The use of different systems from the calibration gas sample cylinder, makes it
impossible to verify the proper functioning of the sensor.
Even when you want to recreate the actual conditions of danger for which pro-
tection the gas sensor is installed, this is inapplicable.
As an example, the supply of gas from the normal home kitchen equipment.
Our detectors are calibrated at 10% LEL (Lower Explosive Limit).
The explanation is simple: lets suppose to have a kitchen measuring 3 meters.
wide by 4 meters in length, and with height of 3 meters.
- The volume of the kitchen is equivalent to 4 x 3 x 3 that is 36 m3, equal to
36,000 Lt.
When 4,4% of the volume of the kitchen, is filled of natural gas, in the room a
dangerous mixture is created.
- This 4,4% is called L.E.L (Lower Explosive Limit).
- In our case a 4,4% of 36.000Lt correspond to 1584Lt. (L.E.L.).
- Our detectors, according to the IMQ approvals operate at 10% of the LEL,
then 10% of the value of 1584Lt, that in this case is 158,4LT, THEREFORE
ONE THENTH OF THE LOWER EXPLOSIVE LIMIT (L.E.L.)
Taking into consideration the fact that the house cooker has a gas nozzle of
a few tenths of a millimetre and that the gas pressure is of a few millibars, the
gas flow would allow the delivery of 158,4 litres of gas (sufficient to make the
sensor react) only after hours.
Even with broader gas supply sources, the peculiar and strong smell of natural
gas, makes impossible the human presence and it make evident the serious
danger situation even when the natural gas saturation is still too little to allow
the explosion.
LOWER EXPLOSIVE LIMIT (L.E.L.)
You are advised to ask the installer to give the detector a general test at least
once a year.
IMPORTANT: Do not use pure gas, such as that in a lighter, directly on the
sensor since the sensor could be irremediably damaged.
ROUTINE TESTING
N.B. The Sensor module must be replaced by a specialized technician.
The sensor module should be replaced no more than TWICE, for a total
product life-span of 15 years.
Replace the Sensor module if the “FAULT” LED starts blinking, or by the expiry
date on the label on the cover.
Replace the label on the cover stating the expiry date (5 years after the date
of installing the new sensor module); this label must be compiled by the perso
who installs the detector at the time of replacing the sensor module.
REPLACING THE SENSOR
SENSOR MODULE
Code
ZSDM1
ZSDG1
Detected gas
Methane
L.P.G.
Model
SE330KM/SE333KM
SE330KM/SE333KG
N.B. Make sure the code of the new Sensor module matches the code on
the
Sensor module to be replaced.
1 • Turn off the detector, unplug it from
the mains and use a screwdriver to le-
ver off the little cover under the three
LEDs (Fig. 11).
2 • Undo the two screw fasteners on
the Sensor module to be replaced.
(Fig. 12).
3 • Remove the
Sensor module to be
replaced (Fig. 13).
4 • Check the new
Sensor module is
compatible with the one to be replaced
(if the sensor module is not compat-
ible, the
YELLOW LED and BUZZER
turn on) and carefully insert the 4 con-
nectors in the correct place.
5 • Fasten the
Sensor module with
the two screws and close the cover,
first inserting the two tabs at the bot-
tom (Fig. 15). The instrument can now
be turned on.
After the instrument is turned on, the catalytic sensor in the detector takes
about a minute to ‘warm up’, during which time the green LED blinks to indicate
the sensor is warming up and the detector is not operational.
Remove any dust on the surface of the instrument with a cloth.
Do not attempt to open or dismount the gas detector since this could result in
electric shock and damage to the product.
Bear in mind that the sensor is also sensitive to commonly used products such
as sprays, detergents, alcohol, glue and paint.
These products can contain substances which, in high quantities, could trigger
the sensor and cause false alarms.
It is advisable to ventilate the room when using these products.
Do not forget that the detector cannot detect leaks outside the room in which it
is installed or leaks in the walls or under the floor.
The gas (methane or LPG) contains an additive that gives it an unpleasant
odour, to make it easy to detect by smell. If a ring on a gas hob is left on without
being lit, even for several minutes, the amount of gas will not be sufficient to
trigger the alarm of the detector (even though it can be clearly smelt).
In fact, the amount of gas in the room could be under the alarm threshold.
The detector does not work when there is a power cut.
WARNING
FIG11
FIG 12
FIG. 13
FIG. 14
FIG. 15
ATTENTION! In the event of an alarm:
1) Put out all naked flames.
2) Close the valve on the gas meter or LPG cylinder.
3) Do not turn any of the lights on or off; do not use any electrical appli-
ances or devices.
4) Open the doors and windows to increase ventilation in the room.
If the alarm stops, find the cause and take appropriate action.
If the alarm continues and you cannot find and eliminate the cause of
the leak, vacate the premises and, when you are outside, contact the gas
emergency service.
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