Operating Instructions

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Siemens Building Technologies SED2 LON Module Operating Instructions CE1B5193en
HVAC Products 3 Installation and wiring 26.06.2006
3.4.1 Cabling of the LON module
ON
12
SED2
WARNING !
DANGEROUS VOLTAGES
DISCHARGE TIME 5 MIN
ACHTUNG !
GEFÄHRLICHE SPANNUNG
ENTLADEZEIT 5 MIN
ON
12
SED2
WARNING !
DANGEROUS VOLTAGES
DISCH ARG E TIM E 5 M IN
ACHTUNG !
GEFÄHR LICHE SPANNU NG
ENTLADEZEIT 5 MIN
5193V01
Terminating
resistor
52.3 Ohm
close to center
of network
For LON bus cables, either shielded or unshielded twisted pair cables can be used. All
types of bus cables used should be approved by ECHELON. For the bus cables of the
SED2 LON modules, we recommend the exclusive use of shielded twisted pair cables
(earth shielding on one side only). The following types of (shielded) twisted pair cable
have been tested and approved by ECHELON:
Cable type
1
Wire diameter AWG Conductor
cross section
R
loop
Ω/km
nF/km
JY(St)Y
2x2x0.8
0.80 mm 20.4 0.503 mm
2
73 98
TIA 568A
Category 5*
0.51 mm 24 0.21 mm
2
28 48
The maximum transmission distances that can be covered depend on the selected bus
topology and the type of cable used.
Twisted pair bus length with FTT-10A / LPT-10-channel
Free topology Bus topology (serial)
Cable type
Max. node-to-
node distance
Max. total
wire length
2
Only FTT
wire length
FTT / LPT
wire length
TIA 568A
Category 5
≤ 250 m ≤ 450 m ≤ 900 m k.A.
JY(St)Y
2x2x0.8
≤ 320 m ≤ 500 m ≤ 750 m ≤ 750 m
The max. branch line in bus / line topology is 3 m.
1
See Document 005-0023-01M Junction Box and Wiring Guideline for Twisted Pair LONWORKS®
Networks on: http://www.echelon.com/support/documentation/bulletin/005-0023-01M.pdf
2
The maximum cable length in free topologies corresponds to the total length of all network cables
connected within the segment.
For further information regarding LON bus topology, see document
LONMARK Interoperability Guidelines
on http://www.lonmark.org/press/download/lyr1630.pdf
* Don’t use cables of category 6 or 7! These degrade the communication signal.
Recommended
twisted pair cable type
Max. bus length
per physical segment