Siemens SIGMASYS C, Manual

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12 Monitored lines
These limits apply to an FDnet with an expansion capacity of up to 126 elements each with
one load factor.
For example, if you are using IY(ST) Y 2x0,8 mm Ø cable (73 ohms and 100 nF per km), the
following maximum line lengths can be achieved:
•
a loop with a 2.5 km line length
•
a spur with a 2.5 km line length
With IYY 2x0.8 mm Ø cable the loop and T-taps may measure no more than 3.3 km if the ca-
ble is shielded and no more than 5 km if the cable is unshielded (the assembled cable length
depends mainly on the line capacity). Note here that the distance from the furthest element to
each control and indicating panel connection must be no more than 2.5 km.
12.6.7 Load factors
The maximum load factor connection per loop including T-taps is 280
To simplify the calculation, FDnet element numbers are calculated with load factors.
Element
in Fdnet
S-Line C-Line
Load factor in
idle state Additional load
factor on alarm
Optical detector 1 FDO241 FDO221 1 1
Heat detector 1 FDT241 FDT221 1 1
Combination detector 1 FDOOT241 FDOOT221 1 1
Flame detector 1 FDF241-9 FDF221-9 3 1
Linear smoke detector 1 FDL241-9 5 1
Manual detector 1 FDM223 1 1
Alarm sounder 1 FDS221 1 14
Signal base 0 FDSB291 0,5 4,5
4 x IN 1 FDCI222 2 0
4 x IO 1 FDCIO222 3 0
Line disconnector 1 FDCL221 1 0
FDnet transponder 1 FDCIO223 3 0
Table36: List of load factors for elements
In the case of an additional load factor on alarm, alarm indicators or control modules con-
nected to the detector are already included.
For control modules such as fixed close-and-retain systems (FSA) that are actuated by a de-
tector, an additional load factor of 1 must be allowed for in the idle state.
The number of additional signal bases and alarm sounders allowed for a given load factor in
the FDnet can be determined from the following table:
90 / 128 BMT Project Planning Guidelines
Best.Nr. A24205-A337-B970 – Edition 12 (03/07)