RKI Instruments M2 for 12 VDC - Manual (Page 14)

9 M2 Transmitter Operator’s Manual, 12 V DC Operation
Wiring the M2 Transmitter
WARNING: Always verify that the power source is OFF before making any wiring
connections.
1. Remove the junction box cover.
2. Grasp the control PCB by its edges.
3. Gently pull until the control PCB is pulled away from the banana jacks. Take care not
to pull too hard and damage the cable which connects the control and terminal PCB’s.
4. Let the control PCB hang by the cable. The terminal strips are now visible on the
terminal PCB. The control PCB may be left hanging while wiring is done. If desired,
the control PCB may be disconnected from the cable and set aside while wiring.
5. The detector leads are factory wired. Verify that the detector leads are wired to the
detector terminal strip as shown below: Red wire to terminal labeled LEL R, white
wire to terminal labeled LEL W, green wire to terminal labeled LEL G, black wire to
terminal labeled LEL B.
Figure 4: LEL Detector Wiring
6. To gain access to a plug-in terminal strip for wiring, pull it out of its socket by
grasping the wall between two terminal positions with needle nose pliers and pulling.
Be careful not to exert too much force on the wall to avoid damage to the terminal
strip. The detector terminal strip and the alarm 1 relay terminal strip may be removed
by grasping them with you fingers if the adjacent terminal strips have been removed.
7. Guide multi conductor shielded cable or cables or wires in conduit through the top
conduit hub of the junction box. The number of cables or wires needed will depend on
whether the M2 is wired to a gas monitoring controller or just to power, whether any
relays are used, and whether the Modbus output is used.
NOTE: If the M2 is being wired to a PLC or DCS device, see “Appendix B: PLC and
DCS Device Wiring” on page 40, then continue with step 8.
Use the following recommendations to determine how to wire the M2:
• If Modbus connections will not be used and only the PWR/SIG connections will
C NC NO
C NC NO
C NC NO
ALARM 2
ALARM 1
F
AIL
A
B C RS 485
PWR/SIG
LEL
S
R W G B
Black
Green
White
Red
A
B C
RS 485
PWR/SIG
LEL
S
R W G B