SPECIFICATION FOR FRLS POWER CABLES

Transcription

1 SPECIFICATION FOR FRLS POWER CABLES 1.0 SCOPE This specification cover the technical requirements of design, manufacture, testing and delivery to site of Power Cables of 1100V grade with FRLS PVC Sheathed, HR PVC insulated, Aluminium conductors for use in Madras Atomic Power Station, Kalpakkam, Tamil Nadu. 2.0 CODES AND STANDARDS Details are as given in Annexure-I 3.0 GENERAL DESIGN REQUIREMENTS a) Cables shall be designed and manufactured so that damage will not result from transportation, installation and operation under all the climatic and operating conditions to which they may be subjected. b) Cables shall be suitable for laying conduits, vertical installation, ducts, trenches and trays or for direct burial in ground in both wet and dry locations. c) All materials used shall be new and shall conform to this specification and relevant Indian Standards. d) The cables shall be suitable for continuous and reliable service at maximum voltage of 1100 V and at a max. conductor temp of 85 degree. 4.0 SPECIFICATION OF CABLES 4.1 The conductors shall be annealed, stranded high conductivity Aluminium/Copper high grade, HRPVC insulated, laid up extruded PVC (FRLS) inner sheathed, single galvanized round steel/aluminium wire armoured and overall jacketed with PVC (FRLS) 4.2 FRLS PVC PROPERTIES FRLS PVC shall be following properties / Characteristics. a) The Oxygen index of cables shall be more than 30 % at 27 0 C C When tested in accordance with ASTM-D b) Temperature index shall be more than C c) Cables shall have smoke density of less than 50 % Max. d) The Hydrochloric acid evolution shall be less than 17.5 % e) Flammability test on finished cable. The bidder shall furnish the relationship between oxygen index and the temperature if any along with necessary relevant data about these properties with the offer.

2 4.3 CORE IDENTIFICATION For 1 C cable : Red, for 2 C cables: Red and Black, for 3 C cable : Red, Yellow, Blue, for 4 C cables; Red, Yellow, Blue and Black.For cables more than 4 C, as per NEMA-WC-5 meant for thermoplastic insulated wires and cables for transmission and distribution of electrical energy. 4.4 CABLE SIZE AND LENGTHS The size and quantity of cables are as given in Annexure CONSTRUCTIONAL FEATURES 5.1 CONDUCTOR The conductors shall be of H 2 or H 4 grade Aluminium as per latest IS:8130 and shall be circular shaped. The conductor strands shall be solid and free from any inequalities or defects. 5.2 INSULATION Insulation shall be of extruded HR PVC material conforming to the latest IS SHEATH a) INNER SHEATH The inner sheath of cable shall be FRLS ST-2 types as per IS-5831 and this should be extruded over the laid up core. The surface of the sheath shall be uniform, continuous and free from defects. Inner sheath shall be as per table-3 of latest edition of IS-1554 Part-1. Filler material if used shall be non-hygroscopic, thermoplastic material and over this PVC/Plastic/millar type shall be provided for binding the core. Thermoplastic material shall be softer than outer sheath. b) OUTER SHEATH The outer sheath of the cable shall be of FRLS PVC-ST-2 type and should be extruded uniformly over the armouring of cable. Sheath shall confirm to IS-1554 Part-I and for dimensional requirement IS Outer Sheath shall be black in colour. All markings i.e. Nuclear Power Corporation, year of manufacture, voltage grade shall be embossed on the outer sheath. Sequential no. marking shall be given in printed form at every meter of the cable.

3 5.4 ARMOUR The Armour used shall be galvanized round steel wire and shall conform the latest IS For single core Cable aluminum wire shall be used. 6.0 INSPECTION AND TESTING QA plan of suppliers shall be approved by purchaser. Manufacturing and quality control of procedure, record shall be properly maintained which shall be offered for review to purchaser s representative STAGE INSPECTION Supplier should carry out stage wise inspection as per approved quality control plan and the records shall be shown to NPC, QS Engineer for review in case desired by QS Engineer. 8.0 FINAL TESTS The supplier shall conduct the final tests in the presence of purchaser s representative. Details of all the test are given below: Acceptance Test. a. Tensile Test (IS:8130) (For Aluminium) b. Wrapping Test (IS:8130) (For Aluminium) c. Conductor Resistance Test (IS :8130) d. Test for armour wires (IS:3975) e. Test for thickness of insulation and sheath (IS:5381) f. Physical test for insulation and outer sheath (IS: 5831) g. Insulation Resistance Test (IS : 5831) h. High voltage Test (Water Immersion Test) (IS:1554) i. Critical Oxygen Index Test (ASTM-D 2863) j. Temperature Index Test (ASTM-D-2863) k. Acid Gas Generation Test (To determine percentage of hydrochloric acid released from the PVC jacket over the cable) (IEC-754-1) l. Smoke generation test (ASTM-D-2843/77) m. Flammablity test for finished cables-iec-332. n. Flammability Test Class F-III Swedish SS Information and data based on the previous test conducted on the similar type of cables of tests I to n shall be submitted with the offer

4 ROUTINE TEST a. Conductor Resistance Test (IS-8130) b. High Voltage Test (IS-1554) c. Measurement of insulation resistance on the complete supplied length of cable in all the drums. 9.0 CABLE SUPPLY LENGTH & DRUM 9.1 DRUM LENGTH Cables shall be supplied in specified non-returnable wooden drums. The bidder shall offer the cables in drum lengths specified in Annexure-2 with allowable tolerance of +5%-0%. The bidder shall indicate in the offer the maximum length of each size of cable that can be furnished in one drum. 9.2 CABLE DRUMS The drums shall be of heavy construction made up of good quality wood. Ferrous parts used shall be treated with suitable rust preventive finish or coating to avoid rusting during transit or storage. The drums shall be suitable for outdoor storage for long periods without deterioration. 9.3 CABLES LENGTHS Cable lengths as specified in this specification are approximate. Actual requirements will be confirmed to the successful bidder at the time of placing the order PACKING AND TRANSPORT The cable shall be placed on drums in such a manner that it will be protected from damage during transit. Each end of the cable shall be firmly and properly secured to the drum. The end of each length shall be sealed before shipment. The drums shall be secured firmly in position so that they will not shift during transit. All details shall be marked legibly to each end of the drum indicating the purchaser s order number, length of cable, size of conductor, number or cores, type of cables and voltage for which it is suitable, reference I.S., manufacturer s name, weight and the year of manufacture. A tag containing the same information shall be attached to the leading end of the cable. An arrow and suitable accompanying wording shall be marked on one end of the drum indicating the direction in which it should be rolled.

5 The number of each drum shall be either branded at the end of the drum or stamped on metal discs to an end of the drum DOCUMENTATION 2 copies of documentation in bound volume shall be supplied prior to the transportation of the cables. The volume shall include amongst others, the following particulars: a) General Information b) Principal Technical Data c) Description of Insulation and Sheathing d) Installation and Termination instructions e) Test Reports/Certificates f) P.O. Copy g) Shipping Release 12.0 DELIVERY SCHEDULE The cable shall be supplied within 10 weeks from the date of placement of the purchase order The bidder shall submit technical data as per annexure-3 of this tender specification, without which tender shall not be considered for evaluation.

6 CODES AND STANDARS ANNEXURE-I 1. IS-1554 Part-I PVC insulated cable for working voltage up to and including 1100 V 2. IS-3961 Part-II & V Recommended current ratings for cables 3. IS-3975 Mild steel wires and tapes for armouring of cables 4. IS-4826 Hot dipped galvanized coatings on round steel wires 5. IS-5831 PVC insulation and sheath of electric cables 6. IS-6380 Specification for Elastomeric insulation and sheathing of electrical cables. 7. IS-8130 Conductors for insulated electric cables and flexible chords 8. IS Drum for electric cables 9. IS Methods of test for cables 10. IEC-287 Calculation of the continuous current rating of cables (100 % load factor). 11. IEC & 3 Tests of Electric cables under fire conditions 12. IEC-331 Fire resistance characteristics of electrical cables 13. IEC Tests on gases evolved during combustion of electrical cables. 14. ASTM-D-2843 Test method of density of smoke from the burning or decomposition of plastics 15. ASTM-D-2863 Test method for measuring the minimum oxygen Concentration to support candle like combustion of plastics (oxygen Index) 16. IEEE: 383 Standard for type test of Class-1E Electric cables, field splices and connections for Nuclear power generating stations. 17. SS Swedish standard for cables testing of flame propagation characteristics 18. IEC-189 Low frequency cables and wires with PVC insulation and PVC sheath. Part-I General test and measuring methods. 19. NEWMA-WC-5 Thermoplastic insulated wires and distribution of electrical energy.

7 Annexure-II S.No Cable Size Quantity in Meters 1. 3c x 6 sq mm Aluminium conductor cable 2. 3c x 10 sq mm Aluminium conductor cable Drum Lengths in Remarks Meters ) Drum length tolerance for all the sizes shall be only +ve side 2) Upper limit at +ve tolerance shall be 5 %

8 Annexure-III The following data to be furnished by the TENDERER Alongwith the Tender for each cable. 1. Name of the Manufacturer 2. Voltage grade 3. No. of Cores 4. Armoured / Unarmoured 5. Whether suitable for unearthed / earthed system 6. Maximum permissible voltage variation 7. Maximum permissible frequency variation 8. Whether cable will carry ISI mark 9. Whether the list of supplies of similar cables enclosed 10. Continuous current rating with single cable laid in air in an ambient temperature of 45 0 C and max. Conductor temperature 70 0 C 11. Continuous current rating with single cable laid directly in ground temperature of 35 0 C and max. Conductor temperature 70 0 C 12. De rating factors for the following shall be indicated: Variation in ambient air temperature (for cables laid in air) from 35 0 C to 50 0 C in step of 5 0 C. Variation in ambient air temperature (for cables laid directly in ground from 15 0 C to 50 0 C in step of 5 0 C 13. Grouping : Furnish chart showing de rating factors for different spacing of cables connecting multi core cables installed in horizontal formation in single row as well as in different tiers under the following methods of laying Cables lain in formed concrete cable trenches with removable covers. Cables laid in cable trays side by side without spacing in groups both for vertical and horizontal runs. Cable laid in ground. Cables laid in pipes or unventilated ducts duty. 14. Short Circuit capacity Short Circuit current for different duration of short circuit from 0.1 to 1 sec. (Preferably attach) for curves that apply to various cables covered by this specification Amp/sec. Conductor temperature allowed for short circuit duty ( 0 C) 15. Loss tangent at normal frequency. 16. Dielectric constant at normal frequency. 17. Conductor. Material and its hardness No. of stands. Diameter of stands.

9 Overall diameter of conductor 18. Normal cross section area 19. Temperature coefficient of resistance at 20 0 C / 0 C 20. Strands tinned ( Yes / No). 21. No. of twists / unit length 22. Insulation Composition of Insulation Thickness of Insulation Tolerance of the Insulation Colour Scheme for identification of cores Electrical properties at 20 0 C 23. Conductor resistance to loop. 24. Minimum insulation resistance 25. High voltage test Conductor to Conductor Conductor to Shield Mutual capacitance 26. Power frequency withstand voltage Dry Wet 27. Conductor resistance test. 28. High voltage test. 29. Temperature rise tests on power circuit 30. Short time current tests on power circuits 31. Annealing Tests 32. Test for insulation and sheath 33. Test for inner and outer sheaths of cables 34. Test for acid gas generation 35. Inner Sheath Material Whether extruded Calculated diameter over stranded cores Thickness of inner sheaths Tolerance on thickness of sheath 36. Outer Sheath Material Calculated diameter over stranded cores Tolerances of thickness of sheath Colour of Sheath. 37. FRLS PVC inner and outer Sheath properties Minimum critical oxygen index value at room temperature of 35 0 C Minimum temperature index ( 0 C)

10 Maximum Halogen content by weight (%$) Maximum smoke density rating (%) Density of FRLS sheath material (g/cm 3 ) Tensile strength of sheath material (N/mm 2 ) Elongation of break of sheath material (%) Volume resistivity (Ohm/cm) Dielectric strength at a temperature of 20 0 C (kv/mm) Cold bend temp. ( 0 C) Hot pressure deformation at a temperature of C (%) Typical aging behaviour of FRLS PVC sheath material. Temp ( 0 C) Duration (Days) Oxygen Index % of Original Property Tensile Elongation Strength at break Oxygen Index 38. Armour a) Type of Armour b) Nominal diameter of cable over inner sheath (min.) c) Nominal dimensions of round wire d) Tolerance on round wire +mm e) D.C resistance of galvanized steel wire /Alu. Wire at 20 0 C ohm/km 39. Finished cables Overall diameter of the cable (mm) Weight per 1000 meter cable (Kg) Insulation resistance at 20 0 C per 1000 meters Conductor resistance at 20 0 C per 1000 meters Recommended minimum installation radius (mm) Safe pulling force when pulled by pulling eye. Will the cable offered against this specification pass the flammability test as per IEC-332 SS Cable drums (wood) a) Material used b) The dimensions and weights of cable drum c) Relevant IS reference d) Drums assignments e) Maximum length per drum for each size of cable (m) 41. Cables are tropicalised and rodent resistant