Bosch AVENAR panel - Page 38

38 en | Planning AVENAR panel
2022-07 | 5.0 | F.01U.378.910
System manual
Bosch Sicherheitssysteme GmbH
U
End
= bus end voltage = 15volt (must not fall below this limit!)
q = cable cross section = 0.503mm
2
(for cableØ0.8mm)
n
E
= number of elements
ρ = specific resistance of copper = 0.0178mm
2
/m)
R
FET
= FET resistance = 0.7Ω (LSN classic) or 0.35Ω (LSN improved),
I
NE
= average current consumption of elements in[A]
I
trans
= transmission current = 0.012A
I
flash
= flash current = 0.018A
Note that the sum of non-isolated cables must not exceed the limit of 500m. The limit of
500m applies to:
– The lines on the inputs of the following modules: FLM-420-RHV, FLM-420-I2 , FLM-420-
I8R1-S, FLM-420-O8I2-S, FLM-420-O1I1, FLM-420-RLE-S
– The NAC line of the FLM-420-NAC module
– The lines to remote indicators: FAA-420-RI-DIN, FAA-420-RI-ROW
The limit of 500m non-isolated cables doesn't count for the conventional lines of the
FLM-420/4‑CON and the lines connected to the relay contacts and open collector outputs.
Note that the maximum cable length must not exceed 3000m.
Using the Diagram for LSN improved
FET resistance = 0.35Ω, fire alarm cable with Ø0.8mm
Example 1:
You want to know the maximum cable length for a given number of network elements and a
given current consumption (n
E
=120, IN
E
=0.5mA). On the X axis, go vertically up at 120 until
you reach the 0.5mA curve. Then, from the point of intersection go horizontally to the left to
the Y axis and read off the maximum achievable cable length. In this example it is 1950 m.
Example 2:
You want to know the maximum number of network elements for a given cable length
(L=1000m, I
NE
=2mA). Starting from the Y axis at 1000, go horizontally across to the right as
far as the 2mA curve and then from the point of intersection vertically down to the X axis.
Read off the maximum number of network elements, in this example it is 73.
i
Notice!
Remote indicators activated by the detector C point:
A maximum additional cable length of 500m is allowed when using remote indicators (e.g.
FAA-420-RI-DIN/FAA-420-RI-ROW).
The total length of installed cable must not exceed the limit of 3000m.