137-1: 2015 CEB SPECIFICATION. XLPE INSULATED SINGLE CORE UNDERGROUND CABLES OF 11 kv RATED VOLTAGE

Transcription

1 137-1: 2015 CEB SPECIFICATION XLPE INSULATED SINGLE CORE UNDERGROUND CABLES OF 11 kv RATED VOLTAGE CEYLON ELECTRICITY BOARD SRILANKA Telephone: Fax:

2 CONTENTS Page 1.0 Scope System Parameters Service Conditions Applicable Standards Basic Features Quality Assurance Additional Requirement Inspection & Testing Information to be furnished with the Offer Annex 9 Annex - A: Price Variation 10 Annex - B: Schedule of Technical Requirements and 12 Guaranteed Technical Particulars Annex C: Non-Compliance Schedule 14 2/14

3 SPECIFICATION FOR XLPE INSULATED SINGLE CORE UNDERGROUND CABLES OF 11 kv RATED VOLTAGE 1.0 SCOPE This specification covers the general requirements of the design, manufacture and test of Crosslinked Poly-ethylene (XLPE) Insulated single core underground cables for 11kV medium voltage underground systems. The cable conforming either to BS 6622, 6.35/11 (12) kv voltage designation or to IEC , 8.7/15 (17.5) kv voltage category may be offered and it is mandatory to provide Type Test Certificate done as per Section SYSTEM PARAMETERS (a) Nominal voltage (U) 11 kv (b) System highest voltage (Um) 12 kv (c) System frequency 50 Hz (d) Method of earthing Effectively earthed (e) System faults level 12.5 ka (f) Fault duration 1s 3.0 SERVICE CONDITIONS (a) Annual average ambient temperature 30 C (b) Maximum ambient temperature 40 C (c) Maximum relative humidity 90% (d) Environmental conditions Humid tropical climate with heavily polluted atmosphere (e) Operational altitude From M.S.L. to 1900 m above M.S.L. (f) Isokeruanic (Thunder days) level 100 days (g) Depth of laying 1.1 m 4.0 APPLICABLE STANDARDS The equipment and components supplied shall be in accordance with the latest editions of the s specified below and amendments thereof. (a) (b) BS 6622:2007 IEC : 2014 (c) BS EN60228:2005 IEC 60228:2004 (d) BS EN/IEC , 202,203,501:2012 (e) BS EN/IEC : 2007 BS 6622:2007. Electric cables. Armoured cables with thermosetting insulation for rated voltages from 3.8/6.6 kv to 19/33 kv. Requirements and test methods Power cables with extruded insulation and their accessories for rated voltages from 1 kv (Um = 1,2 kv) up to 30 kv (Um = 36 kv) Part 2: Cables for rated voltages from 6 kv (Um = 7,2 kv) up to 30 kv (Um = 36 kv) Conductors of insulated cables Electric and optical fiber cables - Test methods for non-metallic materials - Part 201: General tests - Measurement of insulation thickness, Part 202: General tests - Measurement of thickness of non-metallic sheath, Part 203: General tests - Measurement of overall dimensions, Part 501: Mechanical tests - Tests for determining the mechanical properties of insulating and sheathing compounds Electric cables - Tests on extruded over sheaths with a special protective function 3/14

4 5.0. BASIC FEATURES The technical requirements and the length of the XLPE Insulated single core underground cables shall be in accordance with the Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars and shall have the following characteristics. Depending on the choice of the bidder to provide cable conforming to either BS 6022 or IEC , provisions of the respective s shall be applicable. 5.1 Conductor The resistance of each conductor at 20ºC shall be in accordance with BS EN / IEC 60228, Circular Compacted Plain Annealed Copper Conductors of Class 2 and of size as stipulated in the Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars. 5.2 Conductor screen Conductor screen shall be of Extruded Semi-conducting Compound type. The extruded layer shall be continuous and shall cover the surface of the conductor completely. The Conductor Screen shall be applied in the same operation as the insulation and shall be fully bonded to the insulation. The volume resistivity of the conductor screen shall not exceed 500 Ω.m at 90 C when measured in accordance with Annex J of BS 6622 or Annex D of IEC as applicable. The thickness of the conductor screen shall be in accordance with BS 6622 or IEC s as applicable. 5.3 Insulation The insulation shall be XLPE and shall be applied by extrusion and cross-linked to form a compact and homogeneous layer in accordance with the Standards specified. The thickness of insulation shall conform to the BS 6622 or IEC s as applicable and compliance shall be checked by the tests given in the relevant British Standards or IEC Standard as applicable. 5.4 Insulation screen Insulation screen shall consist of non-metallic semi-conducting layer in combination with a metallic layer. Non-metallic semi-conducting layer shall be extruded in the same operation as the insulation. The extruded layer shall be continuous and shall cover the surface of the insulation completely. The insulation screen shall be cold strippable. The thickness of the insulation screen shall be in accordance with BS 6622 or IEC s as applicable. Note: The conductor screen, the insulation and the non-metallic insulation screen shall be extruded simultaneously in a single-head triple extrusion process. 5.5 Inner covering Inner covering shall be extruded or lapped materials suitable for the operating temperature of the cable and compatible with the insulating materials. Conditions of cable being buried direct in ground in sustained wet conditions should be considered. The thickness of the inner covering shall be in accordance with BS 6622 or IEC s as applicable. 5.6 Metallic screen The core shall be covered with a Screen of Copper in accordance with BS 6622 and IEC as applicable. The cross sectional area of the metallic screen shall be able to withstand the System Fault Level & Duration specified in the section Longitudinal water barrier Water barrier swelling tape or powder shall be provided to protect against longitudinal water penetration. 4/14

5 5.8 Metallic sheath A metallic sheath shall be provided if specified in Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars. Lead alloy sheath, which shall be free from defects, shall be provided over an inner covering, in accordance with IEC The inner covering shall be in accordance with clause 5.5 above. 5.9 Metallic Armour The armour shall be Aluminium alloy and shall consist of round wires. Metallic armour shall have an inner covering conforming to BS 6622 or IEC s as applicable. The nominal diameter of the armour wires shall be in accordance with BS 6622 or IEC s as applicable Oversheath The oversheath shall be of PVC-ST2 and shall be suitable for the maximum operating temperature in accordance with Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars. The colour of the oversheath shall be black or as specified in Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars. The mean value of the thickness shall not be less than the specified values in BS 6622 or IEC as applicable and compliance shall be checked by carrying out tests given in the relevant Standards. The oversheath shall withstand the DC voltage test in accordance with BS 6622 or IEC as applicable. This test shall be carried out on each delivery lengths Graphite Coating A coating of Graphite shall be applied over the oversheath to carry out D.C. Voltage Test. 6.0 QUALITY ASSURANCE The manufacturer shall possess ISO 9001:2008 Quality Assurance Certification valid throughout the delivery period of this bid, for the manufacture of XLPE Insulated Underground Cables for the plant where manufacturing is being done. The Bidder shall furnish a copy of the ISO certificate certified as true copy of the original by the manufacturer, along with the offer. 7.0 ADDITIONAL REQUIREMENTS 7.1 Manufacturing Experience The manufacturer shall have minimum of 10 years experience in manufacturing XLPE Insulated Underground Cables. In addition, minimum of five (5) years experience shall be in manufacturing for orders from outside the country of the manufacturer. The product offered has to be in same voltage range of offered item and shall have been used in service utilities over past 5 years. Manufacturer shall furnish a list of purchasers with year and quantity of the product offered with the offer to prove his manufacturing experience. 7.2 Packing The cables shall be supplied in non-returnable drums. Drums shall be made of steel and suitably protected against corrosion. A polythene lining shall be provided to prevent any damage to cable from the chemical used for preservation of timber battens. The drum shall be lagged with closely fitted battens to protect cable from damage. The ends of cables shall be sealed with heat shrinkable caps to prevent the ingress of moisture during transportation and storage. The length of cable per drum shall be 500 meters. The cable length per drum shall not vary more than ±2%. 5/14

6 7.3 Identification and Labeling The word "CEB", voltage rating as U0/U (Um), size of the cable, adopted, conductor size, year of manufacture, manufacturer s name or trade mark and travel length shall be embossed at intervals as stipulated in BS 6622 or IEC as applicable, on the outside of the oversheath. The embossing shall be weatherproof and abrasion proof. Each drum shall be labeled (with clear stencil) with the following; (a) (b) (c) (d) (e) (f) (g) (h) (i) PROPERTY OF CEYLON ELECTRICITY BOARD Bid No Serial No... Manufacturer's identification. Cable Type, Voltage Rating, Conductor Size and Number of Cores. Number and year of adopted. Net Weight & Gross Weight in kg. Length of cable in meter. Direction of rolling Year of Manufacture. 7.4 Technical Literature Adequate consideration shall have been given in the design of the cable and in the manufacturing process on the following. (a) Maximum design electrical stress shall be such that purity of raw materials, manufacturing conditions and ageing of cables has been taken into account. Maximum design stress shall not be more than 5kV/mm. (b) Purity of raw materials. (c) Close control of extrusion process to achieve smooth extruded surfaces, homogeneous extrudates and prevention of void formations. Documentary evidence on the above shall be provided along with the offer. 8.0 INSPECTION AND TESTING 8.1 Type Test Cable which undergo type test shall conform the requirements listed below irrespective of the relevant. Type tests performed on any other cable will not be accepted. (a) The type tested cable should have same insulation material, same form of semi-conductor screen, same manufacturing process but the conductor material can be copper, aluminium or other. (b) Type tested cable should be of equal or higher voltage designation. (c) Cross sectional area of the cable type tested shall not be smaller than the requested cable. However for cables of cross sectional area less than 630 mm 2, type test of cables of cross sectional area in the range 95 mm mm 2 inclusive will be accepted. (d) Type test done for three core cables will be accepted as type test for single core cables but type test for single core cable is acceptable only for the single core cable. Depending on the choice of the applicable s, the following Type Test Certificates conforming to the respective shall be furnished with offer For cable conforming to BS 6622 s (a) Conductor Screen Resistivity (b) Insulation Material (c) Insulation Screen Resistivity (d) Insulator Screen Cold Strippability (e) Semi-conducting Lapped Inner covering Resistance (f) Separation Sheath Material (g) Tests on Armour (h) Tests on Over Sheath Material 6/14

7 (i) Compatibility Test (j) Test under Fire Conditions (k) Partial Discharge Test (l) Bending Test (m) Tan δ in Relation to Voltage (n) Tan δ in Relation to Temperature (o) Heating Cycle Test (p) Impulse Voltage Test (q) Four-hour Voltage Test (r) Adherence of screens at short circuit temperature (s) Resistance of the cable at 20 C For cable conforming to IEC s (a) bending test (b) tan δ measurement (c) heating cycle test, followed by a partial discharge test (d) impulse test, followed by a voltage test (e) voltage test for 4 h (f) Resistivity of semi-conducting screens (g) discharge test (h) Measurement of thickness of insulation (i) Measurement of thickness of non-metallic sheaths (including extruded separation sheaths, but excluding inner coverings) (j) Tests for determining the mechanical properties of insulation before and after ageing (k) Tests for determining the mechanical properties of non-metallic sheaths before and after ageing (l) Additional ageing test on pieces of completed cables (m) Loss of mass test on PVC sheaths of type ST2 (n) Pressure test at high temperature on insulations and non-metallic sheaths (o) Test on PVC insulation and sheaths at low temperatures (p) Test for resistance of PVC insulation and sheaths to cracking (heat shock test) (q) Hot set test for EPR, HEPR and XLPE insulations and elastomeric sheaths (r) Water absorption test on insulation (s) Resistance of the cable at 20 C Type Test Certificates should clearly indicate the relevant, Items concerned, showing the manufacturers identity, type No. /catalogue No. and basic technical parameters. Test certificates referred to shall be from an accredited independent testing laboratory acceptable to the purchaser. Proof of accreditation by a national/ international authority shall be forwarded with the offer. Test reports shall be complete including all the pages as issued by the testing authority. Type test reports shall be in English language. Parts of test reports shall not be acceptable. 8.2 Routine Test Depending on the choice of the applicable s, the following Routine Test Certificates conforming to the respective shall be furnished for the observation of the Engineer appointed by the purchaser at the time of inspection For cable conforming to BS 6622 s (a) Spark Test on Oversheath (b) Conductor Resistance (c) Copper Wire Screen Resistance (d) Partial Discharged Test (e) Voltage Test on Complete Cable (f) Cable Marking (g) D.C. Voltage Test on Oversheath 7/14

8 8.2.2 For cable conforming to IEC s (a) Electrical resistance of conductors (b) Partial discharge test (c) Voltage test 8.3 Inspection The Successful bidder shall make necessary arrangements for inspection by an Engineer appointed by the CEB and also to carry out in his presence necessary Acceptance tests on equipment and material. CEB may waive off the inspection with the condition of witnessing the acceptance tests by an independent testing authority acceptable to CEB. In such a situation a notice of waive off will be issued in advance to the supplier. 8.4 Acceptance Test Depending on the choice of the applicable s, the following Sample/Acceptance Tests conforming to the respective shall be witnessed by the Engineer For cable conforming to BS 6622 s (a) Conductor Material and Construction (b) Conductor Screen Application (c) Insulation, Hot set Test (d) Insulation, Thickness (e) Insulation, Concentricity (f) Circularity of Cores (g) Insulation Tests on Screen (h) Metallic Screen, Application (i) Measurement of Amour Wires (j) Oversheath Thickness (k) Four-hour Voltage test For cable conforming to IEC s (a) conductor examination (b) check of dimensions (c) voltage test (d) hot set test 9.0 INFORMATION TO BE FURNISHED WITH THE OFFER The following shall be furnished with the offer. (a) A comprehensive catalogue on the types and sizes of XLPE Insulated Underground Cables offered. It shall necessarily include details about construction of the cable, mechanical properties and electrical properties of the cable (And material used). (b) Type Test Certificates in accordance with the clause 8.1. (c) Duly filled and signed Annex - B: Schedule of Technical Requirements and Guaranteed Technical Particulars. (d) Documents to prove manufacturer s experience in accordance with Clause 7.1. (e) Documentary evidence in accordance with clause 7.4. (f) ISO 9001:2008 Quality Assurance Certificate in accordance with clause 6. (g) Overall dimensional drawings. (h) A dimensional drawing of the drum. Failure to furnish the above information will result in the offer being rejected. 8/14

9 10.0 ANNEX Annex A: Price Variation Annex B: Schedule of Technical Requirements and Guaranteed Technical Particulars Annex C: Non-Compliance Schedule 9/14

10 Annex- A PRICE VARIATION The Bidders shall forward their offers on the basis of the Price Variation stipulated below. 1.0 BASIS OF THE OFFER (a) Bidders are required to make their offers on the basis of a Base Price (Bo) plus a Fixed Price Margin (FP). (b) The Base Price shall be the Cash Seller's Midday Official Average Price of Copper Grade A, Aluminium Alloy and Lead, at London Metal Exchange (LME) in US Dollars on the day of the closing of Bids or the previous working day if the day of closing of Bid is a non working day at the LME. (c) The Fixed Price Margin shall be quoted in the currency of choice of the Bidder in the case of foreign Bidders and in Sri Lanka Rupees in the case of Local Bidders. Accordingly FOB Price of foreign Bidders offering cables from outside the country and the exfactory price of Local Bidders shall be computed as; Where (* - If Applicable); [(B X MT x US) + (BA X MTA x US) + ( BL x MTL x US )* + ( FP x CC )] x TL B- Base Price which is the Cash seller's midday official average price of Copper Grade A in USD per Metric Ton at the LME on the fixed date (Clause (b) above). BA- Base Price which is the Cash seller's midday official average price of Aluminium Alloy in USD per Metric Ton at the LME on the fixed date (Clause (b) above). BL - Base Price which is the Cash seller's midday official average price of Lead in USD per Metric Ton at the LME on the fixed date (Clause (b) above). FP- Fixed Price Margin per kilometre of Cable in the Currency of choice. MTA- Quantity of Aluminium Alloy required to manufacture one kilometre of cable in Metric Ton. MT - Quantity of Copper Grade A required to manufacture one kilometre of cable in Metric Ton. MTL- Quantity of Lead required to manufacture one kilometre of cable in Metric Ton, as applicable TL- Total Length of Cable as applicable CC - Conversion rate from the currency of choice to Sri Lankan Rupees prevailing on the Date of Bid opening. US - Conversion rate from the US Dollars to Sri Lankan Rupees prevailing on the date of Bid opening. 2.0 AWARD PRICE (d) The FOB Award Price for Bidders offering Cables from outside the Country and the Ex-factory Award Price of Local Bidders offering Cables shall be computed as; [(B1 X MT x US) + (B1A X MTA x US) + ( B1L x MTL x US )* + ( FP x CC )] x TL Where; B1 - Base Price which is the Cash seller's midday official average price of Copper Grade A in USD per Metric Ton at the first working day immediately after the day of award B1A - Base Price which is the Cash seller's midday official average price of Aluminium Alloy in USD per Metric Ton at the first working day immediately after the day of award B1L- Base Price which is the Cash seller's midday official average price of Lead, in USD per Metric Ton at the first working day immediately after the day of award 10/14

11 (e) Intimation of the award will be faxed/telexed to the successful Bidder and or his agent in Sri Lanka. 3.0 CONVERSION OF CURRENCY (f) For the purpose of the evaluation the Price B in US Dollars and the Fixed Price Margin (FP) in the currency of choice of the Bidder will be converted to Sri Lanka Rupees at the official Middle Exchange Rate of the Central Bank of Sri Lanka prevailing on the day of opening of Bids. (g) The payment for the supply of Cables outside the country will be made to the Supplier at the contract price in the currency quoted for the Fixed Price Margin (FP). The base price B1 in US Dollars will be converted to the currency of the FP at the exchange rates indicated in the bulletin of the LME applicable on the first working day immediately after the date of the award of the offer; where such exchange rate is not available for the currency of the FP in the Bulletin the official middle exchange rate at the Central Bank of Sri Lanka shall be applicable. (h) The payment for supply of Cables from within the Country by Local Suppliers will be made in Sri Lanka Rupees. The Base Prices, B & B1 in US Dollars will be converted to Sri Lanka Rupees at the official Middle Exchange rate at the Central Bank of Sri Lanka prevailing on the date of the letter of award. 4.0 VARIATION FIGURES The Bidders shall furnish Fixed Price Margin and the weight of Copper required to manufacture one kilometre of Cables of each type and size as indicated below. Failure to furnish these particulars will result in the offer being rejected. (i) Description of the UG Cable offered Voltage Rating U(Um) (kv) - Material of Conductor - Area of the Conductor (mm2) - (j) Fixed Price Margin for manufacture of one Kilometre of Cable in the currency of choice (FP) - (k) Weight of Copper Grade A required for the Manufacture of one Kilometre of Cable (kg/km) - (l) Weight of Aluminium Alloy required for the manufacture of one Kilometre of Cable as - applicable (kg/km) (m) Weight of Lead required for the manufacture of one Kilometre of Cable as applicable (kg/km) -.. Signature of the Manufacturer and seal.. Date I/We certify that the above data are true and correct Signature of the Bidder and seal.. Date 11/14

12 12/14 CEB SPECIFICATION 137-1: 2015 Annex- B SCHEDULE OF TECHNICAL REQUIREMENTS AND GURANTEED TECHNICAL PARTICULARS (CEB Requirements shall be filled by the procurement entity and information of the offer shall be filled by the manufacturer) CEB Requirement Offered 1. Name of the Manufacturer 2. Country of Origin 3. Length of the cable m 4. Nominal cross sectional area mm 5. No. of cores 1 6. Lead Metallic Sheath Yes/No 7. Colour of the Sheath 8. Rated Voltage category 11 kv 9. System Highest Voltage 12 kv 10. Maximum Fault Current and duration 12.5 ka, 1s 11. Basic Insulation Level 95 ka 12. Maximum Nominal Operating Temperature 90 C 13. Depth of laying 1.1m 14. Maximum Design Stress 5 kv/mm 15. Applicable Standards 16. Conductor Particulars (a) Diametermm (b) Number of strands. (c) Diameter of strands. (d) Material (e) Shape (f) Type Nos. mm BS 6622/IEC as applicable Annealed Copper Round I. Solid / Stranded Stranded II. Compact / Non compact Compacted 17. Conductor Screen Particulars (a) Material Copper (b) Thickness mm (c) Method of Application Extruded (d) Whether applied in the same operation as insulation As per clause Insulation Particulars (a) Material XLPE (b) Extrusion process Triple I. Minimum average mm II. Minimum at a point mm 19. Insulation Screen Particulars non-metallic semiconducting (a) Type I. Semi-conducting layer Extruded II. Metallic No III. Strippability Cold (b) Material Extruded Semiconducting Compound (c) Maximum Electrical Stress 5 kv.mm 20. Inner covering As per clause Metallic Screen As Per Clause Longitudinal water blocking As per clause 5.7 form of water blocking material 23. Metallic 1 armour As per clause 5.9 (a) Material Aluminium Alloy

13 24. Oversheath (b) Diameter of a wire (a) Type/Material mm CEB SPECIFICATION 137-1: 2015 PVC-ST2 (b) Thickness I. Nominal mm II. Min. at a point mm (c) Whether Graphite layer provided As per clause 5.11 (d) Whether DC test on oversheath carried out 25. Overall diameter of cable mm 26. Approximate weight of cable kg/ km 27. Minimum bending radius mm 28. Whether the cable ends are sealed before shipping As per clause Indicate the details of marking provided on the over sheath. (a) Cable Designation (b) 30. Current Rating (a) (b) Identification of manufacturer Laid direct Laid in ducts (c) Laid in air (d) Whether the maximum symmetrical short circuit current rating Yes curves for 0.2 to 3 Sec. duration Furnished 31. Conditions of laying where the above rating are valid. (a) Standard depth of laying 1.1 m (b) Ambient air temperature 30 C 32. (a) Maximum conductor DC resistance at 20 C Ω/km (b) Maximum conductor reactance at 50 Hz (c) Maximum conductor capacitance at 50Hz (d) Coefficient of Thermal variations of the Electrical parameters 33. Maximum allowable conductor temperature at and duration (a) Full Load conditions/ Duration (b) Short Circuit conditions/ Duration (c) Over load conditions/ Duration (d) Allowable maximum overloading in determining the above Ω/km μ F/km %/A 34. Drum Particulars (a) Material of the drum Steel (b) Dimensions. mm x mm (c) Weight kg (d) Standard cable length 500m (e) Weight of length with drum kg 35. Whether 3 a certified copy of ISO 9001:2008 furnished with the offer? As per clause Whether the entire Type Test Certificates in accordance with clause 8.1 As per clause 8.1 furnished with the offer?.. Signature of the Manufacturer and seal.. Date I/We certify that the above data are true and correct Signature of the Bidder and seal 13/14.. Date

14 Annex C Non-Compliance Schedule On this schedule the bidder shall provide a list of non-compliances with this specification, documenting the effects that such non-compliance is likely to have on the equipment life and operating characteristics. Each non-compliance shall be referred to the relevant specification clause. Clause No. Non-Compliance. Signature of the Manufacturer. Date I/We certify that the above data are true and correct Signature of the Bidder and seal.. Date 14/14