65-2670XL-XX-07 M2A-XL Transmitter
Chapter 3: Installation & Startup
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21
Wiring the M2A-XL to a Controller and Alarm Devices
1. Guide multi conductor shielded cable or cables or wires in conduit through the left conduit
hub of the M2A-XL junction box. The number of cables or wires needed will depend on
whether the M2A-XL is wired to a gas monitoring controller or just to power, whether any
relays are used, and whether the Modbus output is used.
WARNING: If the top conduit hub is used for wiring, be sure to seal the threads to ensure
water does not enter the junction box.
NOTE:
If the M2A-XL is being wired to a PLC or DCS device, see “Appendix B:
PLC and DCS Device Wiring” on page 62, then continue with step 8.
Use the following recommendations to determine how to wire the M2A-XL:
• If Modbus connections will not be used and only the PWR/SIG connections will be used,
use a two or three conductor shielded cable or two or three wires in conduit for
connections to the power/signal terminal strip depending on whether or not the signal (S)
terminal is used. The S terminal has a 4 - 20 mA output, but if you do not need to monitor
this signal and do not connect to the S terminal to access this signal, the M2A-XL will still
function completely.
• If the PWR/SIG connections and one or more relays are used, route the connections to the
M2A-XL 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-XL junction
box. You will connect the opposite end of the cable’s drain wire at the
controller or device.
• If the M2A-XL will be wired into a Modbus network, see “Chapter 8: RS-485 Modbus
Table 3: Wire Size for PWR/SIG Connections
Max Distance to
Controller
w/18 Gauge Wire
Max Distance to
Controller w/16
Gauge Wire
Max Distance to
Controller w/14 Gauge
Wire
2,500 ft.
5,000 ft.
8,000 ft.
