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65-2643RK-05-04 M2A Transmitter Operator’s Manual
Figure 9: Wiring the M2A Junction Box to a Controller and Alarm Devices
4. Re-install the control PCB (and ribbon cable if necessary). Be sure the ribbon cable is routed down below
the control PCB so it will not be damaged by the cover when it is screwed back on.
5. Secure the M2A junction box cover to the junction box.
6. Make controller, device, and relay connections as appropriate. If shielded cable is used for the PWR/SIG
connections, connect the cable shield’s drain wire to an available chassis ground at the gas monitoring
controller, recording device, or programmable controller.
Start Up
Introducing Incoming Power
1. Complete the installation procedures described earlier in this manual.
2. Verify that all wiring connections are correct and secure.
3. Turn on the incoming power.
4. If necessary, turn on the controller or other monitoring device that is connected to the M2A.
5. The OLED display will indicate the firmware version when the M2A is first powered up and will then count
down a one minute warm-up period before normal operation begins. During normal operation, the display
will indicate the target gas and current gas reading. Verify that the display is indicating the target gas and
current gas reading after the warm-up period is complete and normal operation begins.
NOTE:
Allow the M2A’s detector to warm up for 15 minutes before you continue with the next section,
“Adjusting the Fresh Air Reading.”
Alarm 1
Alarm Device
Fail Alarm
Device
Alarm Device
Power
+
PW
R
/SI
G
-
S
+
Typical Alarm
Wiring Shown
RS
4
8
5
A
B
C
See
Modbus
Wiring
RKI Controller
Terminals
(24 VDC) -
4 - 20 mA In (S)
(24 VDC) +
See
Detector
Wiring
T
O
X
IC
O
X
Y
+
Alarm 2
Alarm Device
C
NC
NO
AL
A
R
M
1
C
NC
NO
AL
A
R
M
2
C
NC
NO
FA
IL
OXYGEN
20.9 %
