RKI Instruments M2 Series - Manual (Page 26)

21 M2 Transmitter Operator’s Manual
• ESM-01 Toxic Detectors
The ESM-01 toxic detectors have one black wire and one color coded wire. Connect the
color coded wire (see chart below) to the terminal labeled TOXIC + and the black wire to
the terminal labeled TOXIC -.
Figure 25: ESM-01 Toxic 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 your fingers if the adjacent terminal strips have been removed.
WARNING: If the M2 is installed in a hazardous location, use appropriately rated
conduit, conduit fittings, and appropriate construction technique that
complies with the local electrical code.
In addition, use appropriately rated conduit, conduit fittings, and
appropriate construction technique to maintain the NEMA 4
environmental rating of the junction box and avoid water entering the
junction box at the conduit hubs.
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 65, 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
be used, use a two or three conductor shielded cable or two or three wires in
C NC NO
C NC NO
C NC NO
ALARM 2
ALARM 1
F AIL
A B C
RS 485
PWR/SIG
S
T O
XIC O
X
Y
Black
A B C
RS 485
PWR/SIG
T O
XIC O
X
Y
S
See Chart
Wire Color Gas Type
Brown AsH3
Yellow Cl2
Red NH3
Orange NO
Green PH3
Blue SO2