Macro-Tech 24x6 Reference Manual - 3 Installation
Page 10
Macro-Tech 24x6 & 36x12 Power Amplifiers
3 Installation
3.1 Mounting
Macro-Tech amplifiers are designed for standard 19
inch (48.3 cm) rack mounting as well as “stack” mount-
ing without a cabinet. In a rack cabinet, it is best to
mount them directly on top of each other. This provides
efficient air flow and the best support.
Important:
Due to the weight of the unit, it should be
securely fastened at the back of the cabinet.
LEVEL
LEVEL
ON
OFF
30
27
24
21
18
15
12
9
6
3
0
ENABLE
ODEP
30
27
24
21
9
6
3
0
SIGNAL / IOC
18
15
12
CH1
CH2
(3600)
(1200)
19 in
48.3 cm
16 in
40.6 cm
3.5 in
8.9 cm
2.5 in
6.35 cm
SIDE VIEW
Fig. 3.1 Mounting Dimensions
Fig. 3.2 Top View of a Rack-Mounted Unit
AIR
FLOW
AIR FLOW
AMPLIFIER
(TOP VIEW)
RACK
CABINET
16 in
40.6 cm
2 in
(5 cm)
MIN.
IMPORTANT: Be sure the back of
the amplifier is supported.
17 in
43.2 cm
AIR
FLOW
3.2 Cooling
NEVER block the amplifier’s side vents or front air in-
take. Allow at least 45 cubic feet (1.3 cubic meters) of
air flow per minute. All empty spaces in the rack cabi-
net should be covered with blank panels to prevent
improper air flow. The amplifier’s air flow should be aug-
mented with a rack cooling system if its load is less
than 4 ohms and the amplifier must operate at high
output levels. See Section 7 for additional information
on thermal dissipation.
If the air supply is unusually dusty, it may be necessary
to pre-filter it using commercial furnace filters, etc., to
prevent rapid loading of the unit’s own air filter. When
needed, the unit’s filter can be cleaned with mild dish
detergent and water (see Section 4.5).
When mounting the amplifier in a rack cabinet, the side
walls of the rack should be at least 2 inches (5 cm)
away from the chassis as shown in Figure 3.2.
Tip:
An easy way to verify adequate cooling is to ob-
serve the
ODEP indicators while the amplifier is oper-
ating under worst-case conditions. If the indicators
dim, additional cooling is recommended.
If your rack cabinet has a front door that could block
air flow to the amplifier’s air intakes, you must provide
adequate air flow with either a grill in the door or by
pressurizing the air behind the door. Wire grilles are
recommended over perforated panels because they
tend to create less turbulence.
A good choice for pressurizing the air behind a rack
cabinet door is to mount a “squirrel cage” blower in-
side the rack (option 1 below). At the bottom of the
rack, mount the blower so it blows outside air into the
space between the door and the front of the amplifiers,
pressurizing the “chimney” behind the door. This
blower should not blow air into or take air out of the
space behind the amplifiers. For racks without a door,
you can evacuate the rack by mounting the blower at
the top of the rack, so that air inside the cabinet blows
out the back (option 2 below).
BLOWER
(OPTION 2)
BLOWER
(OPTION 1)
AIR
FLOW
FRONT
OF
RACK
DOOR
AIR
FLOW
EQUIPMENT
RACK
(SIDE VIEW)
Fig. 3.3 Proper Air Flow in a Rack Cabinet