GDS Defender Sensor Instruction Manual

TECHNOLOGIES
GDS Defender – Sensor
FLAMMABLE / TOXIC / OXYGEN / REFRIGERANT GAS ALARM
Not for use in potentially explosive atmospheres (zoned areas) Technical Sheet
ref C1714
Operation
The gas sensor continuously monitors the atmosphere for any hazardous gas conditions, on detection of gas the
sensor will indicate the level status by red LED indication and sounder.
LOW alarm (A1), the green indicator will change to slow flashing red and repeat ON/OFF sounder.
An increasing level of gas will cause the HIGH alarm (A2) to activate which is indicated by rapid flashing of the
red alarm indicator, and corresponding increase in sounder rate. Should the over range DANGER alarm (A3) be
reached, the red alarm indicator and sounder will go constant.
Pressing the reset will mute the sounder and only reset the alarm condition once the gas has cleared. Unit Fault is
indicated by the indication LED turning AMBER with a very slow repeat ON/OFF sounder. Alarm Relay Operation
will activate end user selected controls or alarms, details of which should be recorded and kept adjacent to the
alarm unit.
All sensors are supplied gas tested with preset alarm
levels, ready to install and operate.The alarm unit should be
mounted in a position which is accessible, away from direct
heat, in the field of vision and in accordance with the units IP
Rating. Mains supply should be from a 1A fused spur.
SITING THE SENSOR (DETECTOR)
A key feature of the installation is the correct siting of detectors.
Several considerations must be taken into account, the most
important being the density of the gas with respect to air.
HEAVIER THAN AIR GASES (LPG, Propane, Butane,
Refrigerant Gases) – locate at 15 to 20cm above floor level.
LIGHTER THAN AIR GASES (Methane, Natural Gas, Town
Gas) - locate at 5 to 10cm from the ceiling.
EQUAL TO AIR GASES (Carbon Monoxide, Oxygen) - locate
at 1.5 metres above floor level.
Under still air conditions, a ‘lighter than air’ gas such as
methane leaking from a small orifice at ground level, will rise in
a plume the shape of which approximates an inverted cone. As
the gas rises, it draws air from the surroundings and creates a
turbulence. Resulting from this there occurs rapid dilution and,
unless a sensor is positioned within the plume, there will be no
initial indication of a leak.
As gas continues to escape, the diluted concentration rises
to ceiling level and begins to layer. In time the concentration
at ceiling level will increase and this, in turn, will displace air
downwards.
Dangerous levels will, therefore, tend to occur at ceiling level
and the thickness of this layer will increase with the passage of
time.
Ventilation of the room will of course alter the situation
significantly but it should be remembered that if the ventilator
is not at ceiling level, a dangerous concentration can still occur
between the top of the ventilator and the ceiling.
For heavier than air gases such as propane or butane, the
formation of dangerous layers occurs at ground level. These
gases tend to behave like water and will run down gradients
and pool at the lowest point.
The number of sensors required in individual rooms is
determined by the number of possible hazards in the vicinity.
Gas leakage may occur around valves, flanges and anywhere
where gas pipes are jointed. It may be possible to cover several
probable gas leaks in one room by the careful siting of a single
detector. Ducts, trenches and manholes are also likely places
where a build up of heavy gases may collect.
When siting a detector in such places it is most important
to ensure that there is no likelihood of flooding by water, or
excessive dust which may block the sensor mesh element and
prevent gas reaching the sensor.
When monitoring gases outside, those lighter than air will
be quickly dispersed, but gases heavier than air will tend to
form in layers and again causing a dangerous hazard. When
siting detectors outside prevailing winds must be taken into
consideration and adequate protection given against wind and
rain.
POISONING OF CATALYTIC SENSORS
Catalytic elements used in most flammable gas sensors are
liable to be rendered inactive due to ‘poisoning’ by certain
groups of compounds.
In general contact with any gaseous compound capable of
producing an involatile residue upon heating is to be avoided.
Examples of such substances are:
a. Silicon containing vapours, as emitted by silicone polishes,
greases and oils.
b. Petroleum vapours containing tetra-ethyl lead or other
organo-metallic compounds.
Switching ON
Having fully installed the unit switch ON the power from the
fused spur. During the one minute stabilising period the green
LED indicator will flash going constant on warm up completion.
Control or warning devices which have been connected to the
alarm relays should be tested for correct operation.
Unit Test
The unit may be electrically tested by pressing the reset button
for 15 seconds. The LED indicator will flash RED and the
sounder will toggle ON/OFF, alarm relays will activate at which
time attached warning devices or valves should be checked for
correct operation.
Gas Test: To ensure that the sensor responds correctly to the
presence of gas it should be exposed to test gas at six-monthly
intervals. For further details please contact your product
supplier.
Installation - By approved electrical installer

E: [email protected] T: 0113 286 0166 F: 0113 287 8178
GDS TECHNOLOGIES LTD |FUSION POINT |ASH LANE |GARFORTH |LEEDS |LS25 2GA |UK www.gds-technologies.co.uk
TECHNOLOGIES
Technical Sheet
ref C1714
TECHNICAL
Not for use in hazardous zone areas
Sensor Type Flammable – catalytic
Toxic, Oxygen – electrochemical
Refrigerant – semiconductor
CO2 – infrared
Power Supply 18 to 30vDC optional 90~260vAC
Consumption 1.2 W
Alarm Relays
Signal Relay 1 SPCO volt free contact 3A @ 230vAC
Global A1/A2/A3
A2/A3 only option latched/unlatched –
selectable N/E – N/D
Mains Relay A2 (mains option only)
Permanent mains N/E – N/C – solenoid valve
Alarm N/D (valve closed)
Indicators Power (Green LED)
Gas alarm – Green LED to Red
Alarm 1 Slow flash + intermittent sounder
Alarm 2 Rapid flash + high rate sounder
Alarm 3 Constant + constant sounder
Fault Amber + slow intermittent sounder
Sounder 85dB @ 10cm
Permanent mute option
Ambient Temp Operation: -5 to +50°C
Storage: +5 to +55°C
Protection Standard Sensor – IP42
Weatherproof – IP64
Dimensions Standard
L 83mm x H 83mm x D 36mm
Weatherproof
L 145mm x H 145mm x D 60mm
Options Duct sensor probe – L27mm x 28mm diameter
Factory Settings Alarms - latched
Mains Relay - normally energised
Signal Relay - normally de-energised - Active AL1,
AL2, AL3
Testing/ Press and hold the reset button for 15 seconds
Maintenance the relay will activate the LED will flash and the
sounder will toggle ON/OFF. If the sensor is
connected to the Defender control panel the alarm
will be displayed on that zone. Releasing the test
button will return the sensor to normal operating
mode. To ensure that the sensor responds correctly
to the presence of gas it should be exposed to test
gas at six monthly intervals.
For further details contact your product supplier
service technician.
Adjustments Sensor zero in clean air – turn zero pot until the
green zero LED is ON. Calibration – FSD = 4v
measured at (TP2/3) Fig. 2 and (TP2/4) fig. 3 adjust
using gain pot for test gas value.
NOTE: Link selection must be made with power off.
This document is not contractual and the equipment specification may be modified at any time without prior notice.
Fig 1: Mains Input PCB
PCB 317
+24V SIG 0V
Output
Gas Valve
Mains
Supply
90~ 260V
AC
Mains
Input
Relay
L
N
E
E
N
L
Fig 2
NC CNO
NC CNO
Zero
LED
Zero
LED
Relay NE
Latch
Latch
Unlatch
Unlatch
No link
A1 unlatch alarm
A1 A2 A3
A1 A2 A3
Alarms
Alarms
Mute
Mute
J4
J4
+ Sig _
+ Sig _
J3
J3
RV1
Reset
Sounder
Sounder
Reset
J2
J2
J22
J30
program
J30
program
Oxygen
Sensor
Sensor
LED
LED
J5 J9
J18
J13
J24
J11
J11
J10
J20
J9
J14
J7
J15
J19
J17J16 J21J27
J1
EOL
J1
EOL
TP3
TP2
J10
RV2
RV2
RV1
Spare
Spare
DC In
socket
(No control
unit)
DC In
socket
(No control
unit)
Zero
Gain
Gain
Zero
J5 N/E Relay
+ Sig _
+ Sig _
J8
J8
PCB 271
FT
PCB 277
WYP
WYP
Relay
Relay
No link
A1 unlatch
Sensor Volts
J5 + J9 = 2V
J5 = 3V
J9 = 4V
J5 / J9 Open = 5V
Relay SpareTo Controller Links
LinksSpareTo ControllerRelay
J35
J22
J21
J20
J19
J5J2K8K7K6K5
SW1
VR1
J30
J3
J29J32 J33J34
J1
J15
J6
J7
Z1
Z2
Z3
Z4
Z4
J10
J28
J12
J13
J14
J16
Z1 Z2 J3 J4
J17
J36
J18
D98
F7
Zone enable -
fi t link to activate
Zone
enable
links
Z1 - Z4
Spare Links
EOL
A1/A2
latch
unlatch
No link
Lo unlatch
To Combi System
S5
Reset
S1
Test
S2
Inhibit
S3
S4
PC comms
via hyperterminal
Link for relay A2 only
Program
Right - Left
Display Text
Reset
PCB 278
Contrast Adjust
Mains Z1
Zone 1-4 SENSOR INPUTS
Z2 Z3 Z4
+
-
DC O/C 0V
24v Hi Lo 0v
+SIG 0V +SIG 0V +SIG 0V +SIG 0V
L N E
Flt
Global
relay
Mains
selector
115/230
1A
Antisurge
Fuse
24v output 100mA max Sink when inhibit on
Sink when buzzer on
0V
Relay
A1
(Z1)
Relay
A2
(Z2)
Relay
A3
(Z3)
Relay
Flt
(Z4)
NC
C
NO
NC
C
NO
NC
C
NO
NC
C
NO
NE
NE
NE
NE
14
23
Fig. 1
Fig. 2 Fig. 3
TP2
TP4
Flammable Sensor
Fig 3
NC CNO
NC CNO
Zero
LED
Zero
LED
Relay NE
Latch
Latch
Unlatch
Unlatch
No link
A1 unlatch alarm
A1 A2 A3
A1 A2 A3
Alarms
Alarms
Mute
Mute
J4
J4
+ Sig _
+ Sig _
J3
J3
RV1
Reset
Sounder
Sounder
Reset
J2
J2
J22
J30
program
J30
program
Oxygen
Sensor
Sensor
LED
LED
J5 J9
J18
J13
J24
J11
J11
J10
J20
J9
J14
J7
J15
J19
J17J16 J21J27
J1
EOL
J1
EOL
TP3
TP2
J10
RV2
RV2
RV1
Spare
Spare
DC In
socket
(No control
unit)
DC In
socket
(No control
unit)
Zero
Gain
Gain
Zero
J5 N/E Relay
+ Sig _
+ Sig _
J8
J8
PCB 271 FT
PCB 277
WYP
WYP
Relay
Relay
No link
A1 unlatch
Sensor Volts
J5 + J9 = 2V
J5 = 3V
J9 = 4V
J5 / J9 Open = 5V
Relay SpareTo Controller Links
LinksSpareTo ControllerRelay
J35
J22
J21
J20
J19
J5J2K8K7K6K5
SW1
VR1
J30
J3
J29J32 J33J34
J1
J15
J6
J7
Z1
Z2
Z3
Z4
Z4
J10
J28
J12
J13
J14
J16
Z1 Z2 J3 J4
J17
J36
J18
D98
F7
Zone enable -
fi t link to activate
Zone
enable
links
Z1 - Z4
Spare Links
EOL
A1/A2
latch
unlatch
No link
Lo unlatch
To Combi System
S5
Reset
S1
Test
S2
Inhibit
S3
S4
PC comms
via hyperterminal
Link for relay A2 only
Program
Right - Left
Display Text
Reset
PCB 278
Contrast Adjust
Mains Z1
Zone 1-4 SENSOR INPUTS
Z2 Z3 Z4
+
-
DC O/C 0V
24v Hi Lo 0v
+SIG 0V+SIG 0V+SIG 0V+SIG 0V
L N E
Flt
Global
relay
Mains
selector
115/230
1A
Antisurge
Fuse
24v output 100mA max Sink when inhibit on
Sink when buzzer on
0V
Relay
A1
(Z1)
Relay
A2
(Z2)
Relay
A3
(Z3)
Relay
Flt
(Z4)
NC
C
NO
NC
C
NO
NC
C
NO
NC
C
NO
NE
NE
NE
NE
14
23
Fig. 1
Fig. 2 Fig. 3
TP2
TP4
Toxic/Oxygen Sensor