65-2640XL-04 M2A Transmitter Operator’s Manual
Chapter 3: Installation & Startup
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• If the PWR/SIG connections and one or more relays are used, route the connections to the
M2A in conduit. Use shielded cable in the conduit for the PWR/SIG connections and
unshielded cable or individual wires for the relay connections. Make sure any wire or
cable used for relay wiring is appropriately rated for the power that it will carry.
CAUTION:
If shielded cable is used for the PWR/SIG connections, leave the cable
shield’s drain wire insulated and disconnected at the M2A junction box.
You will connect the opposite end of the cable’s drain wire at the
controller or device.
• If the M2A will be wired into a Modbus network, see “Chapter 8: RS-485 Modbus
See Figure 8 below for field wiring connections to the M2A.
Figure 8: Wiring the M2A Junction Box to a Controller and Alarm Devices
3. 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.
4. Secure the M2A junction box cover to the junction box.
5. 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.
Alarm Device
Power
Typical Alarm
Wiring Shown
Fail Alarm
Device
Alarm 1
Alarm Device
RKI Controller
Terminals
(24 VDC) +
4 - 20 mA In (S)
(24 VDC) -
Alarm 2
Alarm Device
See
Modbus
Wiring
-
S
+
A
B
C
RS
4
8
5
PW
R
/S
IG
R
W
G
B
LE
L
See
Detector
Wiring
C
NC
NO
AL
A
R
M
1
C
NC
NO
AL
A
R
M
2
C
N
C
N
O
FA
IL
