SPECIFICATION FOR UNARMOURED CONTROL CABLES

Transcription

1 PAGE : 1 of SCOPE SPECIFICATION FOR UNARMOURED CONTROL CABLES Manufacture, testing, delivery and guarantee of various sizes of annealed bare copper conductor, HR PVC insulated and FRLS PVC sheathed unarmored, overall shielded 500 V grade instrumentation cable generally conforming to BS-5308-Part-2 for use in Nuclear Power Plant. 2.0 CONTENTS Requirements of this specification are presented under the following section headings Description Clause Applicable specifications and drawings 3 Materials and workmanship 4 General Function and description 5 Design requirements 6 Inspection, test and reports 7 Shop tests 8 Packing and shipment 9 Information required with the bid 10 Colour & Numbering Scheme for the cores and sheaths Annexure-A Technical details to be supplied with the technical bid Annexure-B Delivery schedule and price details Annexure-C Quality Assurance Plan Annexure-D 3.0 APPLICABLE SPECIFICATIONS AND DRAWINGS 3.1 BS-5308 Part 2: Instrumentation Cables. Specification for PVC insulated cables. 3.2 ASTM-D-2843: Standard Test method for density of smoke from the burning or decomposition of plastics. Or 3.3 IS : Measurement of smoke density of electric cables under fire conditions (supplier to indicate the acceptance criteria which is equivalent to ASTM-D-2843 vide clause no.6.5 of specification).

2 PAGE : 2 of ASTM-D-2863: Standard method for measuring the minimum oxygen concentration to support candle like combustion of plastic (oxygen index and temperature index). Or 3.5 IS : Methods of tests for cables : Oxygen Index Test. 3.6 IEC : Determination of the amount of halogen and gas evolved during the combustion of polymertic materials taken from cables. 3.7 IS : Determination of the amount of halogen acid gas evolved during the combustion of polymeric materials taken from cables. Or 3.8 Swedish Svensk Standard (Class F3) : Swedish Chimney Flame Test. Or 3.9 IS : Flame Retardant Test BS-6746 (or IS-5831) : Specification for PVC insulation and sheath of electric cables BS-6360 (or IS-8130): Specification for conductors for insulated electric cables and flexible cords IS : Methods of tests for cables. 4.0 MATERIALS AND WORKMANSHIP 4.1 The materials and processes for the components of cables and their assembly shall be chosen as specified herein. Use of any substitute materials shall be suitably qualified in terms of its electrical, mechanical and physical properties and the details shall be submitted by supplier for purchaser s approval. All the materials and processes which are not specified herein shall be chosen so as to enable the purchased product to meet the performance requirements of this specification. The construction of cable shall in general conform to BS Workmanship Workmanship shall be of high industrial quality to ensure the product to be uniform in quality and free from all defects and deformities so as to perform its required function in the specified environment as mentioned in this specification over an expected plant life of 40 years.

3 PAGE : 3 of GENERAL FUNCTIONS AND SPECIFICATIONS 5.1 The cables shall be suitable for continuous and reliable operation at maximum conductor temperature of 85 o C and voltage upto and including 300V for core to earth and 500V for core to core. 5.2 Environment Conditions (a) Ambient Temperature : 45 o C Max (b) Relative Humidity : 95% Max 6.0 Design Requirements All materials used should be first class and of standard conforming to the requirements of this specification. 6.1 Conductor Conductors shall be of annealed bare solid circular copper conductor in accordance with BS-6360 or IS-8130 for Type I overall shielded cables. Joints of any kind in the conductor are not allowed. 6.2 Insulation Insulation shall be 85 o C, Heat resisting PVC (Type 5 of standard BS-6746 or Type C of IS-5831) and shall be meeting physical requirement of this standard. Grade of insulation shall be 500V. No joints of any kind in the insulation are permitted. Insulation shall be applied by extrusion process. The colour of insulation shall be as per Annexure-A of this specification for each type of cable. 6.3 Core Identification Overall shielded cables Colour code cores of cable shall be color codes as per Annexure-A of this specification.

4 PAGE : 4 of Shielding Over the assembled pairs shall be applied non-metallic binder such as polyester. In intimate contact with binder shall be applied polyester backed aluminium tape with minimum 25% overlap such that polyester surface comes to the top. The thickness of aluminium shall be mm. a tinned solid copper drain wire of 0.75 sq.mm shall run in contact with and below the aluminum tape through out the length of the cable for grounding purpose. 6.5 Sheath Sheath material shall be PVC type 5 or Type ST2 meeting physical requirements as specified in BS-6746 or is-5831 respectively. The oxygen index shall not be less than 29 and temperature index shall not be less than 250 o C as per ASTIM-D or IS and smoke density shall not be more than 60% when tested as per ASTM-D Smoke density test may be conducted as per IS supplier to indicate the acceptance criteria which is equivalent to 60% smoke density rating as per ASTIM-D HCL emission shall not exceed 20% when tested as per IEC or IS it should be possible to strip the jacket without damaging the insulation. Jacket shall be of Black colour. 6.6 Construction Details of cables Type I overall shielded cables Sq.mm SINGLE PAIR overall shielded cable Each conductor shall be 1.5 sq.mm annealed bare solid copper conductor insulated with HR PVC of 0.6 mm (nominal) ± 10% wall thickness by extrusion process. Such two cores shall be twisted together (min. 12 lays per meter, Then it is covered with PVC sheath of wall thickness of 0.8 mm (nom) ± 20% by pressure extrusion process. A rip cord shall be provided below the sheath for easy stripping of the sheath. Lay of pairs shall be staggered. Overall diameter shall not exceed 9 mm sq.mm 3 pair overall shielded cable Same as but 3 pairs, sheath thickness of 1.2 mm (nominal) ± 20% and overall diameter shall not exceed 14 mm.

5 6.7 Cable Identification PAGE : 5 of 9 Durable identification marking shall be provided with following details throughout the length of cable at a span of 1 meter for all types of cables SINGLE PAIR and Three pair shielded cables. (a) Name of manufacturer (b) Year of manufacture (c) FRLS PVC cable (d) Voltage grade : 500 Vrms 6.8 Coil lengths The cables of each type shall be supplied in coil lengths of 500 m ± 10% coil lengths of 100 m to 449 m are considered as non-standard lengths. Non standard lengths of only 10% of ordered quantity are acceptable. Lengths less than 100 m are not acceptable. 7.0 Inspection Tests & Reports The supplier shall be responsible for and shall perform all the tests and inspection as mentioned in this specification any other tests which may be necessary to assess the required performance of the cable. The characteristic and performance of the cable shall conform to this specification on completion of tests. The purchaser or his representative shall have right to access to manufacture s premises at all reasonable times for following up the manufacturing activities and validation of testing procedures to ensure that quality of performance meets this specification. The purchaser shall have right to conduct at his own expenses any additional inspection and testing deemed necessary by him. Quality Surveillance relating to all aspects of manufacture shall be carried out by the purchaser. The supplier shall provide all the testing and inspection services and facilities satisfactorily as required. Inspection shall be carried out in satisfactory manner and shall be subjected to approval by the purchaser. Quality Assurance Plan (QAP) has been enclosed with the specification. The supplier shall prepare an inspection plan based on enclosed QAP and submit to purchaser for approval.

6 PAGE : 6 of 9 Five copies of test reports and certificates of compliance stating the materials is in accordance with the requirement specified in he specification shall be furnished by the supplier. 8.0 Shop Tests 8.1 Type Tests Applicable standard Annealing test for copper BS-6360/IS Conductor Resistance Test BS-6360/IS Measurement of diameter of conductor BS Measurement of thickness of insulation and sheaths BS Tensile test on Insulation and Sheaths BS-6746/IS Elongation test on insulation and sheath BS-6746/IS Hot deformation test on insulation and sheath BS-6746/IS Heat shock test on insulation and sheath BS-6746/IS Accelerated ageing test on insulation and sheath BS-6746/IS Loss of mass test on sheaths BS-6746/IS Clod bend test on insulation and sheath BS-6746/IS Swedish chimney flame test (Swedish Svensk Standard) SS (F-3)/ IS Shrinkage test on insulation and sheath IS Thermal stability test on insulation and sheath IS Voltage Test at 1.5 KV BS Insulation Resistance Test BS-6746/IS-5831

7 PAGE : 7 of Measurement of overall diameter Test for continuity of tin coating BS Oxygen index test and temperature index test on sheath ASTIM-D-2863/ IS HCL emission test on sheath IEC-754-1/ IS Smoke density rating test on sheath ASTM-D-2843/IS (Supplier to indicate the acceptance criteria which is equivalent to ASTM-D-2843 as per clause no.6.5 of the spec. if test is done as per IS ) Measurement of mutual capacitance and capacitance between any core or screen BS Acceptance Tests The following acceptance tests shall be carried out on samples taken from the lot of each type of cable. The total number of drums of each type of cable shall be treated as a lot size. The same size for the acceptance test shall be as per Appendix-A of IS-5608-Part-I Elongation test for copper BS-6360/IS Conductor Resistance Test BS-6360/IS Measurement of thickness of insulation and sheath BS Insulation Resistance Test BS-6746/IS Voltage Test BS Oxygen Index Test and Temperature Index tests On sheath ASTM-D-2863/ IS

8 PAGE : 8 of Smoke Density rating test on sheath ASTM-D-2843/IS (Supplier to indicate the acceptance criteria which is equivalent to ASTM-D-2843 as per clause no.6.5 of the spec. if test is done as per IS ) HCL Emission Test on Sheath IEC-754-1/IS Measurement of mutual capacitance and Capacitance between any core or screen BS Swedish Chimney Flame Test SS (F3) / IS Measurement of overall diameter Routine Tests Conductor Resistance Test BS-6360 / IS Insulation Resistance Test BS-6746/IS Voltage Test BS Packing and Shipment The cables shall be so packed as not to suffer deterioration, damage or breakage during shipment. The ends of the cables shall be sealed to prevent ingress of moisture. Packing should be such that the ingress of moisture, dirt and other foreign material can be avoided. Packing method shall be adequate to withstand a period in transit for more than two months and storage at site under a tropical climate for minimum period of one year without suffering any damage or deterioration. Each package shall be properly labeled to indicate the type and quantity of material it contains, purchase order number, dimensions, weight, and any other necessary data to identify the equipment and relate it to the contract. Contractor shall not ship the material without the prior approval of the purchaser or his authorized representative and subsequent instruction to do so.

9 PAGE : 9 of 9 Complete instructions relation to shipping and documentation will be furnished with the P.O. 1.0 COLOUR AND NUMBERING SCHEME OF THE CABLES Annexure-A 1.1 Type I overall shielded cables SINGLE PAIR THREE PAIR White -1 White-1 Blue -1 Blue -1 Orange-2 Green-2 Brown-3 Grey-3 Colour code for inner and outer sheath For all the cables inner and outer sheath colour shall be BLACK.