Page 8 of 17 Revision 1.1 Aug 2020
Document No. AlarmLine II Digital EN Controller Installation Instructions
Operating Modes Wiring Diagram Interlock
2.
Interlock
– this mode is for applications which require a fail-safe guarantee that an alarm is only triggered when an overheat condition has been detected.
This mode may also be known as coincidence detection. In this case, the same rated temperature Digital LHD cable should be attached to both zones of the
AlarmLine II Digital EN Controller. The alarm output is only activated when both Digital LHD cables trigger an alarm due to an overheat condition. If one
Digital LHD cable zone input registers an alarm but the second does not, the alarm output will
not
be activated. This is to prevent an alarm if a mechanical or
other issue has triggered one Digital LHD cable and not an overheat condition.
•
Only use Zone 1 fault and alarm outputs in Interlock mode.
•
Two linear heat detection cables with the same temperature rating must be used and a
minimum of two linear heat detection cables must be installed in each protected space.
See the AlarmLine II Digital EN LHD Installation Instructions for the linear spacing specifi cation.
Zone 1: 250m
Zone 2: 250m
+
-
Power supply
250m
- + NC NO
C
NC NO - +
C
+
-
Z
o
n
e
/S
w
it
c
h
/
IO
M
o
d
u
le
Addressable
loop
+
-
RS-485
Modbus RTU
A
EOL
Junction Box
In interlock mode, the 2 zones of Digital LHD cable are intended
to be installed in close proximity to one another such that if a
fire or overheat condition occurs, both cables will activate.
Zone 1
Equivalent wiring
circuit for
zone/switch/IO
monitor module
Z
o
n
e
/S
w
it
c
h
/
IO
M
o
d
u
le
Normally open
alarm contact
Normally closed
fault contact
EOL
Alarmline II Digital
EN Controller
Fault Output
Alarmline II Digital
EN Controller
Alarm Relay
The EOL and A resistor are usually provided with the fire alarm panel or zone/switch/IO module. For
more information please refer to the Fire alarm panel or addressable module installation instructions.
On each zone output group, the Fault '-' (negative terminal) and Alarm NO terminal are connected
by a soldered jumper on the Alarmline II Digital EN Controller PCB.
A
+
-
AlarmLine II Digital EN
Controller
Alarmline II Digital EN Linear Heat Detection Cable Zone
Alarmline II
Digital EN
EOL Unit
