5 Connecting the Amplifier
All connections must be made by skilled per-
sonnel . Always switch off the amplifier before
making any connection!
To make handling easier when screwing
on the connection cables, all green screw ter-
minals (15, 17, 18, 19) can be disconnected
from their plug-in connections .
1) For making announcements and repro-
ducing music, a PA preamplifier (e . g .
PA-1414MX) is required which allows
connection of microphones and audio
units (e . g . CD player, radio) . Connect the
output of the preamplifier to the input
PGM IN (18) .
2) For making emergency announcements
or other important announcements, the
PA-1250D is equipped with the input
PRIORITY IN (19) . As soon as a line level
signal is available at this input, the input
PGM IN will be muted so that only the
emergency announcement is audible .
3) Connect the PA speakers to the screw
terminal SPEAKER OUTPUT (17) . Make
sure that the total load of the speakers
does not exceed 250 W RMS; otherwise
the protective circuit will respond and
reduce the volume of the amplifier or mute
it (
chapter 6 .2 .3) .
☞
4) To ensure continued operation of the am-
plifier after mains failure, connect a 24 V
emergency power supply unit (e . g . PA-
24ESP) to the screw terminal 24 V⎓ (20) .
5) For remote-controlled activation / deac-
tivation, connect a switch to the screw
terminal AC PWR REMOTE (15) .
6) For remote control of the amplifier
(e . g . via a PC) and for showing the op-
erating parameters of the amplifier on a
display, an RS-485 interface is provided .
For data transmission, the Modbus proto-
col is used (
page 26) .
☞
Connect the PC to the jack RS 485 IN
(14) . To operate another unit by remote
control, connect this unit to the jack
RS 485 OUT .
7) Finally connect the mains cable provided
to the mains jack (13) and then connect
it to a socket (230 V/ 50 Hz) . The LED
STAND-BY (12) lights up .
6 Operation
1) Press the button POWER (11) to switch on
the amplifier . The LED STAND-BY (12) is
extinguished; the LED ON (7) lights up and
the display (1) is illuminated . To switch off
the amplifier (i . e . to switch the amplifier
to the standby mode), keep the button
POWER pressed until the display is extin-
guished .
Alternatively, switch on / off the am-
plifier by remote control via a switch con-
nected to the screw terminal AC PWR
REMOTE (15) . When the amplifier has
been switched on by remote control, the
display shows
[REMOTE]
line
.
STATUS
Note: The amplifier can only be switched on / off by
remote control when it has not been switched on
with the button POWER . To allow for remote-con-
trolled activation / deactivation even though the am-
plifier has been switched on with the button POWER,
open the connected switch and then keep the button
POWER pressed until the LED STAND-BY lights up .
2) To adjust the volume, first press the knob
PUSH / LEVEL (8) for two seconds until
appears on the dis-
VOLUME SETTING
play . Then turn the knob to adjust the
volume . Finally briefly press the knob to
exit the volume setting menu and to save
and lock the volume adjusted .
The display indicates the volume ad-
justed:
VOLUME
[ 00 ] ... [ 99 ]
When a specific volume has been reached,
the green LED SIG (7) lights up . The red
LED CLIP lights up when the amplifier is
being overloaded; reduce the volume ac-
cordingly .
3) Make all other settings via the menu .
Note: When in a menu, press a button within 30
sec onds; otherwise the menu will be deactivated
and any settings you may have made will be dis-
carded .
a) Press the button MENU (2) for two sec-
onds until
EDITING MODE
the display .
b) Press the knob PUSH / LEVEL . The set-
ting menu appears (fig . 3) .
c) The first menu line
selected . Use the button SELECT (3) to
define if the voltage of an emergency
power supply unit connected is to be
monitored (
) or not (
YES
Note: If you use the unit PA-24ESP from
MONACOR for emergency power supply,
deactivate monitoring (OFF) . Since the 24 V
power of the PA-24ESP is only available in case
of a mains failure, the PA-1250D would report
this as a fault even in normal mains operation .
d) To go to the next menu line, press the
button MENU; to change the setting,
press the button SELECT:
to activate / deactivate the
H.P.F?
high-pass filter (200 Hz) for the input
PGM IN (18)
With the setting ON,
AMP SLEEP?
the amplifier will automatically go to
sleep (the message
AMP Sleeping
starts flashing on the display) if the
input signal is missing for more than
one minute . After four minutes with-
out an input signal, the amplifier will
change to the standby mode . As soon
as a signal is available, the amplifier will
be reactivated .
to activate / deactivate
AMP CHECK?
monitoring of the power amplifier . If no
input signal is available at the amplifier,
the power amplifier will be checked by
means of a test signal (the interval of
the test signals can be set) . If a fault is
beneath the
detected, the display will show the mes-
sage
Note: It is only possible to select the menu line
AMP CHECK
has been deactivated . The function AMP
CHECK is automatically deactivated when
the function AMP SLEEP is activated .
Interval TIME
tervals of the power amplifier checks
(½ hour to 24 hours)
e) To save the settings and exit the menu,
press the button ENTER (4) .
ING save
play; then the standard display reap-
pears (fig . 1) .
Note: You can exit the setting menu at any time
by pressing the button ESC (5) . Any settings you
may have made will be discarded .
4) If the amplifier is connected to a PC, ac-
tivate the second setting menu to define
the unit ID and the baud rate:
a) Press the button MENU for two seconds
until
display .
b) Press the button MENU again to acti-
vate the second setting menu (fig . 4) .
c) The first menu line
ID
to define the unit ID .
d) Press the button MENU to go to the
flashes on
next menu line . Use the button SELECT
to define the baud rate .
e) Press the button ENTER to save the set-
tings and exit the menu .
is
BATTERY?
5) Two info menus can be activated for view-
ing the settings (figs . 5 and 6): To activate
info menu 1, press the knob PUSH / LEVEL;
to activate info menu 2, press the button
) .
NO
ENTER / INFO . Info menu 1 also shows the
temperature of the heat sink (
ture ..°C
go to the next menu line . To exit a menu,
press the button ESC / BUZZER or wait for
approx . 30 seconds until the menu auto-
matically disappears .
6.1 Reset
If the amplifier cannot be operated properly
anymore, reset the amplifier by means of the
following two buttons:
MASTER RST (6) to reset the master micro-
CPU RST (9)
Additionally, the button OCP RST (10) is avail-
able which allows you to reset the protec-
tive circuit when
on the menu (
"Overload") .
IMPORTANT! Use a thin, non-conductive
object to press the reset buttons . If the second
microprocessor was reset by means of the but-
ton CPU RST, the master microprocessor must
also be reset by means of the button MASTER
RST for the amplifier to work properly .
(
chapter 6 .2 .5) .
AMP FAULT
☞
when the function AMP SLEEP
to set the time in-
EDIT-
briefly flashes on the dis-
flashes on the
EDITING MODE
Communication
is selected . Use the button SELECT
Tempera-
) . Press the button MENU to
processor
to reset the second micro-
processor
appears
OVER CURRENT
chapter 6 .2 .3, paragraph
☞
9