding and proper termination for HV.
· Gladding and proper termination for
· Ground the prefabricated S/s as per approved Earthling Layout.
· Testing of the prefabricated S/s as per Inspection and Testing procedure
· Termination of HV / LV Control and Instrument cables. Testing of HV cable shall be carried out after termination is installed and before the cable is finally bolted to the HV terminal of the transformer
· Installation shall be carried out fully complying with manufacturer’s recommendation and procedures.
· Installation check list will be submitted to Engineer for approval.
· Tighten the bolts with torque wrench as per manufacturer recommendation
· Necessary site inspection requests shall be submitted to Engineer during the above activities at site.
· Maintenance procedure / Instructions shall be furnished to maintenance team / Engineer during delivery of materials at site.
6.4 INSPECTION AND TESTING PROCEDURE
6.4.1 INSPECTION OF PREFABRICATED SUBSTATION
· Check prefabricated S/s for any Physical damage
· Check nameplate rating and tagging
· Check if installation is made as per approved drawing and in line with vendor recommendations
· Check Cable glanding and termination
· Check operation and condition of tapping switch in the transformer
· Check Earthing for the prefabricated S/s.
· Check Cable and Cable Tray supports.
· Check protection devices i.e. winding temperature switch / thermometer
· Check door locks for HV and LV Terminal boxes
6.5.1 TESTING OF PREFABRICATED SUBSTATION
The following Test of the Prefabricated S/s will be carried out:
· Insulation Resistance winding
· Megger of winding HV side 5000V megger
· Measurement of winding resistance
· Measurement of impedance voltage on all tap’s for the transformer
· Measurement of no load loss
· Measurement of load losses at principle tap and extremes
· Induced AC voltage withstand voltage test with measurement of partial discharge
· Separate source AC voltage withstand voltage test
· Measurement of Voltage ratio between primary and secondary winding
· Check operation of winding temperature switch / indicator
· Check vector group by voltmeter method
· Check phase sequence
· Check polarization index
· Applied over voltage test at 2000V, AC, 60 sec. on wiring and supervisory equipment
· Check the earthing details of the prefabricated S/s and the earthig value. (The value of earthing is less than 2Ω).
· ITP forms for SF6 Gas filling and pressure testing could not be provided, as such test shall be carried out at factory (i.e, Routine test). Routine test certificate shall be submitted during the material delivery at site.
· Any other test as stated in ADDC Specs
All above Tests shall be recorded in Pre-commissioning Test forms.
