Nexus 21 A1557 - Manual (Page 4)

Document Ref: Nex8inst.doc/Rev0 09.07.00 Page 4 of 30 Originator MC Checked by AC__
Lithium Battery
Caution - danger of explosion if battery is incorrectly replaced. Replace only with same or
equivalent type recommended by the manufacturer. Dispose of used batteries according to
the manufacturers instructions. This battery should be replaced by trained service personnel
only.
!
Aux Fire Aux Flt Aux I/O Repeater Remote inputs Alarm
1
Alarm
2
Network Loop1 Loop 2
Fuse8
24V 1A
Fuse 7
24V 1A
J14
keyboard
port
J5 - PC port
B1 - Lithium
clock battery
U2 EPROM
Fuse 9 24V 3A
0
v
2
4
v
8
v
f
l
t
Processor, display
power and common
fault from PSU
A B N C
on
off
SW 1
Configuration
switches
Silence
alarms
Reset
system
Silence
buzr
Local
evac
Test
alarms
Test
lamps
J12 remove if
zone board
monitoring
required
LBAR1
[See alarm list]
LBAR2
[See alarm list]
LBAR 1 Alarm List.
Comm failed.
Fire.
Alert.
Fault.
Isolated.
Supply fault.
Alarm fault.
Sil alarms.
Sil buzzer.
Sys reset.
LBAR2 Alarm List.
Net enable.
LP1 enable.
LP2 enable.
LP3 enable.
LP4 enable.
LP5 enable.
LP6 enable.
LP7 enable.
LP8 enable.
Proc
failed
J9 Buzzer
enable
Fuse 10
24v 3A
J3
[jumper
not fitted]
2
4
v 8
v 0
v
Loop power
from PSU
0v
5v
24v
Power for
loop
expansion
board
J6 - Network
card slot
J7- Loop 1
card slot
J8- Loop 2
card slot
J4 A1558 expansion
board interface
A1549 zone
board interface
Field terminals
0v
24v
DO-
D0+
Display
terminals
n
0
1 n
c
1 p
1 n
o
2 n
c
2 p
2 p n
o
n
c 2
4
v
0
v
m
x
+ m
x
- r
o
+ r
0
- r
i
+ r
i
- s
a
l r
s
t e
v
c s
b
z c
o
v f
l
t
+ - + -
n
o
+ n
o
- n
i
+ n
i
- l
o
+ l
o
- l
i
+ l
i
- l
o
+ l
o
- l
i
+ l
i
-
!