3127 Konnex bus KNX - Siemens

Bus cable
Decentralized bus
supply DPSU
Centralized bus supply
PSU
Distances and line
lengths
8/10
Bus cable requirements as per IEC 189-2 (or equivalent)
Cable type two-core, stranded (red/black)
or 2x two-core, stranded (red/black)
(white/yellow)
or spiral quad
Strands min. 5 / m
Diameter min. 0.8 mm, max. 1.0 mm
Wave resistance (ideal value) 120 Ω at 100 kHz
Line resistance 20 Ω/km to max. 75 Ω/km
Capacity, line to line max. 100 pF/m at 800 Hz
Greater values require a proportional
shortage of the perm. cable lengths.
Cable screen not required (Synco devices without
screen connection)
Bus terminating resistor Not required
Bus supply from Synco RMH / RMU controllers 30 V / 25 mA
Controllers with DPSU, Decentral bus power supply: On max. 8 per line
Bus devices without DPSU max. 2 per controller with DPSU
Number of bus devices on one line max. 24 [8 + (8 x 2)]
Centralized bus supply required if line has >24 bus devices
or only RXB room controllers
or third-party (EIB) devices
or >2 devices without bus supply
per device with bus supply
Centralized bus supply: Devices with integrated throttle
• EIB voltage supply, 320 mA, REG
Type / Manufacturer SV/S 30.320.5 / ABB
Supplier ID GH Q631 0038 R0111
• EIB voltage supply, 640 mA, REG
Type / Manufacturer SV/S 30.640.5 / ABB
Supplier ID GH Q631 0048 R0111
• Voltage, nominal bus supply DC 30 V
(PSU output = DC 30 V / SELV)
The indications for distances and line lengths in a network are designed for bus cables
certified by either EIB or KNX.
• The following applies to networks with centralized bus supply:
Distance of two power supply units with integrated throttle min. 200 m
Distance to bus unit of next neighboring PSU max. 350 m
Distance between bus devices max. 700 m
Total length of all lines on one line max.1000 m
• For networks with decentralized bus supply, the distances are valid in addition in
dependence of the number of controllers with Decentral bus power supply: On (DPSU).
The following applies:
Number of
controllers with
DPSU
Controller with
DPSU
to bus device
Maximum distance
Bus device
to bus device
Total length of all lines
on one line
1 350 m 350 m max. 350 m
2 350 m 700 m max. 700 m
3 to 8 350 m 700 m max. 1000 m
There is no minimum distance between controllers with DPSU.
Siemens Building Technologies Data sheet Konnex bus Preliminary Editon 17.01.2003 CE1N3127en
HVAC Products 17.01.2003