Protective Circuit - Monacor PA-5240 Manual De Instrucciones

5.5 Additional amplifier
If the number of the required speakers is
higher than the number admissible for the
amplifier, an additional amplifier will be
required . Connect the input of the addi­
tional amplifier to the jack PRE OUT in the
area INSERTS (18) . The signal for the addi­
tional amplifier will not be affected by the
zone attenuators (6) .
5.6 Switches for chime and siren
For remote activation of the chime, con­
nect a momentary pushbutton switch to the
contacts "Remote Chime" (30) . For using
the siren, connect a switch to the contacts
" Remote Siren" (30) . To allow activation from
several places, it is possible to connect several
switches or momentary pushbutton switches
in parallel .
5.7 Switch for remote activation /
deactivation
A separate switch allows remote activation
and deactivation of the amplifier . For this
purpose, connect an on­off switch to the
terminal strip AC POWER REMOTE (26) . For
remote activation or deactivation, the ampli­
fier must not be switched on with the POWER
switch (14) .
5.8 Power supply and
emergency power supply
1) For continued operation of the amplifier
after a possible power failure, connect a
24 V emergency power supply unit (e . g .
MONACOR PA­24ESP) to the terminals DC
POWER 24 V⎓ (28) . For a cable length of
up to 4 m, a cable cross section of 5 mm
is required .
Note: If the 24 V voltage from the emergency
power supply unit is present at the terminals DC
POWER 24 V⎓, the amplifier cannot be switched
off with the switch POWER (14) . In case of a
mains failure or if it is switched off, it switches
automatically to the emergency power supply .
2) Finally, connect the mains cable provided
to the mains jack (24) and then to a mains
socket (230 V/ 50 Hz) .
3) Even when it is switched off, the amplifier
will still consume some power . Therefore
disconnect the plug from the mains socket
and, if required, disconnect the emergency
power supply unit if the amplifier is not
used for a longer period .
6 Operation
When the amplifier is switched off and con­
nected to the supply voltage, the LED "stand
by" (11) will light up .
1) Prior to switching on the amplifier for the
first time, set all five input controls INPUT­1
to INPUT­4, AUX (8) and the MASTER con­
trol (9) to zero .
2) Switch on the amplifier with the POWER
switch (14) or with a switch connected to
the terminal strip AC POWER REMOTE (26) .
The LED "stand by" will be extinguished,
and the LED "power" (12) will light up .
10
6.1 Adjusting the volume
1) For the time being, set the control
INPUT (8) of the signal to be heard at the
highest volume to position 7 (e . g . INPUT­1
for emergency announcements in channel
1 of top priority) .
2) Set the attenuator ZONE ATTENUATORS
(6) of the zone to be provided with the
sound of the highest volume to position 5 .
3) Make an announcement via the corre­
sponding microphone and adjust the
maximum desired volume with the MAS­
TER control (9) . However, the LED "clip"
of the VU­ meter (10) must not light up;
otherwise, this will result in overload and
distortion of the amplifier . In this case, turn
back the MASTER control accordingly .
If the desired volume is not reached
and the LED "clip" does not yet light up,
advance the corresponding control INPUT
further .
4) Then, while an announcement is made,
also adjust the volume of the other zones
with the attenuators (6) .
5) Adjust the volume of further microphones
and signal sources with the corresponding
controls (8) . Always set the controls of the
unconnected channels to zero .
6) For selecting a unit connected to the jacks
AUX INPUTS (19), actuate the selector
switch "5 6 7" (3) . For this purpose, first
set the control AUX to zero to prevent
switching noise .
7) Adjust the sound with the two controls
"Bass" and "Treble" (4) . Adjust the sound
for an insertion in the compartment (1)
with the controls PACK (5) .
2
8) For temporary sound interruption in cer­
tain zones, set the corresponding attenu­
ators (6) to "off" .
6.2 Automatic volume attenuation
– A signal in channel 1 will take priority over
all other signals, i . e . the volume of the other
signals will be automatically attenuated if
you speak into the microphone of channel 1 .
– When the talk button of the microphones
PA­5000PTT is pressed, the volume of the
AUX channel will be automatically atten­
uated .
– The input signals will also be attenuated if
the siren or the chime is activated .
The volume attenuation level can be adjusted
from −25 dB to −35 dB with the control
"Mute Level" (31) .
6.3 Chime
The chime can e . g . be activated prior to an
announcement with the key CHIME (2), with
a momentary pushbutton switch connected
to the terminals "Remote Chime" (30), and
with the talk button of a PA PTT microphone .
Adjust the chime volume by means of a
screwdriver at the control "Chime Level" (33) .
To prevent activation of the chime from
the PTT microphones connected to the inputs
2 – 4 (34), remove the jumper from the screw
terminals "INPUTS Chime On / Off" (30) .
6.3.1 Switching over between 2-tone chime
and 4-tone chime
A jumper in the amplifier allows selection of
2­tone chime or 4­tone chime .
WARNING The chime must be switched
over by skilled personnel only .
For this purpose, the amplifier
must be opened . Always dis­
connect the mains plug from the socket be­
fore opening the amplifier; otherwise, you
will risk an electric shock!
1) If an emergency power supply unit is con­
nected, disconnect it from the terminals
DC POWER (28) to make sure that the am­
plifier is definitely out of operation .
2) Unscrew the housing cover of the amplifier .
3) Use the jumper MS 1 on the left PC board
at the rear side of the amplifier to make
the adjustment:
position "2T" = 2­tone chime
position "4TONE" = 4­tone chime
4) Screw on the housing cover again .
6.4 Alarm siren
The siren can be activated via a switch con­
nected to the terminals "Remote Siren" (30) .
Adjust the volume by means of a screwdriver
at the control "Siren Level" (32) .
6.5 GROUND / LIFT switch
If there is a ground loop when all units have
been installed (e . g . from the housing of the
amplifier via a rack to another housing of a
unit), humming will occur (audible in particu­
lar during music passages of low volume) .
This ground loop can be interrupted with the
GROUND/ LIFT switch (29) on the rear panel
of the unit . For this purpose, set the switch to
LIFT . Humming should stop after that .
On the other hand, the amplifier is not
shielded from electric noise fields if the hous­
ing is not grounded . In this case, set the switch
to GROUND . In case of doubt, set the switch
alternately to find the optimum position .

7 Protective Circuit

The amplifier is provided with a protective cir­
cuit against overload, overheating and short
circuit at the speaker outputs . The power
amplifier is ventilated by a fan, the speed of
which depends on the temperature of the
power amplifier . If the temperature rise is too
high despite the ventilation, the amplifier will
be muted and the red LED "prot" (13) will
light up . In this case, turn the MASTER con­
trol (9) to zero, wait until the LED "prot" is
extinguished, then switch off the amplifier .
Eliminate the fault, e . g .:
1 . In case of overload, reduce the number of
speakers connected or, if possible, adjust
a lower power consumption on the speak­
ers . Use a second amplifier, if required (see
chapter 5 .5) .
2 . In case of overheating, provide an im­
proved air circulation .
3 . In case of a short circuit at a speaker out­
put, locate the short circuit and eliminate it .