RA8000 and ESA12000 Storage Subsystems
1–30
387404-001
EK–SMCPR–UG. A01
Figure 1–18 Cache-to ECB-Connection
Cache
module
External cache
battery
CXO5928A
Unconnected
Unconnected
1.10 Subsystem Cooling
As shown in Figure 1–19, the subsystem is equipped with eight dual-speed blowers. These
blowers pull air in from the front of the cabinet, through the SBBs, array controllers,
EMU and PVA, and exhaust it out the rear. Backplane connectors p12 V dc to
operate the blowers and route the blower status signals to the shelf backplane and the
EMU.
The EMU may be set to automatically increase fan speed or set to a constant fanspeed of
high. Refer to the either the HSG80 Array Controller ACS Version 8.3 Configuration and
CLI Reference Guide or HSZ80 Array Controller ACS Version 8.3 Configuration and CLI
Reference Guide for the
set_emu
commands.
If set for automatic, the EMU switches all operational blowers from low-speed to high-
speed when one or more of the following conditions occur:
•
When a blower is removed
•
When a blower malfunctions
•
When a blower is not rotating at the right speed
•
When the EMU detects an over-temperature condition
When the fault condition is corrected, the EMU returns the blowers to low speed.