IEC 60702-1 pdf download.Mineral insulated cables and their terminations with a rated voltage not exceeding 750 V
This standard applies to mineral insulated general wiring cables with copper or copper alloy sheath and copper conductors and with rated voltages of 500 V and 750 V. Provision is made for a corrosion-resistant extruded outer covering over the copper sheath, when required. This outer covering is not specified for the purpose of electrical insulation of the metal sheath. Requirements for terminations for use with these cables are specified in IEC 60702-2. The purpose of this standard is to specify mineral insulated cables that are safe and reliable when properly used, to state the manufacturing requirements and characteristics to achieve this, and to specify methods for checking conformity with those requirements.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60227-1:1993, Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 1: General requirements IEC 60228:1978, Conductors of insulated cables IEC 60331-21:1999, Tests for electric cables under fire conditions – Circuit integrity – Part 21: Procedures and requirements – Cables of rated voltage up to and including 0,6/1,0 kV IEC 60332-1:1993, Tests on electric cables under fire conditions – Part 1: Test on a single vertical insulated wire or cable IEC 60702-2:2002, Mineral insulated cables and their terminations with a rated voltage not exceeding 750 V – Part 2: Terminations IEC 60754-2:1991, Test on gases evolved during combustion of electric cables – Part 2: Determination of degree of acidity of gases evolved during the combustion of materials taken from electric cables by measuring pH and conductivity
For the purpose of this part of IEC 60702, the following definitions apply. 3.1 nominal value value by which a quantity is designated and which is often used in tables. Usually, in this standard, nominal values give rise to values to be checked by measurements, taking into account specified tolerances 3.2 routine tests (symbol R) tests made by the manufacturer on each manufactured length of cable to check that the whole of each length meets the specified requirements 3.3 sample tests (symbol S) tests made by the manufacturer on samples of completed cable, or components from a completed cable, at a planned frequency, so as to verify that the finished product meets the specified requirements 3.4 type tests (symbol T) tests made before supplying, on a general commercial basis, a type of cable covered by this standard, in order to demonstrate satisfactory performance characteristics to meet the intended application. These tests are such that, after they have been made, they need not be repeated unless changes are made in the cable material, design or manufacturing process which might change the performance characteristics
4 Voltage designations
The rated voltages of the cables considered in this standard are as follows. 4.1 500 V cable (light duty grade) For use where the voltage between conductors and sheath and between conductors does not exceed 500 V r.m.s. or 500 V d.c. 4.2 750 V cable (heavy duty grade) For use where the voltage between conductors and sheath and between conductors does not exceed 750 V r.m.s. or 750 V d.c.
Conductors shall consist of plain annealed copper and shall be of approximately circular cross-section. They shall comply with the requirements given in IEC 60228 for class 1 conductors. Compliance shall be checked by inspection and by measuring the resistance of each conductor of each complete coil of completed cable and measuring the length of the cable. The measured resistance shall be corrected to 20 °C and to a length of 1 km, in accordance with 11.2.
6.1 Composition The insulation shall consist of compressed powdered mineral or minerals which shall form a compact body. The electrical properties of the insulation shall be such that the completed cable shall meet the test requirements of this standard. 6.2 Thickness The nominal thickness of insulation between conductors and between each conductor and the sheath shall be as given in tables 7 and 10. When measured in accordance with 13.4, the minimum thickness shall be not less than 80 % of the nominal value minus 0,1 mm.