BGW 150 - Rack Mounting Guidelines; Maintaining Airflow and Cooling; Physical Installation in Racks

02650
RACK
MOUNTING
HINTS
KEEPING
IT COOL
A
power amplifier
draws
energy
from a
primary
electrical
service,
usually a
120
VAC
outlet,
to
drive
loudspeaker
systems
with an
audio
signal.
Typically,
only
half
of the
energy
can be
delivered to
the
loudspeakers;
remaining
energy is
converted
into heat,
and must
be dissipated
(ventilated)
into the
air.
Air
circulating
past
heat-producing
components,
absorbs
the
heat
and
carries it
away. To
accomplish
this,
low
and medium
power
amplifiers
rely
on
natural
convection
currents,
while
most
high
power
amplifiers use
fans. If
the air
flow is
impeded,
the resulting
rise in
heat may
cause
an
amplifier to
stop
working
or fail.
Circulating
air
currents
must not be
cut off
when
installing
power
amplifiers
in
racks.
Power amplifiers
using
convection
cooling
require spacing
between
amplifiers to
permit air
flow
between
them.
Power
amplifiers
using
forced-air
cooling,
on
the other
hand, can
usually
be
stacked
closer
to each
other
and may
not
need
any
blank
panel spacing
between
amplifiers.
To
improve
natural
convection
currents
within
a rack, a
chimney can
be
created
by
closing
the back of
the
rack and
venting
the
rack at
the
bottom to
let in
fresh
air,
and
at the top
to exhaust
hot air.
Vents
should
be
large
rectangular
slots
approximately
19"
wide
by
4"
high.
The rack
cabinet will
require
some type
of
blower if a
large
air-flow is
required. It
is
best
to
exhaust air
from
the
top of
the rack
rather
than
to blow it
in
from the
bottom.
There will
be
less dust
and dirt in
the
rack
this way, if
the bottom
vent is
sufficiently
large.
INSTALLING
THE
UNITS
Use
care when
mounting
equipment in
a
rack.
Place
the
heaviest
units
near the
bottom
of
the rack and fill
in all
unused
rack spaces
with
blank panels.
Equipment
cannot
always
be
supported by
front
panels
alone.
This is
especially
true
of
amplifiers
whose
depth is
more
than
twice
their
height.
Uniform
support
can
be
insured
by installing
bottom or
side
rails.
When
racks are
to be
transported
or
used in a
mobile
installation,
some
means of
securing
the rear of
the
equipment is
required.
Angle
brackets
either
attached
to
the
bottom, side
rails or
rear
panel
are
practical
approaches.