Amplifier - Bosch PRAESENSA Installation Manual

PRAESENSA
19.3.2

Amplifier

To replace a defective amplifier PRA‑AD60x in a running system proceed as follows:
Prepare the new amplifier
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Exchange the amplifier
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10. Press Save and restart to store and activate the new configuration.
11. Acknowledge and reset the faults in the system. If faults associated to the amplifier can
12. The new amplifier is now operational. There is no need for measuring the connected
13. Perform a test by making calls to the zones associated with the new amplifier and check
14. Make a backup of the new configuration and store on a safe location.
Bosch Security Systems B.V.
Unpack the new amplifier (same model as the one to be replaced).
Supply power to the new amplifier using any available 48 VDC supply (e.g. a PRA-PSM48
or a PRA-MPSx with an unused 48 V output).
Connect a (laptop) PC to the new amplifier.
Start the PRAESENSA Firmware Upgrade Tool (FWUT) and upgrade the new amplifier to
the required firmware version; this is the same version as the original amplifier was using.
– See the PRAESENSA configuration manual.
Disconnect all cables from the original amplifier:
– First disconnect the lifeline connector. There is no audio signal on the lifeline input.
– Then disconnect the Ethernet cables. The network link is lost, so the disconnected
lifeline input is activated.
Then disconnect the 48 VDC connectors. There is no audio signal, so the supply current is
low, reducing arc flashes.
– Finally disconnect the audio outputs; make sure the loudspeaker cables are labeled
correctly.
Remove the original amplifier from the rack and put the new amplifier in the rack.
Connect all cables to the new amplifier:
– First connect the lifeline, Ethernet and loudspeaker cables; make sure the
loudspeaker cables are connected to the appropriate channel outputs. The amplifier
is in sleep mode.
– Then connect the 48 VDC connectors. The DC/DC converters are disabled, but the
inrush current to charge the input capacitors may still cause a spark.
Connect the PC to the system, either to a spare port of the system controller or to one of
the PRA-MPSx.
Go to the System composition web page and click Rediscover to discover the new
amplifier. The amplifier is now discovered but not yet assigned.
The location of the original amplifier is still present and shows the hostname of the
original amplifier.
Select under hostname the new hostname of the new amplifier.
Press the Submit button on the System definition page to add the new amplifier to the
configuration.
be acknowledged and reset, this means that the connection and configuration is correct.
output loads again in Diagnose > Amplifier loads, because the system controller pushes
the values of the original amplifier to the new amplifier.
the audio presence.
Installation manual
Maintenance and service | en 183
2019.11 | V1.00 |