INFICON
(WD) 724-250 450 650 -Low Voltage Operating Manual 220627.docx
12/15
E
n
g
li
sh
E
n
g
li
sh
4.3.1
SERVICE MODE
Pressing the
” Reset/Test/Service” button (7) for 10 seconds will inhibit all alarm functions for the
chosen channel for 60 minutes. Service mode is indicated by all LEDs on the chosen channel is
flashing. A new 60 minute inhibit period can be initiated by repeating the process. Normal
operation will be automatically resumed after 60 minutes or can be cancelled by pressing the
“Reset/Test/ Service”
-button briefly.
4.3.2
FAULT MODE
In the event of a detector failure (GV offset < 0,1V) or disconnection of the interconnecting wiring
a fault condition will be indicated by loss of the green 'Active' LED, the other LEDs start to flash
and the alarm relay D is de-energised. In the event of power failure all relays (A, B, C & D) will be
de-energized. Connections are available for an optional battery back-up to enable total continuity
of operation in the event of a power failure. A 4-hour delay can be configured for relay D to
prevent nuisance alarms. This is activated by setting DIP switch (5) no4 on the respective channel
card to 'ON'. The operation of the LEDs will remain unchanged.
4.4 INTERNAL BUZZER AND 24VDC AUXILIARY OUTPUT
The internal buzzer (1) and 24VDC output can be activated by the DIP-switch (4) on the terminal
board and can be user configured to operate from alarm concentration A(no1), B(no2) or C(no3).
Setting the DIP-switch to ON for the respective alarm level selects the appropriate alarm level.
The 24VDC auxiliary alarm output is always activated together with the buzzer. However, by
removing jumper Bb (3) the buzzer can be disabled.
Please Note!
After being powered off for prolonged periods the sensor may take several
minutes to stabilize during which time ‘false’ alarms may be initiated. Such ‘false’
alarm shall disappear within a few minutes.
n 4 FAULT DELAY: ON=4h DELAY, OFF= NO DELAY
n 1
n 2
n 3 ALARM RESET: ON=AUTO, OFF=MANUELL
ON
A
RESET/TEST
TEST TERMINAL
C
B
LED A
LED B
LED C
POWER
ALARM A
ALARM B
ALARM C
(-)
+ 5VDC
GV OFFSET
