NATIONAL ELECTRIC POWER COMPANY (NEPCO). TENDER NO.1/2017. FOR THE SUPPLY OF INSULATORS AND FITTINGS. FOR THE FOLLOWING.
NATIONAL ELECTRIC POWER COMPANY (NEPCO) TENDER NO.1/2017 FOR THE SUPPLY OF INSULATORS AND FITTINGS
FOR THE FOLLOWING LOT(A): QATRANA – AMMAN WEST 400kV OHTL LOT(B): SAMRA – AMMAN WEST 400kV OHTL 6. Technical Specification 6.A
SCOPE This specification covers the design, manufacture, testing, packing, supply, (CFR) delivery to Aqaba Docks in Jordan and guarantee (maintain) the insulator types and all fittings to be used for the following OHTL's:
Lot(A) : 400kV overhead, double circuit, three phases, two OPGW Earthwires and Triple Conductors per phase, transmission line between Qatrana substation and Amman West Substation for a total length of approximately 110 kms of line route length, which is financed by NEPCO. Lot(B) : 400kV overhead, double circuit, three phases, two OPGW Earthwires and Triple Conductors per phase, transmission line between Samra substation and Amman West Substation for a total length of approximately 75 kms of line route length, which is financed by NEPCO. Insulators type and material The insulators shall be Composite, suspension and tension insulators. 6.B
Physical Characteristics : Tenderers are requested to fill and submit all technical and price Schedules for the following suspension, and tension insulator sets of total minimum creepage path of 15960mm as specified in addition to other items and all pins shall be equipped with Zinc sleeves :-
1.
Composite Insulator
1.1
Composite Insulator shall consist either of Uniform or Alternating sheds and the housing shall be directly molded or casted in one or more several pieces on the core according to schedule No.1 item 14 and the required standards.
1.2
Core of a composite insulator: It shall be designed to ensure the mechanical characteristics, The core will consist of glass fibers which are positioned in a resin based matrix in such a manner as to achieve maximum tensile strength.
12.1
Core diameter : The core diameter shall be either : The geometric diameter of a core of circular section, or, 1
2
12.2
12.3
A / for a core with non-circular cross section of area A.
Housing and shed of a composite insulator : It shall provide the necessary creepage distance and protect the core from the weather. An intermediate sheath made of insulating material is apart of the housing. A shed shall be a projecting part of the housing intended to increase the creepage distance. The sheds can be with or without ribs. Interfaces of composite insulator: An interface will be the surface between the different materials or parts of the composite insulator. Various interfaces occur in most composite insulators , e.g.: - Between glass fibers and impregnating resin ; - Between filler particles and polymer. - Between Core and housing. - Between various parts of the housing ; between sheds, or - Betweens sheath and sheds ; - Between housing, core and metal fittings.
12.4
Metal fittings of a composite insulator: The metal fittings shall be intended to connect to a supporting structure, or to a Conductor, or to an item of equipment, or to another insulator.
12.5
The connections between the End fittings of the Suspension and Tension Insulators and the Tower plate should be move freely to avoid any broken at the end of the connection.
12.6
Spacer dampers should have a rigid frame, at the corners of which the connection with the conductors should be provided by means of hinges with clamps, the hinges should lines with rubber elastic cushions make of silicon or Ethylene Propylene Diene Monomer (EPDM) Rubber.
12.7
Connecting zone: zone where the mechanical load is transmitted between the insulating body and the end fitting.
12.8
Coupling: The coupling shall be the part of the metal end fitting which transmits the load to the accessories external to the composite insulator.
12.9
Tracking: Tracking shall be an irreversible degradation by formation of paths starting and developing on the surface of an insulating material. These paths are conductive even under dry conditions. Tracking can occur on surfaces in contact with air and also on the interfaces between different insulating materials.
12.10 Treeing: Treeing shall be an irreversible degradation consisting of the formation of microchannels within the material which can be conducting or non- conducting. These microchannels can 2
progressively extend through the bulk of the material until electrical failure occurs. 12.11 Erosion: Erosion shall be an irreversible and non-conducting degradation of the surface of the insulator that occurs by loss or material. This can be uniform, localised or tree – shaped.
12.12 Chalking (flouring): Chalking shall be the appearance of some particles of the filler of the housing material forming a rough of powdery surface. 12.13 Crazing: Crazing shall be made of surface micro – fractures of depths approximately 0.01 mm to 0.1mm. 12.14 Crack: Any surface fracture of depths greater than 0.1mm. 12.15 Hydrolysis phenomena: Hydrolysis phenomena, due to water penetration in liquid form or as water vapour, can take place in the materials of the composite insulator which can lead to electrical and / or mechanical degradation. 12.16 Specified mechanical load (SML): The SML shall be the load specified by the manufacturer which is used for mechanical tests. 12.17 Routine test load (RTL): The RTL shall be the load applied to all assembled composite insulators during a routine mechanical test. 12.18 All Installation Criteria for Spacer Damper and Vibration Damper should be submitted with the offer. 6.C
STANDARDS The following or equivalent standards shall be considered in the design or testing of the offered insulators. These standards shall be applied in part or whole to the offered insulators. IEC
60815
-
IEC IEC
61854 61897
-
IEC IEC
60060 60120
-
IEC
60305
-
Selection and dimensioning of high voltage insulators intended for use in polluted conditions. Requirements and Tests for Spacers. Requirements and Tests for Stockbridge Type Aeolian Vibration Dampers. High Voltage Test Techniques Ball and socket coupling of string insulator units. Characteristics of string insulators of cap and pin . 3
IEC
60372
-
IEC IEC
60383 60437
-
IEC
60575
-
Thermal-mechanical performance test and mechanical performance test on string insulator units .
IEC
62217
-
Polymeric insulators for indoor and Outdoor use with a nominal voltage > 1000 V.
IEC
61109
-
Composite suspension and Tension Insulators for a.c. systems with a Nominal voltage greater than 1000kV
BS EN 1562
-
Malleable Iron – Castings .
BS EN ISO 1461: 2009
-
Hot dip galvanized coatings on iron and steel articles .
Locking devices for ball and socket couplings of string insulator units . Tests on insulators . Radio interference test on high voltage insulators.
BS EN
10083
-
Forged Steel .
BS EN
1563
-
Iron castings with spheroidal or modular graphite (ductile).
BS EN
12163
-
copper and copper Alloys (Table 8 for chemical composition and mechanical properties of phosphor bonze for pins or locking devices).
IEC
61284
-
the requirements and tests of Fittings
BS
3288
-
Test of Fittings.
6.D Testing The Contractor is required to provide all facilities to enable the Employer’s representative to carry out the necessary inspection and testing of the insulator sets and their materials. The costs of all tests during manufacture and preparation of test records are to be borne by the Contractor. All costs associated with the witnessing of the tests by the Employer’s staff, which comprises visas, airtickets of economic class, hotel accommodation, transport and all meals shall be filled in by the Tenderers in the relevant item of detailed price schedules. Payment will be for the successful test only. 4
If by the Employer’s decision third party testing will be conducted (Routine & Sample Tests), the Contractor will conduct the required tests by the Employer through any International Approved laboratories and all expenses of all tests will be incurred by the Contractor. Testing Instruments shall be approved and shall, if required the Employer’s representative, be calibrated by the National Physical Laboratory or such other body as may be approved, at the expense of the Contractor. II. Composite insulator suspension and tension string of each shall be subject to the following tests in accordance with the provisions of IEC publications 60383, 60437 and 61109 or such other standards as may be approved :-
A) Design Test: this test must have been done at Approved Third Party Laboratory and should be attached with the offer as follows:
1) Tests on interfaces and connections of end fittings: - Prestressing. - Water immersion pre-stressing. - Verification Test. - Visual examination. - Steep front impulse voltage test - Dry power frequency voltage test. 2) Tests on shed and housing material: - Hardness test. - Accelerated weathering test. - Tracking and erosion test. - Flammability test. 3) Tests on the core material: - Dye penetration test. - Water diffusion test. 4) Assembled core load time test: - Determination of the average failing load of the core of the assembled insulator. - Control of the slope of the strength time curve of the insulator. B) Type test: Third party Full Type Test according to tender requirement will be conducted and witnessed by two inspectors from NEPCO's engineers at one of the following international independent laboratories (KEMA, CESI, IPH Germany, ETH Switzerland, SAG Germany and Kinectrics Canada) and /or carried out at one of international accredited laboratory has a certificate of (ISO/IEC 17025) and approved by NEPCO with the presence of both NEPCO and representative from 5
above mentioned laboratories (KEMA, CESI, IPH Germany, ETH Switzerland, SAG Germany and Kinectrics Canada). - Dry Lightning Impulse withstand test: Dry withstand positive and negative polarity. - Wet Power frequency withstand tests :wet withstand tests shall be on complete insulator strings including string fittings and dampers and any other fittings attached to the Conductors in service and shall be made with and without arc horns. To achieve this a set of fittings for each insulator string will be forwarded to the insulator manufacturer by NEPCO or his selected fittings manufacturer for assembly into complete strings. - Wet switching impulse with stand voltage test. - Mechanical load time test. - Corona and RIV Tests which will be according to the latest relevant IEC standards. For these tests, single unit RI test will be required on the insulator discs which are used to make up the complete string. The two noisiest discs should be pleased at the line end, but otherwise the order may be random the RIV value shall be not less than 100μV/m. - Short circuit test: For the value of 40 kA (RMS) for 1 second. C) Sampling test: This test shall be carries out at the manufacturer’s works and as follows: - Verification of dimensions. - Verification of end fittings & locking system. - Verification of specified mechanical load (SML). - Galvanizing test. D) Routine test: This test shall be carried out at the manufacturer’s works and as follows: - Identification of the composite insulators. - Visual examination. - Mechanical routine test. The electrical field calculation should be provided with the offer and the maximum electrical field value should be compared with the voltage of aging test where the value of maximum electrical field should be less than the value of aging test. In case that Testing by third party (International Testing companies which should be approved by NEPCO) decided by the Employer in the place of manufacture, the Contractor will conduct on his own expense all the tests required by the Employer. 6.E
MARKING Every insulator body shall have a durable and legible trade mark and year of manufacture as well as the rated combined M & E strength in Kilo Newton & Kilo Volts respectively. 6
6.F
PACKING The whole of the insulators shall be packed in non returnable cases. The cases shall be convenient for ocean and overland transportation. Packing cases shall be strongly constructed and in no case timber less than 25mm in thickness is to be used. The contents of the packing cases shall be securely fastened in position with struts or cross battens. Aluminum, Plastic or PVC, name plate shall be fixed to each case and clearly marked with the following:- Contract No. - Number and size of insulators. All packing will be inspected before shipment.
6.G
SHIPPING MARK FORM : is attached.
6.H
INSULATOR AND CONDUCTOR FITTINGS Routine and sample mechanical tests shall be carried out on fittings in accordance with the appropriate section of BS. 3288 part 1 or such other standard as may be approved.
6.I
TENSION CLAMPS AND JOINTS Samples (number of samples will be according to relevant IEC standards) of the following: i. Suspension clamps. ii. Tension joints. iii. Tension clamps. iv. Partial tension fittings. v. Repair sleeves. vi. Insulator protective fittings. vii. Vibration dampers. viii. Non tension joints. Shall be submitted to mechanical and electrical type tests which will be done according to the latest relevant IEC standards in laboratories mentioned in the technical specification -7.D Testing, galvanizing and mechanical routine tests in accordance section of BS. 3288 part 1 or such other standard as may be approved. The Employer from time to time, shall make further similar tests as may be required to ensure, that the quality of the product is being maintained throughout the Contract.
6.J
SCHEDULES The following schedules must be filled in by the Tenderer as applicable. - schedules No.2 A&B - schedules No.3 A&B - schedules No.4 A&B - schedules No.5 A&B - schedules No.6 A&B - schedules No.7 A&B 7
6.K
schedules No.8 A&B
OBLIGATIONS OF THE SUCCESSFUL TENDERER: The successful Tenderer should submit within fourteen days the technical drawings for the insulator sets and their fittings and the Conductor fittings to be approved by the Employer. No manufacturing, testing or shipping of materials is allowed before written approval of the Employer. Partial shipments can be approved.
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