422 dual support system support system variant 2

4.2.2 Dual Support System
Support system, variant 2 includes an extended EC bus with more capabilities,
allowing to connect two support systems through the EC ports, depending on
the chosen configuration. The connected support systems result in a dual
support system configuration, where the two support systems constitute one
main unit. Climate, alarm, and synchronization of both support systems are
controlled by the primary DU. Each support system has its own power feed
and provides power to its hosted DUs. The support systems in the main unit
host one DU each.
Main Unit Description
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It is only possible to connect two support systems using the EC bus. If more
than two support systems are used, they are treated as separate systems.
WCDMA and LTE support dual support system configurations using the EC
bus. Multistandard mixed mode do not support dual support system
configurations connected with the EC bus.
More information about EC bus cabling can be found in Non-RF Connections .
More information about DU and SUP compatibility can be found in
Configurations and Compatibility on page 18.
GSM
GSM does not support dual support system configurations. If two or more
support systems are installed, they are considered to be separate systems.
WCDMA
It is possible to extend the main unit with a second support system to create a
dual support system configuration. Each support system in the main unit hosts
one DU, and a dummy unit or a TCU or Baseband T, depending on the
configuration. The primary DU controls the fans in both support systems.
LTE
It is possible to extend the main unit with a second support system to create a
dual support system configuration. Each support system in the main unit hosts
one DU, and a dummy unit or one DU and a TCU, Baseband T, XMU or
Baseband R, depending on the configuration. The primary DU controls the
fans in both support systems.
4.3 Fan Module
The fans are located in a replaceable fan module at the back of the main unit.
The fans cool the installed units and the internal electronics of the support
system.
Note:
Different types of fan modules are used for the support system
variants. The fans are not interchangeable.
Table 11 shows support systems and fan module compatibilities.
Hardware Architecture
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Table 11 Support Systems and Fan Module Compatibilities
Support System
Support System
Spare Parts Kit
Fan Module
Variant 1, −48 V DC 1/BFL 901 009/1
Note: To be replaced
with a Support
System Variant 2 if
faulty, use NTK 102
243/1.
Fan Module (3 fans),
BKV 301 331/2
Variant 2, −48 V DC 1/BFL 901 009/4
NTK 102 243/1
Fan Unit (4 fans),
BKV 106 135/1
NTM 101 2589 /1
Fan Unit (3 fans),
BKV 106 135/2
Variant 2, +24 V DC 1/BFL 901 009/5
NTM 101 2589 /2
Fan Unit (4 fans),
BKV 106 135/1
4.4 Movable Brackets
The movable brackets can be placed in a 0 mm, a 58 mm, or an 80 mm
position from the front of the main unit to ensure that the main unit fits in racks
with different depths.