| Full title | Multicore and symmetrical pair/quad cables for digital communications. Part 5: … up to 1 000 MHz, Horizontal floor wiring. Part 6: … up to 1 000 MHz, Work area wiring. Sectional specifications |
| Publisher | IEC, TC 46/SC 46C |
| Current edition | IEC 61156-5:2020 edition 3.0 and IEC 61156-6:2020 edition 4.0, both published 3 April 2020 |
| Status | Published. Part 5 replaces the 2009 edition and Amendment 1:2012. Part 6 replaces the 2010 edition and Amendment 1:2012 |
| Related standards | IEC 61156-1 (generic specification); IEC 61156-9 and -10 (2 GHz); ISO/IEC 11801-1; IEC 60603-7 series; ISO/IEC TS 29125 |
What they cover
IEC 61156 is the IEC series for balanced twisted-pair and quad cables used for digital communications. Parts 5 and 6 are sectional specifications. They sit under the generic specification, IEC 61156-1, and above the detail specification that a cable maker writes for a product.
- IEC 61156-5 covers cables mainly for horizontal floor wiring, as defined in ISO/IEC 11801. This is the fixed installation cable between floor distributor and outlet.
- IEC 61156-6 covers cables mainly for work area wiring. These are the cables used to make patch, equipment and work area cords.
Both cover unscreened, common screened and individually screened pairs or quads. Transmission characteristics are specified at 20 °C. Both say the cables are intended to support low voltage remote powering such as IEEE 802.3af, 802.3at and 802.3bt. Guidance on this is given in IEC 61156-1-4, IEC TR 61156-1-6 and ISO/IEC TS 29125.
Cable categories
Table 1 of each part lists the same categories and the maximum referenced frequency for each.
| Cable designation | Maximum referenced frequency |
|---|---|
| Category 5e | 100 MHz |
| Category 6 | 250 MHz |
| Category 6A | 500 MHz |
| Category 7 | 600 MHz |
| Category 7A | 1 000 MHz |
Categories 8.1 and 8.2, up to 2 000 MHz, are not in Parts 5 and 6. They are in IEC 61156-9 for fixed cables and IEC 61156-10 for cord cables.
Part 5 and Part 6 compared
| Requirement | IEC 61156-5 (horizontal) | IEC 61156-6 (work area) |
|---|---|---|
| Conductor | Solid annealed copper | Solid or stranded annealed copper |
| Nominal conductor diameter | 0.4 mm to 0.65 mm; up to 0.8 mm may be used | 0.4 mm to 0.65 mm; up to 0.8 mm may be used |
| Maximum conductor resistance at 20 °C | 9.5 Ω per 100 m | 14.5 Ω per 100 m |
| Minimum installed bend radius | 4 × cable outside diameter | 4 × cable outside diameter |
| Operating temperature, static | At least −20 °C to +60 °C | At least −20 °C to +60 °C |
| Insulation examples | Polyolefin, fluoropolymer, LSZH thermoplastic | Polyolefin, fluoropolymer, LSZH thermoplastic |
Part 5 requires a solid annealed copper conductor. This rules out copper-clad aluminium conductors. Part 5 also includes a clause on Category 5e multipair cable.
With remote powering, the conductor temperature must not exceed the maximum static operating temperature, to protect the insulation. Extended temperature ranges may be given in the detail specification.
Tests
Test methods are those of IEC 61156-1. Transmission tests are made on 100 m of cable unless stated otherwise. For Category 7A, a 50 m length is recommended for better accuracy at high frequency.
The transmission clauses cover propagation velocity, delay and skew, attenuation, TCL, NEXT, ACR-F, alien NEXT and alien ACR-F, impedance and return loss. Electrical tests include resistance unbalance, capacitance, transfer impedance and coupling attenuation. The 2020 editions added balance levels linked to MICE environmental classification.
Structure of the series
| Part | Content | Current edition |
|---|---|---|
| IEC 61156-1 | Generic specification: definitions, requirements, test methods | Ed. 4.0, 2023 |
| IEC 61156-5 | Horizontal floor wiring, up to 1 000 MHz, sectional specification | Ed. 3.0, 2020 |
| IEC 61156-5-2 | Horizontal floor wiring, up to 600 MHz, capability approval | Ed. 1.0, 2002 |
| IEC 61156-6 | Work area wiring, up to 1 000 MHz, sectional specification | Ed. 4.0, 2020 |
| IEC 61156-6-2 | Work area wiring, up to 600 MHz, capability approval | Ed. 1.0, 2002 |
| IEC 61156-9 | Cables for the fixed part of channels, up to 2 GHz, Categories 8.1 and 8.2 | Ed. 1.0, 2016 |
| IEC 61156-10 | Cord cables up to 2 GHz, Categories 8.1 and 8.2 | Ed. 1.0, 2016 |
Earlier editions cited separate blank detail specifications, IEC 61156-5-1 and IEC 61156-6-1. The 2020 editions include the blank detail specification as informative Annex A, and the IEC webstore does not list -5-1 or -6-1 among current publications.
The 2020 editions still cite IEC 61156-1:2007 and its 2009 amendment as normative references, although the generic specification is now in its 2023 edition.
What it means in practice
- Use Part 5 cable for fixed horizontal runs and Part 6 cable for cords. Part 6 allows stranded conductors and a higher resistance limit.
- A cable datasheet should state the category and the IEC 61156 part it is made to, not just the category.
- The 4 × diameter bend radius is the cable requirement. Installation standards such as BS EN 50174-2 may set their own rules.
- These parts list fire-related tests (flame propagation, smoke, halogen and toxic gas), but the fire performance needed for an installation is chosen separately, for example a CPR class declared to EN 50575 in Europe.
Related reading: Solid vs stranded copper data cable · Why CCA data cable fails.