SenseAir aSENSE m III Safety guide

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Manual for Installation
aSENSE™ m III
in industrial wall mounted housing
CO2/ CO sensor with built-in general purpose
controller
7
5
9
83
6
4
2
10
10
1
Fig. 1
1 Wall plate
2 PCB (Factory supplied
mounted in box)
3 Temperature sensor for
internal compensation (not
shown)
4 RH sensor for internal
com
p
ensation
(
not shown
)
5 Carbon monoxide sensor (not
shown)
6 Hole for wall plate hooks
7 Snap-in lid
8 Locking screw of the lid (not shown)
9 PG9 cable entry bushing
10 Air holes

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Fig. 2
11 Lidlocking screw
12 Wall plate
13 Screw to hold the wall plate
14 Marking to drill hole for PG7
15 Marking to drill hole for PG9
Wall Mounting Instruction
1. Dismount the wall plate. The sensor is delivered with the wall plate mounted. The wall
plate has to be removed before the sensor is mounted onto the wall. Unscrew the screw
on the side of the box. See figure 3.
2. Screw the wall plate onto the wall. The sensor should be mounted 1 to 1,8 m above
the floor. The wall plate has holes for three screws. Drill holes for 3,5mm screws and
put dowel into them. Dowels and screws 3,5 x 25mm are included in a plastic bag
3. Attach the sensor box to the wall plate. It is done by a snap-in fitting. The wall plate
has three hooks that fit in holes in the sensor box. Fasten the screw on the side of the
box.
4. Electrical cable entry. The box has a factory mounted cable entry bushing in
dimension PG9. Never feed more than one cable through each cable entry bushing, or
else gas might leak through!
The lid can be locked with the screw (11) at the bottom of the sensor box.
Please note! Normally the PCB should not be removed from the
housing. If for some reason the PCB must be removed it must be
handled carefully and protected from electrostatic discharge.

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Electrical connections
The power supply has to be connected to G+ and G0. G0 is considered as system ground. The
same ground reference has to be used for the aSENSE™ m III unit and for any connected
device! Unless different transformers are used, special precautions need to be taken.
PLEASE NOTE! The signal ground is not galvanically separated from
the aSENSE™ m III power supply!
PLEASE NOTE! The same ground reference has to be used for the
aSENSE™ m III unit and for the control system!
Connection
Terminal
Function Electrical Data Remarks
G+
G0
Power (+)
Power ground (-)
24 VAC/DC+ (+-20%), 3W
24 VAC/DC-
2W without output load
See note 1!
OUT 1
OUT 2
M
Analogue Output 1 (+)
Analogue Output 2 (+)
Signal Ground (-)
0-10 VDC or 0-20 mA,
2-10 VDC or 4-20 mA,
Same as Output 1
Connected to G0 via PTC fuse
According to positions of
OUT1 jumper and start
point selection.
See note 2!
According to positions of
OUT2 jumper and start
point selection.
See note 2!
See note 1!
Relay
Relay
Normally closed
Open at alarm situ-
ations and power loss
Contact free relay
minimum load 1mA/5V
rated load 0,5A/125VAC;
1A/24VDC
Triggered by register
OUT3
OUT4
Analogue Output 4 (+)
or Open Collector
0-10 VDC
Max 0,5A, 55VDC / 40VAC
(half-wave rectifier protection)
According to positions of
OUT4.
See note 2 & 3!
DI1
Digital Input 1 Closed contact current 1mA Open contact voltage max 5V Do not apply any voltage
on this input!
Table I. Electrical terminal connections for aSENSE™ m III
Note 1:The ground terminal is used as negative power supply DC input or AC phase ground G0
(halfwave rectifier). The signal ground M, protected by a PTC resistor, is the same as power ground
G0 (permitting a ”3-wire” configuration). A single transformer may be used for the entire system.
Note 2:
aSENSE™ m III can deliver both a voltage or a current loop for OUT1/OUT2. For OUT4 a
voltage output or an open collector output is selected with jumper OUT4. To change between voltage
and current output mode the hardware jumpers are used. There is one jumper for OUT1 and one for
OUT2, so that one output can be a voltage output and the other a current output. Both, voltage output
and current output, can have start points 0 % (0-10 VDC or 0-20mA) or 20% (2-10 VDC or 4-20mA)
selected from PC software. See the function manual.
Note 3:Current of Open Collector is internally returned to G0 terminal.

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Fig. 3.Terminals and jumpers on
aSENSE™ m III .The darker positions are default settings.
No. Label Function (configurable)
3 OUT1 CO-transm. 0…100 ppm
4 OUT2 CO2-transm. 0…2000 ppm
6, 7 OUT3 Gas alarm CO >35 ppm
or CO2>1500 ppm
8 OUT4 Drift disturbing alarm or gas alarm
9, 10 DI 1 Extra terminal.Test function (N.O.)
If more holes are needed the box has several drill markings for holes in two dimensions,
PG7 and PG9. Then fasten the cable entry bushing and seal properly. Never feed more than
one cable through each cable entry bushing, or else gas might leak through!
The PCB can be removed during the making of holes. The PCB must be handled carefully
and protected from electrostatic discharge!
If the PCB is in the housing when the hole is made a background calibration, CALb, using the
push buttons should be made. See the function and maintenance description.
Start-up of the aSENSE™ m III
Connect the power directly after mounting. The unit works best if the sensor is continuously
powered. The analogue outputs do not need to be connected before use. An internal delay
function prevents the alarm functions of the relay and OUT4 output during 15 minutes after
power up. After short power failures the CO measurements need this power up time to
stabilize. The alarm outputs may be tested after the 15 minutes delay by shorting the switch
DI1. After long power failures the sensor may need several days to restore the measuring
functions.
NOTE! The CO probe gives incorrect readings near some chemicals, e g
silicone. This makes certain environments unsuitable for the sensor.
1 2 3 4 5 6 7 8
9 10
Switch for
alarm test
Serial
communication
port UART
Jumper for
configuring the
linear output
start point to
0% or 20%
start point
Jumper to choose
between open
collector or 0-10V
linear signal
Jumpers to
choose
between
voltage or
current outputs