Doc PS1398
Page 1
The A 4567A is a line monitoring unit or LMU. An
LMU monitors the condition of 100V PA speaker
lines and alerts you if there is a problem with the
wiring.
The A 4567A comes standard with ten separate
zones that have individual LEDs to indicate the
condition of the Line.
Features
• Up to 10 zones monitored
• LED’s to indicate condition of the Line
• Loud alert sound if there is a fault
• Separate rear outputs for the condition LED’s
Installing the A 4567A LMU
The A 4567A can be powered by a 240Vac or
24Vdc. Terminals on the rear are supplied for both.
Hook up the 100V PA amplifier/s to the inputs on
the rear. All the inputs are isolated from each other
so up to 10 amplifiers can be used or any
combination below that number e.g. one amplifier
connected to 2 or more inputs. NEVER connect 2 or
more amplifiers to one zone it will cause major
damage to the A 4567A and the amplifiers.
The output terminals can now be connected to
the speaker lines. A maximum of 500 Watts of load
per zone is allowed. Any more than this will damage
the A 4567A. Any number of 100V line transformer
/ speaker combinations can be used as long as the
total load for each zone is below 500 Watts.
Setting up the speaker runs so they work with the
A 4567A is as easy as installing a 22uf BP capacitor
at the input of each transformer / speaker (please
see figure 3). Install an end of line resistor or EOL at
the very end of the wiring run before the final
transformer / speaker. The end of line resistor must
be 100K Ohm in value and at least .25 Watt or
above. Unused outputs from the A 4567A need to
have a EOL resistor installed across positive and
negative terminals. If these are not installed the
A 4567A will bring up a fault condition for the non
EOL terminated zones.
Powering up the A 4567A
When the A 4567A is powered up the unit then
pauses for about 10 seconds to allow the protected
zones to be checked for the condition they are in.
If there is a fault the A 4567A will alert you with a
loud pulsing beep and the Cancel switch LED will
flash. A short on a zone is indicated on the front
panel by a red LED. An open condition on a zone
will be indicated on the front panel by a yellow LED.
If there are no faults detected, all zones will indicate
good condition with a green LED.
If the A 4567A goes into alarm mode and the
beeping is heard it can be stopped by pushing the
CANCEL button. The fault LED indicators will remain
on until the fault on the zone is corrected. Any new
fault conditions will result in the alarm tone
sounding again and the Cancel switch LED to flash.
From then on no matter how many times the
cancel button is pushed the A 4567A will go into
alarm mode any time there is a new fault condition
on any of the zones. The alarm will not sound again
if a zone goes from a fault (open or short) condition
to good condition.
Remote monitoring of faults
The fault status of the zones can be monitored
remotely by connecting an external buzzer or
warning light to 24Vdc switched outputs. There are
three switched outputs.
One for an open condition, another for a short
condition and a third for either a short or open
circuit condition (combined out). All three outputs
switch 24Vdc in either failsafe or normal mode.
Fault Finding
The A 4567A does not power up: Check that
power is applied to the unit either by a 240Vac or
an external 24V dc source.
Unit continues to go into alarm mode and emits
a loud continuous beep: Push the cancel button
and check the LED display. See which zone is
causing the problem (if all zones are showing
“normal” the buzzer will not sound continuously).
The SHORT LED is coming up on a zone: First
check and see if you have installed the 100K EOL
resistor at the end of the line and the 22uf BP
capacitors on each of the transformer / speakers
that are installed on that line (see Fig.3). If they are
all installed there must be a short across the line,
once removed the A 4567A will go into NORMAL.
The OPEN LED is coming up on a zone: First
check and see if you have installed the 100K EOL
Resistor at the end of the line and the 22uf BP
Capacitors on each of the transformer / speakers
that are installed on that line (see Fig 3.). If they are
all installed there must be a break in the line, once
this is removed the A 4567A will go into NORMAL.
