2241A Distribution Panel
INSTALLATION
Section 2
2 - 4
Replace the MAIN Fuse. Check that the resistance is
above 10K Ohm, and that both LEDs on the Front Panel
are lit.
Remove the Fuse for the BACKUP Supply. Check that
the resistance is less than 100 Ohms, and that the
BACKUP LED is Off, and the MAIN LED is Lit.
Replace the BACKUP Fuse. Check that the resistance is
above 10K Ohm, and that both LEDs on the Front Panel
are lit.
If the Alarm Logic fails to operate properly, contact
Convex to arrange for return for warranty repair.
2-4 POWER MODULE REPLACEMENT
If it is not
feasible to take the 2241A out of service, a failed power
module can be replaced while the 2241A is in service. A
failed Power module will be indicated by an Alarm
condition (less than 100 Ohms across Audio Output
Connector pins 25/50 ) and the associated LED being
Off.
First check the fuse of the failed supply, and replace if
blown. If the Alarm is still active and LED Off, check the
new fuse to see if it has been blown. If the new fuse is
blown, do not replace it - instead replace the power
modules per the procedure below.
Replacement Power Modules
AC UNITS
Fuse
AC to 12VDC: Astrodyne Model
AFC-12S
1/2
A
12 VDC to +/-12VDC: Astrodyne Model
EC6A05
12 VDC to +5 VDC: Astrodyne Model
EC6A01
Replacement Power Modules
12 VDC Units
Fuse
12 VDC to +/-12VDC: Astrodyne Model
EC6A05
2.0 A
12 VDC to +5 VDC: Astrodyne Model
EC6A01
Replacement Power Modules
24 VDC Units
Fuse
24 VDC to +/-12VDC: Astrodyne Model
EC6A15
1.0 A
24 VDC to +5 VDC: Astrodyne Model
EC6A11
Replacement Power Modules
48 VDC Units
Fuse
24 VDC to +/-12VDC: Astrodyne Model
EC6A25
1/2 A
24 VDC to +5 VDC: Astrodyne Model
EC6A21
POWER MODULE REPLACEMENT PROCEDURE
WARNING.
To avoid electric shock when replacing a
power module while the 2241A Panel is in service, take
extreme care not to touch any of the traces on the
printed circuit board or any wiring.
1. Remove the fuse associated with the failed power
modules.
2. Check that the rear panel signal and power
connectors are secure.
3. Remove four screws from the rack mounting ears,
and slide the 2241A straight forward out of the cabinet
being careful not to release power or signal connections.
Set the 2241A down on a flat surface.
4. Remove six screws from the top of the unit, three
screws from the front, three screws from the rear, and
remove the top cover. Refer to the drawing on Page 2-2
for the locations of the power modules.
5. Note the warning above, and the orientation of the
modules. Remove all power modules associated with
the failed supply by pulling straight up. Check the pin
alignment on the replacement modules and install.
Press straight down to seat the replacement power
modules. (Bumpers on the top cover keep the power
module seated in the socket.)
6. Replace the fuse associated with the failed power
modules. Check that the alarm condition has been
released (greater than 10K Ohms across Audio Output
Connector pins 25/50 ) and that both Power LEDs are lit.
7. Replace the top cover and install six screws in the
top. Install three screws on the front and rear panels that
hold the top cover on.
8. Slide the 2241A back into the cabinet, and install four
mounting screws in the rack mounting ears. Check that
all cabling to the rear panel is secure.
9. Test the individual power modules removed from the
2241A to determine which of the two or three units is
defective. Replace the defective unit so that there is a
complete set of spares available.
2-5 INSTALLATION.
Installation consists of:
configuration of internal switches, mounting, connection
of signal and power, and system testing.
2-5-1 SWITCH CONFIGURATION
. Refer to the 2241A
Block Diagram and Component Location Drawing on
Page 2-2. Remove the top cover. ( Three screws on the
rear and front panels, and six screws on the top of the
2241A. )
Audio Distribution
S1-S7
Audio Distribution is
controlled by Switches S1 to S7.
Factory default
settings have all of these switches set to the
INPUT
(LEFT) Position. With the default settings, each audio
input will be distributed to three outputs. The default
configuration provides a total of 8 Inputs - each of which
is distributed to 3 Outputs.
(1 to 3 ) x 8 => S1-S7 all
INPUT / LEFT
(1 to 6) x 4 => S1,3,5,7 =
BUS / RIGHT
S2,4,6 =
INPUT / LEFT
(1 to 12) x 2 =>
S1,2,3,5,6,7 =
BUS / RIGHT
S4 =
INPUT / LEFT
(1 to 24) x 1 =>
S1,2,3,4,5,6,7 =
BUS /
RIGHT
Other combinations of three outputs are possible. For
example (1 to 9) x 2 plus (1 to 6) x 1. Refer to the
2241A Block Diagram ON PAGE 2-2 or 2-5 for
guidance.
