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Bosch Security Systems | 04-2003 | 3922 988 43318 en
Digital Congress Network | Installation and Operating Manual | Chapter 10 - Installation Techniques
en | 10-4
Trunk outlets and Tap-offs
Max. number of units connected in series (without the use of extension cables)
The maximum number of units connected in series to a Trunk outlet or Tap-off of a CCU (LBB 3500),
Extension Power Supply unit (LBB 4106/00) and Audio Media Interface unit (LBB 3508/00) is:
• Table-top units
- 50 x Delegate/Chairman discussion units with a PCF value of 1(see Limit 1)
•
Flush mounted units
- 40 x Dual Audio Interface units (see Limit 2),
or 30 x Multi-purpose connection units (see Limit 2),
or 50 x Channel selector units (see Limit 1),
or 24 x Delegate/Chairman Concentus units including interpreter desks with a PCF value of 2.5
(see limit 2).
Limit 1: The maximum cable length is 100 m (328 ft.). The length of cable attached to each unit is 2
m (6.5 ft.), therefore a maximum of 50 discussion units (50 x 2 m (6.5 ft.) = 100 m (328 ft.)) can be
connected even though the maximum PCF value of 60 has not yet been reached.
Limit 2: The maximum total PCF value that can be connected to one outlet is 60. The Dual Audio
Interface has a PCF value of 1.5 (40 x 1.5 = 60) and the Multi-purpose connection unit has a PCF
value of 2 (2 x 30 = 60).
System overload
Each outlet socket is protected against short circuit at the power supply lines, and each has a red LED
indicator (FIG 10-3) to indicate when the trunk-line has exceeded its maximum PCF value. In an
overload situation, when the LED is lit, the system has a built-in delay time of 30 seconds before
scanning the system again for a repeat overload situation. If the overload has been corrected the LED
goes out. Refer to Chapter 10.2 Power Handling Capacity.
FIG 10-3 Overload indication
FIG 10-4 Tap-off limitations
Port 1
Port 2
Rec.
Line
In
Out
In
Out
Symmetrical
Trunk
115V-T4A 230V -T2A
Overload LED
also applicable
for LBB 4106/00
Trunk
115V-T4A 230V -T2A
Tap-off
In
Port 1
Rec.
Line
In
Out
In
Out
Symmetrical
Trunk
115V-T4A 230 V -T2A
LBB 3500/xx Central Control Unit
1
st
Tap-off
LBB 4114/00
LBB 4114/00
LBB 4114/00
LBB 4114/00
1
st
Tap-off
2
nd
Tap-off
LBB 4114/00
2
nd
Tap-off
3
rd
Tap-off
4
th
Tap-off
5
th
Tap-off
4
th
Tap-off
3
rd
Tap-off
LBB 4106/00
Tap-off
Trunk-line
Trunk-lineTap-off
