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Bosch Security Systems | 2011-02
Praesideo 3.5 | Installation and User Instructions | 4 | Amplifiers en | 140
The actual spare switch is carried out by a relay. See
figure 8.8 for the situation before spare switching and
figure 8.9 for the situation after spare switching. As long
as the main power amplifier (1) functions correctly, this
relay is energized (see figure 8.8) and the audio is routed
to the loudspeaker line (Lsp Out+ and Lsp Out-
terminals). The spare amplifier (2) does not route any
audio, since it has no connection to any loudspeaker
line.
At the moment the main amplifier (1) goes down, the
relay is de-energized and the switches fall into their
default positions: Spare In - and Spare In + (see
figure 8.9). This means that the audio output of the
spare amplifier (2) is routed to the loudspeaker line
through the main amplifier (1). The configuration
settings (see section 43.3) of the audio outputs are
transferred from the main power amplifier to the spare
power amplifier. The configuration settings of the audio
inputs, control inputs and control outputs are not
transferred to the spare power amplifier.
If an LBB4428/00 amplifier has been taken over by a
spare power amplifier, the amplifier goes to standby and
audio and control inputs do not work. An AVC
microphone on the input is set to OFF and the call
volume goes to maximum for all the required zones.
If an PRS-1P500, PRS-2P250 or PRS-4P125 amplifier
has been taken over by a spare power amplifier, the
amplifier goes to stand-by; the audio inputs do not
work, but the control inputs and outputs remain active.
figure 8.7: Connecting a spare amplifier
Note
It is allowed to connect one spare power
amplifier to more than one main power amplifier.
++––
Control Out Spare In Lsp Out
C NO NC 0V 50V
++––
Control Out Spare In Lsp Out
C NO NC 0V 50V
1
1
Control In
1
2 3 4 5
6
7 8
1
2
Audio In
Network
1 2
++––
Control Out Spare In Lsp Out
C NONC 0V50V
4
3
++––
Control Out Spare In Lsp Out
C NONC 0V50V
++––
Control Out Spare In Lsp Out
C NONC 0V50V
2 1
++––
Control Out Spare In Lsp Out
C NONC 0V50V
Grounded
Signal Ground
Floating
Mains
48V
48V
Battery
48V 12A
Non-isolated input
0
+
115:
100-120V 50-60Hz
230:
220-240V 50-60Hz
T6.3A 250V
T6.3A 250V
.
+0 –+0 –
Class 2
Wiring
Caution
Avis
Risq of electric shock
Do not open
Risque de choc electrique.
Ne pas ouvrir
Control In
1
2 3 4 5
6
7 8
1
2
Audio In
Network
1 2
++––
Control Out Spare In Lsp Out
C NONC 0V50V
4
3
++––
Control Out Spare In Lsp Out
C NONC 0V50V
++––
Control Out Spare In Lsp Out
C NONC 0V50V
2 1
++––
Control Out Spare In Lsp Out
C NONC 0V50V
Grounded
Signal Ground
Floating
Mains
48V
48V
Battery
48V 12A
Non-isolated input
0
+
115:
100-120V 50-60Hz
230:
220-240V 50-60Hz
T6.3A 250V
T6.3A 250V
+0 –+0 –
Class 2
Wiring
Caution
Avis
Risq of electric shock
Do not open
Risque de choc electrique.
Ne pas ouvrir
1
2
Spare
Main
figure 8.8: Power amplifier, before spare switching
100 V
70 V
Spare In +
Lsp Out +
50 V
0 V
Spare In -
Lsp Out -
50 V
100 V
70 V
Spare In +
Lsp Out +
50 V
0 V
Spare In -
Lsp Out -
50 V
1
2