Specification Requirements for Cables Working in High Temperature Conditions (up to 2300 C)
1. General
The present requirements apply to flat cables with continuous copper leads, EPDM insulation, each lead shielded, armoured with galvanized strip, rated for 2 kV and for use at working temperature up to 2300 C. The requirements refer to the cables with cross-sections of 3x10, 3x13.3, 3x16 (mm2).
2. Cable Design
2.1 Cable leads shall be made of annealed electrical copper. The copper shall correspond to GOST 22483-77 or ASTMB 48/98 (DIN 17652, EN 1977) requirements.
2.2 Cable insulation shall be made of extruded vulcanite mixture based on EPDM resin with impermeable finish applied on copper lead. Insulation thickness at any cross-section shall not alternate more than 15%.
2.3 Lead alloy insulation shall be continuously applied on surface in seamless tube shape. The lead shield shall be steady and without holes. The sheath shall not have pores and foreign particulates, without cracks, cuts, dents and pits on the surface. The cable sheath thickness at any cross-section shall not alternate more than 15%.
2.4 Cable lead core shield shall be made according to Manufacturer’s technical requirements (TU).
2.5 Cable reinforcement shall be made with galvanized strip of 0.5 + 0.1 mm thickness.
3. Tests
3.1 Electrical and tests shall be performed at temperature of 20 + 50 С with AC voltage of
50 Hz.
• Cable cord resistance tests shall be performed on all cable conductors. Maximum permissible cable core resistance shall be as follows: for 10 mm2 cable – 1.83 ohm/km, 13.3 mm2 – 1.38 ohm/km, 16 mm2 -1.15 ohm/km.
• Cable insulation resistance tests shall be performed on all ready made cable conductors with DC voltage of 2500 V. Minimum permissible insulation resistance is 1400 МОhm/km.
• AC voltage electrical tests shall be performed on ready-made cables with 9 kV voltage for 10 mm2 cables, 10 kV – for cables with cross-section thickness more than 10 mm2, tests to be performed for 1 min avoiding cable faults.
• DC voltage electrical tests shall be performed on ready-made cables with 20 kV voltage for 10 mm2 cables, 25 kV – for cables with cross-section thickness more than 10 mm2, tests to be performed for 5 min avoiding cable faults. Cable core leakage current shall not exceed
25 microampere/km.
• Cable bending test. Cable bend minimum diameter shall be equal to 15-fold cable maximum diameter. Cable sample shall withstand bend on bending mandrel without opening cable amour lock.
• Cable shall withstand bends around rolls with diameters equal to 15-fold cable maximum diameter at temperatures not less than -400 С.
• Cable geometry shall conform to Manufacturer’s technical requirements (TU).
4. Delivery completeness
4.1. Complete shipment shall consist of the following:
• Cable,
• Cable drum,
• Certificate of Quality,
• Technical passport.
4.1 Cable nominal factory length
Permissible deviation in cable nominal factory length on the drum shall not exceed ± 1%. Delivery of two pieces of cable with factory length is allowed on one out of 5 drums from the delivered batch of cable, the smaller length shall not be less than 500 m and shall be located on the drum outer side. Cable length on the drum shall 2000 m or 2500 m long.
5. Marking
5.1. Cable drum shall have the following marking:
• Cable Manufacturer;
• Cable type and cross-section;
• Drum #.
5.2. Cable marking shall be made with Manufacturer’s trade mark and cable type on one of the cable cores.
5.4. Cable certificate shall be placed in a waterproof wrapping and fastened inside the drum. The certificate shall contain the following information:
• Cable type;
• Cable manufacture date;
• Cable length;
• Test results at the manufacturing plant;
• Cable warranty period;
• Gross weight, kg;
The certificate shall contain the Manufacturer’s QC seal.
6. Packing
6.1. Cable shall be delivered on steel drums. Cable outer surface shall be covered with solid wooden mats.
6.2 The lower end of the cable shall not be shorter than 2 m and be fixed at the inner side of the cable drum. Both cable ends shall be protected from contamination.
7. Warranty period
Cable operation warranty period shall be 18 months since the date of cable putting into service but not more than 24 months since the date of cable delivery to the Customer.
Free of charge cable replacement shall be made in the following cases:
• When cable non-conformance to Customer’s technical requirements is discovered at the acceptance test or at a special service center,
• At cable grading during the warranty period,
• Corrosion failure of galvanized steel strip,
• Decrease of insulating properties of cable core insulation materials (cable insulation current leak exceeds the accepted values),
• Geometry changes of cable core insulation (swelling, melting, deformation, conductor layer delaminating).
Regarding all above mentioned cases to verify the materials non-conformance the specialized service center should call a Manufacturer’s representative and work out a Cable Scrapping Report.
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