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Danfoss GDA Mode D'emploi page 7

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ENGLISH
Installation
General procedure for all GD types (fig.
2, 3, 4)
All GD products are for wall mounting.
Removal of GD top cover:-
For Standard and LCD display types:
• Unscrew two front screws
For the models
IP 65 with stainless steel sensor head /
EExd / IP 65 low temperature
(fig. 3, 4):
• Unscrew four front screws
Electrical installation (fig. 5 and 6)
The Earth/Ground connection must be
made when using the standard, LCD
display, or EExd enclosuretypes. The
safety of the equipment is dependent on
the integrity of the power supply and the
earthing of the enclosure.
Apply voltage at CON 1 and the green LED
will light up (fig. 6).
Stabilisation Period
Once the GD is initally powered up it takes
some time to stabilise and will give a
higher analog output (4-20 mA/0-10 V/0-5
V
) ) at the start before reverting to the
1
actual concentration reading (in clean air
and no leaks, on the analog output reverts
back to:
(~ 0 V/4 mA / ( ~ 0 ppm))
).
2
The stabilisation times specified below are
only intended as a guide and may vary due
to temperature, humidity, cleanliness of
the air, storage time
) e.t.c
3
Model
GDA with EC sensor ...........................20-30 Sec
GDA with SC sensor ............................... 15 min.
GDA with CT sensor ............................... 15 min.
GDA with CT sensor, EExd model ........7 min.
GDHC/GDHF/GDHF-R3
with SC sensor ............................................1 min.
GDC with IR sensor ..................................10 sec.
GDC with IR sensor,
EExd model .................................................20 sec.
GDH with SC senso ..................................3 min.
When changing any jumper position, the
power must be disconnected (CON1) to
enable the new jumper setting.
Setting of normally open (NO) / normally
closed (NC) for the digital output Low/
High Level alarm.
Both have an option to set at NO or NC.
Factory setting is NO.
)
1
Always use the voltage 0-10 V to check the
output for stabilisation check.
)
2
GDC IR goes back to about 400 ppm as this is the
normal level in air. (~4.6 mA/~0.4 V/ 0.2 V)
7
NO/NC can not be used as fail
safe during power failure.
Digital output Low Level alarm
NO : JP3 ON, JP4 OFF (removed)
NC : JP4 ON, JP3 OFF (removed)
(fig. 6)
Digital output High Level alarm
NO : JP5 ON in upper position
NC : JP5 ON in lower position
(fig. 6)
Manual reset / auto reset of Low/High
Level alarm (fig. 6)
This option available through JP8 (Low
Level alarm) and JP7 (High Level alarm).
The pre-set factory setting is Auto Reset.
If manual reset is selected for either Low/
High Level alarm condition then manual
reset push button is located next to CON 7.
Digital output Low Level alarm
Auto Reset : JP8 in left hand position
Manual: JP8 in right hand position
Digital output High Level alarm
Auto Reset : JP7 in left hand position
Manual: JP7 in right hand position
Adjusting delayed response time (fig. 6)
The digital output for Low/High Level
alarms can be delayed.
The pre-set factory setting is 0 Minutes
Digital output Low Level alarm
JP1 in position
1 : 0 minutes
2 : 1 minutes
3 : 5 minutes
4 : 10 minutes
Digital output High Level alarm
JP2 in position
1 : 0 minutes
2 : 1 minutes
3 : 5 minutes
4 : 10 minutes
Adjusting Low/High alarm values (fig. 7)
All GD have been preset by the factory to
realistic values related to the actual ppm
range of the GD product. The actual Low
and High alarm ppm limits are detailed on
the external GD label. The factory preset
value can be adjusted, with a voltmeter
measuring the 0-5 V d.c output.
0 V corresponds to the min. ppm range
(e.g. 0 ppm)
5 V corresponds to the max. ppm range
(e.g. 1000)
E.g. if a setting of 350 ppm is required then
the voltage shall be set to 1.75 V (35 % of
5 V)
)
3
If the GD have been in long-term storage or have
been swiched off for a long period, stabilisation
will be much slower. However within 1-2 hours
all the GD types should have dropped below the
low alarm level and be operational.
The progress can be monitored exactly on the
0-10V output. When the output settles around
DKRCI.PI.S00.A4.52 / 520H2528
Adjusting the Low alarm limit value
Between TP0(-) and TP2(+) a voltage
between 0-5 V can be measured and with
that the ppm Low alarm limit setting.
The voltage/ppm setting can be adjusted
at RV1.
Adjusting the High alarm limit value
Between TP0(-) and TP3(+) a voltage
between 0-5 V can be measured and with
that the ppm High alarm limit setting.
The voltage/ppm setting can be adjusted
at RV2.
Connecting GD to a Danfoss monitoring
system (fig. 8 and 9)
Wiring (fig. 8)
All GD must be connected A-A, B-B,
COM – COM (screen)
When connecting to the Danfoss
monitoring system panel the same
terminals are connected to each other i.e.
A-A, B-B, Com – Com.
On the last GD and Danfoss monitoring
system, fit a 120 ohm resistor across
terminal A and B to terminate the
communications system.
A maximum of 31 GDs can be connected.
If more than 31 units are needed, please
contact Danfoss for further information.
GD address (fig. 9)
The sensor address is set by S2 and S3,
adjusting these dials between 0 and F will
give the sensor its own address as shown in
fig. 9. A conversion chart between Danfoss
monitoring system channel numbers and
the hexadecimal address of the GD is
attached. Power must be removed when
setting addresses on the GD.
Annual Test
To comply with the requirements
of EN378 and the F GAS regulation
sensors must be tested annually.
However local regulations may
specify the nature and frequency
of this test. If not the Danfoss
recommended bump test
procedure should be followed.
Contact Danfoss for details
After exposure to a substantial gas
leak, sensor should be checked and
replaced if necessary.
Check local regulations on
calibration or testing requirements.
zero (400 ppm in the case of IR CO
GD is stabilised. In exceptional circumstances
particularly with CT sensors the process can take
up to 30 hours.
© Danfoss A/S (AC-SMC/MWA), 2012-07
sensors) the
2

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