KNX/EIB bus cable
KNX/EIB building-automation bus cable to the KNX specification, J-Y(St)Yh 2×2×0.8, green
The KNX/EIB bus cable is the green bus cable to the KNX specification (J-Y(St)Yh 2×2×0.8) for building automation: lighting, shading, climate and access. Supplied to order; the lead time is stated in the quote.
The KNX/EIB bus cable is a bus cable to the KNX specification for KNX/EIB building automation; essentially a J-Y(St)Yh 2×2×0.8 built to KNX requirements (one pair carries the bus, the second pair is a spare / auxiliary). Solid bare-copper conductors (0.8 mm diameter) are insulated with PVC (a halogen-free FRNC/PE insulation variant is also available) and stranded to pairs (star-quad); the assembly is enclosed by a collective (overall) screen of aluminium/polyester foil in contact with a tinned copper drain wire, protecting the bus signals against electromagnetic interference. The outer sheath is green, the KNX-standard colour. The cable meets the KNX specification (system standard EN 50090) and is tested for a 4 kV insulation strength, so bus and mains circuits may be routed in a shared installation. It carries only the SELV bus (typ. 21–30 V DC); it is not for power distribution.
Also known as: KNX cable · bus cable
Applications
- KNX/EIB bus wiring in residential and commercial buildings.
- Control of lighting, shading, climate and access.
What to look out for
- The red/black pair is the bus; the white/yellow pair is the spare.
- CPR class Eca in PVC. Where the cable is exposed to indoor air in a building, the Bbl requires at least Dca; choose the halogen-free version in Cca there, on request.
- A KNX bus requires a cable tested at 4 kV. An ordinary J-Y(St)Y is tested at 800 V and is therefore not a KNX cable.
- Conductor
- Solid bare (plain) annealed copper, 0.8 mm diameter, class 1 acc. to IEC 60228.
- Insulation
- PVC core insulation (halogen-free FRNC/PE variant available).
- Stranding
- Two pairs, star-quad stranded (bus pair + spare pair); cores colour-coded (red/black bus, white/yellow spare).
- Screen
- Collective (overall) screen of aluminium/polyester (Al/PET) foil in contact with a tinned copper drain wire (CAM).
- Sheath
- Outer sheath green, the KNX-standard colour; PVC (flame-retardant IEC 60332-1-2), or halogen-free FRNC/LSZH in the halogen-free variant.
- Peak operating voltage
- 250 V (cable rating); the KNX bus itself is SELV, typ. 21–30 V DC; not for power distribution.
- Test voltage
- 4 kV core/core (KNX verification for shared routing with mains circuits).
- Compliance
- To the KNX/EIB specification; system standard EN 50090.
- Standard
- Base construction DIN VDE 0815 (J-Y(St)Yh); flame test IEC 60332-1-2; halogen-free variant acc. to IEC 60754-1.
- Conductor resistance
- Max. 36.6 Ω/km per conductor (loop max. 73.2 Ω/km) at 20 °C.
- Mutual capacitance
- max. 120 nF/km.
- Insulation resistance
- min. 100 MΩ × km (0.1 GΩ × km).
- Max. conductor temperature
- +70 °C.
- Permitted temperature, fixed
- −30 °C to +70 °C.
- Min. bending radius, fixed
- 10 × outer diameter.
- Reaction to fire (CPR)
- Eca (EN 50575, PVC version); Cca on request for the halogen-free version.
Key figures
| Pairs × mm | R 20 °C per conductor (Ω/km) | Outer Ø approx. (mm) | Weight approx. (kg/km) |
|---|---|---|---|
| 2×2×0.8 | 36.6 | 6.6 | 54 |
Each pair consists of two solid bare copper wires of 0.8 mm (approx. 0.5 mm²). The loop resistance is max. 73.2 Ω/km. The standard KNX construction is 2×2×0.8; a 4×2×0.8 version is also available. Diameter and weight are indicative.
KNX bus cable or J-Y(St)Y 2×2×0.8?
KNX/EIB bus cable
- to the KNX specification
- tested at 4 kV
J-Y(St)Y 2×2×0.8
- not to the KNX specification
- tested at 800 V
They are similar in construction: two pairs of solid 0.8 mm cores under a foil screen with a drain wire. The difference is in the testing. The KNX bus cable is made to the KNX specification, is green and is tested at 4 kV; an ordinary J-Y(St)Y is tested at 800 V. So for a KNX bus, choose the bus cable to the KNX specification.
View J-Y(St)Y →KNX bus cable in PVC or halogen-free?
KNX/EIB bus cable
- green PVC sheath
- CPR class Eca
halogen-free version
- halogen-free insulation and FRNC sheath
- Cca, on request
The standard KNX bus cable has PVC insulation and a green PVC sheath, CPR class Eca. The halogen-free version has halogen-free core insulation and an FRNC sheath, which releases no corrosive halogen gases in a fire; it is available in Cca on request. The two pairs and the screen are otherwise the same. Where the cable is exposed to indoor air in a building, the Bbl requires at least Dca. Choose the halogen-free version there, and wherever the specification calls for halogen-free. The PVC version is for locations without those requirements.
KNX bus cable or RS-485 cable?
KNX/EIB bus cable
- for KNX TP
- solid 0.8 mm
RS-485 1×2×0.20 LSZH
- for RS-485
- stranded approx. 0.20 mm²
They are cables for different buses. KNX TP requires a cable to the KNX specification: green, tested at 4 kV, with solid 0.8 mm cores. RS-485 cable is a screened twisted pair of 120 Ω with stranded cores of about 0.20 mm², for serial buses such as Modbus RTU. Choose the cable that belongs to the bus system.
View RS-485 1×2×0.20 LSZH →
RS-485 1×2×0.20 LSZH
RS-485 bus cable, 1 pair 0.20 mm², 120 Ω, foil and tinned-copper braid, LSZH sheath
Lead time: On request; the lead time is stated in the quote.
RS-485 2×2×0.20 LSZH
RS-485 bus cable, 2 pairs 0.20 mm², 120 Ω, foil and tinned-copper braid, LSZH sheath
Lead time: On request; the lead time is stated in the quote.
RS-485 1×2×0.22 LSZH B2ca
RS-485 bus cable, 1 pair 0.22 mm², 110 Ω, foil and tinned-copper braid, blue LSZH sheath, B2ca-s1a,d0,a1
Lead time: On request; the lead time is stated in the quote.
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