1
2
COM
0V
+12V
~230VAC
L
N
A
B
Figure C
Safety valve N.C. ~230VAC
1
2
COM
0V
+12V
~230VAC
L
N
A
B
Figure D
Safety valve N.C. 12VDC
K
_
_
K
1
2
COM
0V
+12V
~230VAC
L
N
A
B
Figure F
Safety valve N.C. 12VDC
1
2
COM
0V
+12V
~230VAC
L
N
A
B
Figure E
Safety valve N.O. 12VDC
K
_
_
K
Consult figures A, B, C, D for various safety valve types and detector supply ~230VAC.
Consult figures E and F for various safety valve types and detector supply 12VDC. In these cases the
second jumper must be placed in K position.
Never connect simultaneously the ~230VAC and 12VDC supply to the detector. Such action could damage
the detector.
-
Β
-
Detection Network Mode
In some cases there is a need of detecting the gas leak in various different places of the same building.
The installation of one detector to each one of the rooms must be done. However only one safety valve is
used to the whole building. Consequently only one detector out of the detectors network will be obliged to
drive the safety valve. This detector is called primary and it must be connected as described previously
(figures A, B, C, D, E, F).
The other detectors are called slaves and they must be connected to the primary one. Do not connect the
slave detectors to the safety valve. The following figure shows the necessary connection between the
primary and the slave detectors. All other necessary wiring has intentionally omitted for figure clarity. In the
same figure the jumper position of the slave detectors can be seen. The power supply of all detectors and
the jumper position of the primary detector have been omitted and they have to be done according to the
previous chapter -
Α
- Stand Alone Detector Mode. It is possible (despite unusual enough) the detectors to
be powered from different power sources. i.e ~230VAC, 12VDC.
1
2
COM
A
B
Slave detector 1
F
T
Primary detector
From Slave detector 2
_
A typical installation can consist of one primary detector capable of controlling the safety valve and up to 4
slave detectors. There is no way of connecting two or more primary detectors or more than 4 slave
detectors in a network.
Operation
When the device is supplied with power all luminous indicators are lit for some seconds in a sequential
manner. Then all of them are switched on together and the buzzer sounds loudly. This process is done in
order to assure the proper operation of the indicators. Then the yellow indicator flashes for a period of 2min
as long as the sensing device preheats. Finally if everything inside the device is functioning normally the
yellow indicator shuts off and the green one starts flashing. The device operates correctly.
During the normal operation when gas concentration is higher than the allowed limit the yellow indicator
lights steadily on. This state can be caused from an accidental however small leak of gas. It is not
necessarily dangerous but it has to be considered. This stage is called possible leak stage. If the
concentration remain high for a period of 10s or more the detector goes form the possible leak stage to the
leak stage. The gas supply in this case must be interrupted. The yellow indicator shuts off, the red indicator
lights on and the buzzer sounds loudly. The output relay shuts off the gas supply by the safety valve. While
the gas concentration remains high the device stays in the leak stage. When the gas concentration fall
below the dangerous limit the detector returns to the previous normal operation. However somebody must
manually re-open the safety valve to establish the gas supply.
In case of detector failure the gas supply is being shut off again. In this case the delay of 10s does not
applied. The yellow indicator lights on and the buzzer sounds loudly.
In a detectors net if one or more detectors have been activated the yellow and red indicators of the primary
detector light on, the buzzer sounds and the output relay shuts off the safety valve.
The following table explains the meaning of the indicators.
!
H
GREEN
YELLOW
RED
BUZZER
ΚΑΤΑΣΤΑΣΗ
|
OFF
¿
|
|
,
Normal operation. No alarm.
z
ON
¿
z
|
,
10s delay. Gas detected.
¿
Blinks
¿
|
z
-
10s delay passed. Gas detected. ALARM.
-
Activated
|
z
|
-
Sensor failure.
,
Deactivated
|
¿
|
,
Preheat delay 2 minutes.
z
z
z
-
Test button has pressed. Indicator check.
¿
z
z
-
Alarm coming from slave detector.
Odor of gas could be sensed before the detector alarm. This is normal because the detector measures
continuously the gas presence in the air but alarms only when this concentration exceeds a certain
threshold. Such behavior does not necessarily mean detector failure or wrong installation.
Recurrent Check - Maintenance
After the elapse of every year of operation a operational check is suggested to be carried our from an
authorized personnel. For this reason unscrew the safety screw and remove the front cover. Then press for
approximately 1s the button “TEST” inside the device. Such action causes all the indicators to light on and
activates the sound buzzer and the relay. If any of them didn’t happen the unit must be replaced or
serviced. If the check process is performed normally the device returns to the usual operating mode upon
the completion of it. The safety valve must then be manually reopened.
