Power Subsystem - IBM TotalStorage DS6000 Series Redbooks

2.9 Power subsystem

The power subsystem of the DS6800 consists of two redundant power supplies and two
battery backup units (BBUs). DS6000 expansion enclosures contain power supplies but not
BBUs. The power supplies convert input AC power to 3.3V, 5V, and 12V DC power. The
battery units provide DC power, but only to the controller card memory cache in the event of a
total loss of all AC power input. The DS6000 power supplies are hot swapable and a single
power supply is able to support the power requirements of an entire enclosure. The second
power supply is supplied by default, meaning you do not need to request redundant power as
a feature.
Each power supply has two integrated fans for cooling the entire enclosure. If a power supply
fails it should not be removed from the enclosure until a replacement one is available. Both
power supplies must be physically present to ensure that cooling air flows correctly through
the enclosure, even if one has failed. If during replacement of the failed supply, you take more
than five minutes to install the new supply, the DS6000 may power off. Replacement,
however, can be accomplished in less than 30 seconds.
Figure 2-18 DS6000 power supplies
The DS6000 power supply has three indicators; they are defined in Table 2-3.
Table 2-3 DS6000 power supply indicators
Indicator
AC Power (green)
40
DS6000 Series: Concepts and Architecture
DC
AC
power
power
Symbol Purpose
AC This indicator shows that main AC power is present. If it
is off then no AC power is being supplied to the power
supply, or the power supply is faulty.
Fault
detected