Owner's manual
Blowers
The power supply
–mounted blowers cool the enclosure by circulating air through the enclosure. The
blowers, under
the control of the EMU or the associated power supply, can operate at multiple speeds.
This ensures that when the enclosure temperature changes the blowers can automatically adjust the
air flow .
If a blower is operating too slowly or has stopped (a “blower failure”), internal circuitry automatically
operates the re
maining blower at a higher speed. Simultaneously, the error condition is reported in
several ways,
including the power supply indicator, the audible alarm, the enclosure fault indicators,
and the EMU alphanumeric d isplay.
Should both b lowers fail, the power supplies automatically shut down.
NOTE:
The blowers ar
e field-replaceable units and can be replaced, individually, while the system is running.
The blowers a
re also interchangeable. The failure of a power supply +12.5 VDC circuit disables the
associated blower.
The status indicator on the blower (Figure 28) displays the status of both the power supply and the blower.
See Table 11 for definitions of the indicator displays.
Table 11 Power supply/blower status indicators
Blower status
LED
Description
On
Both the power supp ly and the blower are operational.
Flashing
The power supply or the blower locate function is active.
Off
The power supply or the blower is non–operational. W hen
there is a b l ower problem, the other blower runs at a h igher
speed. Recommended corrective actions:
• Check blower for proper operation. Replace if defective.
• Check power supplies for proper operation. Replace if
defective.
Drive enclosure EMU
The EM U provides increased protection against catastrophic failures. The EMU detects conditions such
as failed power supplies, failed blowers, elevated temperatures, and external air sense faults and
communicates these conditions to the storage system controllers.
The EMU for Fibre Channel-Arbitrated Loop (FC–AL) drive enclosures is fully compliant with SCSI-3
Enclosure Services (SES), and mounts in the left rear bay of a dri ve enclosure (see 1, Figure 18).
CXO7971
A
1
Figure 18 EMU location
1. EMU
Controls and d
isplays
Figure 19 illu
strates the location and function of the EMU displays, controls, and connectors.
4000/6000/8000 Enterprise Virtual Array user guide
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