Honeywell IQ8Control C Installation Instruction page 79

Connecting an external signalling device with loop monitoring
Monitored activation of external devices involves monitoring the loop for an end-of-line resistor of 10 k Ω . In the
event of an incident, polarity changes between monitoring and activation voltage at the (relay) connection
terminals. The relay switches over from monitoring the loop to activating the external device, such as a
signalling device.
It is imperative to fit a protective diode (e.g. 1N4004 / 1A) in order to prevent the monitoring current, for
example, from activating external signalling devices while monitoring is in progress.
Example using relay K2 (terminal 5 and 6), monitored mode
3 4
S 1
4
5
+
monitoring
-
6
7
4
5
-
alarm
+
6
7
Fig. 67: Schematic wiring of an external signalling device with loop monitoring
R = 10k Ω end-of-line resistor , V= protective diode (1A).
FB 798951.GB0 / 01.09
Fire Alarm Control Panel IQ8Control C/M
K 2
V
R
V
R
-
+
-
+
79