Bosch Appliances 3.5 + – + – + – + – + – +, Ground connection, Connecting the amplifier channels

Praesideo 3.5 Installation and User Instructions 4 Amplifiers

en 170

Proceed as follows:

1 Connect the triangle symbol connector of the MCI to the triangle symbol connector of the basic amplifier.

2Connect the circle symbol connector of the MCI to the circle symbol connector of the basic amplifier.

Audio In		MCI		Audio In
1				2
+ 0	–		MCI Only	+ 0	–

figure 10.5: MCI connections

10.3.4 Ground connection

Connect the ground connection of the unit (see figure 10.2) to the 19 inch rack, which is connected to the safety ground. For good resistance to electrostatic discharges (ESD), it is important that the ground connections of the multi channel interface and the connected basic amplifiers are interconnected with short wires, directly or via the rack. Set the signal ground switch to Grounded in case the audio source is not grounded to reduce susceptibility to external RF disturbances. If the audio source already has the signal ground connected to a safety ground, set the switch to Floating to avoid ground loops that can be a source of hum.

10.3.5 Connecting the amplifier channels

10.3.5.1 Introduction

An amplifier channel (see figure 10.6) is a group of outgoing signals that have been processed by the same amplifier unit of the basic amplifier. The number of amplifier channels depends on the type of basic amplifier.

table 10.2: Number of amplifier channels

Type	Amplifier channels
PRS-1B500	1
PRS-2B250	2
PRS-4B125	4
PRS-8B060	8

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

figure 10.6: Amplifier channel connectors

table 10.3: Amplifier channel connector details

Pin	Description
1, 2	Spare amplifier input. See section
	10.3.5.3.
3, 4	Loudspeaker line A. See section
	10.3.5.2.
5, 6	Loudspeaker line B. See section
	10.3.5.2.

Caution

To prevent the hazard of electric shocks, switch off the basic amplifiers and disconnect the back up power supplies from the basic amplifiers before connecting loudspeaker lines and spare amplifier connections.

Caution

After connecting wires to the amplifier channel connectors, install the plastic safety bracket. The plastic safety bracket makes sure that the amplifier channel connectors cannot be touched.

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