2
G 220 - RGM 12..-22.. C1 Eng. 09.95
We reserve the right to make changes without notice
OPERATION
All the functions of the detector are processed by a CMOS
microprocessor.
When it is powered the detector does not signal alarms for a
period of two minutes so as to give time to the internal sensor,
and to any remote sensors used, to become stabilised. This
conditionis indicated bytheflashing of thegreen LED (fig.2.5).
Following this period the detector is ready to signal an alarm.
The internal sensor, and, if used, the remote sensors, monitor
the gas concentration level in the surrounding air and, in the
event that the pre-alarm concentration threshold is discerned
by one of the sensors, the detector causes the red alarm LED
(fig. 2.4) to flash; in the event that alarm threshold is exceeded,
the detector causes red LED to light and stay lit and, after 30
seconds, the detector also switches on audible alarm and
activates output relay.
The alarm threshold is equal to a concentration of 0.8% (8,000
ppm)ofmethane (naturalgas)in theairand 0.35%(3,500ppm)
ofpropane-LPG,whichcorrespondstoabout16%ofLEL(lower
explosivelimit). Theregulationsrequirethatthealarmthreshold
is below 25% of LEL.
LEL methane (natural gas) = 5 % (50,000 ppm);
LEL propane-LPG = 2.1 % (21,000 ppm).
Consequently,intheeventofagasleak,RGMdetectorsmakeit
possible to intervene in conditions of maximum safety.
DETECTION OF CARBON MONOXIDE
Byconnectingremote sensorSRC358orSRC352todetectorit
is possible to detect the presence of carbon monoxide. The
dangerof thisgas doesnot derivefrom itsflammability butfrom
itshightoxicityforhumansandthisdependsontheconcentration
level and time of exposure to the gas.
Concentration Time Effect
0.01 % (100 ppm) Irrelevant
0.03 % (300 ppm) 60 min. Lethargy
0.05 % (500 ppm) 90 min. Headache, nausea
0.06 % (600 ppm) 90 min. Loss of senses
0.07 % (700 ppm) 120 min. Coma, death
The alarm threshold is equal to a concentration of 0.05 % (500
ppm)of carbonmonoxide inthe airand thepre-alarm threshold
is 0.03 % (300 ppm).
WARNING LEDS
•GreenLED-Line(fig.2.5):Whendetectorispowered,thisLED
flashes for two minutes and then remains lit.
•Red LED - Alarm (fig. 2.4) : When gas concentration reaches
pre-alarm threshold this LED flashes and, when it reaches
alarm threshold, LED remains lit.
•Yellow LED - Sensor fault (fig. 2.3) : Lights up when one of the
sensors is faulty.
OUTPUT RELAY
The output relay can be used in two different ways :
•Normally not energised :
– Programmer (fig. 3.12) with switch 2 on On;
–Undernormalconditions(detectorpoweredandnotinalarm
state) the relay is not energised with contact 5-6 closed and
4-5 open;
– In alarm state, relay is energised with contact 5-6 open and
4-5 closed;
•Normally energised (BSI 7348 requirement);
– Programmer (fig. 3.12) with switch 2 on Off;
–Undernormalconditions(detectorpoweredandnotinalarm
state), relay is energised with contact 5-6 open and 4-5
closed;
–In alarm state,relay isnotenergised withcontact 5-6 closed
and 4-5 open.
LATCHING ALARM
Onceinalarmstate,if programmer(fig.3.12)hasswitch1onOn
(LatchingAlarm),thisstateremainsevenwhengasconcentration
returns below threshold level; to return to normal state it is
necessarytopressresetkey(fig.2.6)foratleastthreeseconds.
If switch 1 is on Off (without Latching Alarm), when gas
concentration returns below threshold level normal functioning
is automatically resumed.
COVER MODULE/OVERALL DIMENSIONS
fig. 2 36
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80
21
130
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3
45
6
COSTER
1 – Base module 4 – Alarm LED
2 – Cover module 5 – Line LED
3 – Sensor fault LED 6 – Reset button
CONSTRUCTION
The detector consist of two parts:
•Basemodule(fig.2.1andfig.3.1)inshockproofplasticmaterial,
suitable for wall mounting, which houses :
– Printed circuit (fig. 3.2), constructed according to Italian
Electrotechnical Committee (CEI) standards, on which are
located : terminal block for electrical connections (fig. 3.9),
programmer(fig.3.12),microprocessor(fig.3.13),resetbutton
(fig.3.14),alarmbuzzer(fig.3.11),sensingelement(fig.3.10),
transformer(fig.3.7)andairtightoutputrelaycontaininginert
gas (fig. 3.8).
– Cutout for passage of leads from rear (fig. 3.4).
–Mountingholes(fig.3.3)whichareastandarddistanceapart
andthereforesuitable for fixingto a flush-mountingpattress
if required.
– Hinge elements (fig. 3.5).
•Cover module (fig. 2.2), in shockproof plastic material, on the
faciaofwhich are the sensorfault, alarm and lineLEDs(fig. 2.
3.4.5).Thetwomodulesareattachedtoeachotherbyengaging
thecorresponding hinge elementsandby meansof securing
clip on base module (fig. 3.6) and catch on cover module.
BASE MODULE
fig. 3
1 – Base module 8 – Output relay
2 – Printed circuit 9 – Terminal block
3 – Mounting holes 10 – Sensing element
4 – Cutout for leads 11 – Alarm buzzer
5 – Hinge elements 12 – Programmatore
6 – Securing clip 13 – Microprocessore
7 – Transformer 14 – Reset button
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83.5
6
3
9827
1
4
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5
11
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3
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