IEC 61156-2:2010 pdf – Multicore and symmetrical pairlquad cables for digital communications -Part 2: Symmetrical pairlquad cables with transmission characteristics up to100 MHz – Horizontal floor wiring – Sectional specification.
3 Characteristics and requirements
3.1 General remarks
This clause lists the characteristics and minimum requirements of a cable complying with this specification
A detail specification may be prepared to identify a specific product and its performance capabilities (see Clause 4).
Test methods shall be In accordance with Clause 3 of IEC 61156-1:2002.
3.2 ElectrIcal characteristics
The tests shall be carried out on a cable length of not less than 100 m, unless otherwise specified.
3.2.1 Conductor resistance
The conductor resistance Is not specified but shall be indicated in the relevant detail specification.
3.2.2 R.slstanc. unbalance
The conductor resistance unbalance within an element shall not exceed 3 %.
3.2.3 Dielectric strength
There shall be no failures when a test is performed on conductor/conductor and, whore screen(s) are present, a conductor/screen with 1.0 kV d.c. for 1 mm or. alternately, with 2,5kV dc for 2 s. An a.c. voltage may be used. The a.c. voltage levels in these cases shall be 0.7 kV a.c. for I mm or, alternately. 1,7kV a.c. for 2s.
3.2.4 InsulatIon resistance
The test shall be performed both on
— conductorlconductor;
— conductoriscreen, screen/screen when present.
The minimum insulation resistance value shall not be less than 150 ML)-km, at or corrected to
20 C.
3.2.5 Mutual capacitance
Mutual capacitance is not specified but may be indicated in the relevant detail specification.
3.2.6 Capacitance unbalance
The maximum capacitance unbalance pair to ground shall not exceed 1 700 pF/500 m at a frequency of 800 Hz or 1 kHz.
3.2.7 Transfer impedance
For screened cables, the value shall not exceed:
– 50 mUm, at 1 MHz;
— 100 mU/rn at 10 MHz:
— 300 mU/rn at 30 MHz:
– 1 000 mUim at 100 MHz.
3.3 Transmission characteristics
The test shall be carried out on a cable length of 100 m.
NOTE Where approxiate. transmission ctarac1er.stics are specired by categories whic1 depend on application and system requirements.
The masimum referenced frequencies for cables covered by Ifles specification are;
— 16 MHz for category 3:
— 100 MHz for category 5.
3.3.1 Velocity of propagation (phase velocity)
The requirement is not specified but may be Indicated in the relevant detail specification.
3.3.1.1 Phase delay
When measured in accordance with A.4.2.1 and A4.3 of IEC 61156-1:2002, the phase delay for any pair of a category 5 cable shall not exceed 567 ns for all frequencies from 2 MHz to 100 MHz.
For category 3 cables, a value Is not specified but may be indicated in the relevant detail specification.
3.3.1.2 DifferentIal phase delay (skew)
3.3.1.2.1 General
When phase delay is measured in accordance with A.4.2,1 and A.4.3 of IEC 61156-1:2002, at (—40 ± 1) C. (20 ± 1) C and (60 ± 1) C, the differential phase delay (skew) for category 5 cables shall not be greater than 45 ns for frequencies from 1 MHz to the highest referenced frequency between all pairs connected to provide a unique transmission link.
For category 3 cables, a value is not specified but may be indicated in the relevant detail specification.
3.3.1.2.2 Environmental effects
The differential phase delay (skew) between all pair combinations due to the temperature shall not vary more than ±10 ns within the differential delay skew of 3.3.1,2. Environmental compatibility shall be within the temperature range from —40 C to 60 C.
3.4Mechanical and dimensional characteristics and requirements3.4.1 Dimensional requirements
The overall diameter of insulation,the nominal thickness of the sheath and the maximumoverall diameter of the sheath are not specified but shall be indicated in the relevant detailspecification.
3.4.2Elongation at break of the conductorsThe minimum value shall not be less than 8 %.
3.4.3 Elongation at break of the insulationThe minimum value shall not be less than 100 %.
3.4.4 Elongation at break of the sheathThe minimum value shall not be less than 100%.
3.4.5Tensile strength of the sheath
The minimum value shall not be less than 9 MPa.
3.4.6Crush test of the cable
The crush test of the cables is not specified, but may be indicated in the relevant detailspecification.
3.4.7 lmpact test of the cable
The impact test of the cables is not specified,but may be indicated in the relevant detailspecification.
3.4.8 Bending under tension
The bending under tension is not specified, but may be indicated in the relevant detailspecification.
3.4.9 Tensile performance of the cable
The tensile strength of the cable is not specified but may be indicated in the relevant detailspecification.
NOTE During installation, the value of the pulling force (in Newtons) based on the cross-sectional area of all theconductors shoulld not exceed 50 Nmm-.
3.5 Environmental characteristics3.5.1 Shrinkage of insulation
When tested at 100 ℃ ± 2 °℃ for 1 h, the shrinkage of the insulation shall not exceed5 %.
3.5.2 Wrapping test of insulation after thermal ageingNot applicable.