45xx Modular Disk Subsystem Manual for G-Series Releases

Introduction
45xx Modular Disk Subsystem Manual for G-Series Releases—142466
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Fan CRUs
Fan CRUs
A fan CRU serves as the rear cover of a 45xx disk module. The fan CRU contains two
cooling fans. If one fan within a fan CRU fails, the other fan in that fan CRU increases
speed until the proper air flow rate is attained.
There are two types of fan CRUs: those with ejector latches and those without ejector
latches. Follow the appropriate procedures in this manual for removing and replacing
the type of fan CRU installed in your module. See Replacing a Fan CRU
on page 4-7.
Figure 1-6. Power Distribution in a 45xx Disk Module
008CDT .CDD
Power
Supply
Redundant
Power
Supply*
Midplane Printed Wiring Assembly (distributes 13.8 and 6.3 volts)
13.8 V
6.3 V
13.8 V
6.3 V
Fan 1
Fan 0
Back-End
Board
(BEB)
5 V
Redundant
Back-End
Board
(BEB)*
5 V
*Redundant component available only in the 455mod8 module
** "OR" circuit and regulator in the disk drive
*** "OR" circuit and regulator in the BEB
***
***
**
Disk
** **
Disk
5 V
12 V
**
5 V
**
12 V
Disk
5 V
12 V
**
Disk
5 V
12 V
**
Disk
5 V
12 V
**
Legend
Disk
5 V 12 V
Disk
5 V 12 V
Disk
5 V 12 V