Power Supplies; Fan Assemblies; Location Of Seven-Segment Numeric Display On; Power Supply Components - IBM System Storage DCS3700 Installation, User's, And Maintenance Manual

Figure 8. Location of seven-segment numeric display on ESM

Power supplies

The storage expansion enclosure has two removable power supplies. The power supplies provide power
to the internal components. If one power supply is turned off or malfunctions, the other power supply
maintains electrical power to the storage expansion enclosure.
Note: To preserve the optimal airflow, do not remove a failed power supply FRU from the DCS3700
chassis until you are ready to replace it with a new FRU.
Figure 9 shows the power supply controls, LEDs, and connectors.
Power connector Power switch
Figure 9. Power supply components

Fan assemblies

The storage expansion enclosure has two removable fan assemblies. Each fan assembly contains two fans.
The fan assemblies pull air through the enclosure from front to back across the drives. The fans provide
redundant cooling, which means that if one of the fans fails, the remaining fan assembly continues to
provide sufficient cooling to operate the storage expansion enclosure. The fan will operate at maximum
speed under the following conditions:
v During the first few minutes after power is applied to the DCS3700 enclosure
Seven-segment numeric display
I
DC
O
Lnk Lnk Lnk
1
8 8
Lnk Lnk Lnk
1
8 8
I
DC
O
LEDs
I
O DC AC
Lnk Lnk Lnk Lnk Lnk
1 2
8 8
ID/Diag
Lnk Lnk Lnk Lnk Lnk
1 2
8 8
ID/Diag
I
DC AC
O
AC
Lnk Lnk Lnk
2
ID/Diag
Lnk Lnk Lnk
2
ID/Diag
AC
Power supply A
Lnk
Lnk
Power supply B
13
Chapter 1. Introduction