IBM DS4500 User Manual
Replacing
a
power
supply
Attention:
Before
you
replace
a
power
supply,
consider
the
following
factors:
v
Each
power
supply
has
a
built-in
sensor
that
detects
the
following
conditions:
–
Overvoltage
–
Overcurrent
–
Overtemperature
If
any
of
these
conditions
occur,
one
or
both
power
supplies
enter
shutdown
mode.
All
power
remains
off
until
one
of
the
following
events
occurs:
–
You
cycle
the
power
switches
(turn
off
the
power
switches,
wait
at
least
30
seconds,
then
turn
on
the
power
switches).
For
more
information,
see
–
The
power
supplies
automatically
resume
operation
when
the
ambient
air
temperature
cools
to
below
70°
C
(158°
F).
When
the
power
supplies
automatically
resume
operation,
the
DS4500
Storage
Subsystem
also
resumes
operation.
v
You
can
hot
swap
(replace)
a
power
supply
because
the
two
power
supplies
provide
redundancy.
v
Both
power
supplies
have
built-in
temperature
sensors
designed
to
prevent
the
power
supplies
from
overheating.
If
a
temperature
sensor
detects
an
ambient
air
temperature
greater
than
70°
C
(158°
F),
the
“overheated”
power
supply
automatically
shuts
down.
The
second
power
supply
remains
on
as
long
as
its
temperature
remains
below
70°
C
(158°
F).
If
the
second
power
supply
overheats,
it
turns
off
all
power
to
the
DS4500
Storage
Subsystem.
Note:
There
is
a
serious
problem
if
the
air
temperature
inside
the
rack
cabinet
is
hot
enough
to
cause
the
power
supplies
to
shut
down.
v
The
DS4500
Storage
Subsystem
is
capable
of
power-up
recovery
without
operator
intervention.
Once
the
air
temperature
cools
to
below
70°
C
(158°
F),
the
power
supplies
automatically
restart.
An
automatic
restart
resets
the
controllers,
attempts
to
restart
the
hard
disk
drives,
which
has
no
effect
on
the
hard
disk
drives
if
they
are
already
running,
and
returns
the
DS4500
to
normal
operation.
v
When
a
power
supply
fails,
the
green
power
LED
on
the
power
supply
goes
off
and
the
amber
power
supply
fault
LED
is
lit
on
the
front
of
the
DS4500
Storage
Subsystem.
For
more
information,
see
and
v
If
you
replace
the
power
supply
CRU
and
still
experience
problems,
the
DS4500
Storage
Subsystem
might
have
defective
components
or
connections.
Check
the
storage-management
software
for
indications
of
other
component
failures.
When
instructed
by
the
storage-management
software,
replace
a
power
supply
by
using
the
following
procedure:
1.
Check
the
power
supply
LED
on
the
back
of
the
DS4500
Storage
Subsystem,
as
shown
in
Be
sure
that
the
green
power
indicator
light
on
the
failed
power
supply
is
off.
156
IBM
TotalStorage
DS4500
Fibre
Channel
Storage
Subsystem:
Installation,
User’s,
and
Maintenance
Guide