Bosch Appliances 3.5 manual 11: Spare amplifier and loudspeaker, connections, inputs

Praesideo 3.5 Installation and User Instructions 4 Amplifiers

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10.3.5.3 Spare amplifier channel

A spare amplifier channel can be made available as a back-up channel for all channels of all basic amplifiers. The only restriction is that all the basic amplifiers must be connected to the same multi channel interface. The connection from the spare amplifier channel can be made as a loop through to all the channels of the basic amplifiers.

Make sure that the power rating of the spare amplifier channel is the same as or higher than the power rating of the main channels.

Spare and main amplifier channels can be part of the same amplifier. Use a back-up power supply to avoid that the power supply is a single-point of failure.

A supervision board connected to the last Spare In connection gives supervision to the spare channel.

If channel 2 in the figure 10.11 has a failure, the spare channel becomes active and supports all settings of channel 2. If Channel 1 in the figure 10.11 also has a failure, the spare channel does not support channel 1, but remains with channel 2.

To connect the spare channel to the basic amplifier channels, proceed as follows:

1Connect the + A Lsp Out from the spare amplifier channel to the + Spare In connection of Channel N

of the basic amplifier.

2Connect the - A Lsp Out from the Spare Amplifier channel to the - Spare In connection Channel N of

the basic amplifier.

3Make a loop through connection to all channels of the basic amplifiers that need spare channel back-up.

4Optional: connect a supervision board to the last channel Spare In connection.

Channel 16	Spare input
	A	Active spare channel
	B
Channel 1	Spare input
	A	EOL 1A
	B	Channel 1
		EOL 1B
Channel 2	Spare input
	A	EOL S
		EOL 2A
	B	Channel 2
		EOL 2B
		Signal from active spare

figure 10.11: Spare amplifier and loudspeaker

connections
1			2
Spare In	Lsp Out		Spare In	Lsp Out
+ – + – + – + – + – + –
	A	B		A	B

figure 10.12: Basic amplifier outputs and spare channel

inputs

Bosch Security Systems 2011-02