Replacing components of the m2 – RKI Instruments M2 Series User Manual
Page 51

M2 Transmitter Operator’s Manual
46
9.
The display will now alternate between the normal operation screen and the message
REMOVE CAL GAS
for 1 minute. If the calibration gas has not been removed from
the detector remove it now to avoid unwanted alarms.
During this 1 minute period, the signal output will remain fixed at 17.4 mA and the
relays will remain in their non-alarm state to avoid unwanted alarms while the
calibration gas clears from the detector. At the end of the 1 minute period, the
REMOVE CAL GAS
message will stop appearing and the M2 will return to normal
operation.
10. Store the components of the calibration kit in a safe place.
Replacing Components of the M2
Replacing the Gas Detector
NOTE:
For M2 versions that do not have a replaceable plug-in sensor, or if you
determine that it is necessary to replace the entire detector, use the procedure in
this section to change the entire detector. For M2 versions that include a
replaceable plug-in sensor, see the appropriate instructions in the sections that
follow this one to replace the plug-in sensor.
1.
Turn off or disconnect power to the M2.
2.
Remove the junction box cover.
3.
Grasp the control PCB by its edges.
4.
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.
5.
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.
6.
Remove the detector terminal strip from its socket.
7.
Disconnect the detector leads from the detector terminal strip. Note the position of the
color-coded leads as you remove them.
8.
Unscrew the detector from the junction box.
9.
Guide the replacement detector leads through the bottom conduit hub of the junction
box, then screw the mounting threads of the detector into the conduit hub.
10. Connect the detector leads to the detector terminal strip as follows:
•
Catalytic Combustible Gas Detector, IR Combustible Gas Detector, and IR CO
2
Detector
Red wire to terminal labeled LEL RED, white to terminal labeled LEL WHT, green
wire to terminal labeled LEL GRN, black wire to terminal labeled LEL BLK.
•
CO or H2S gas detector.
Red wire to terminal labeled TOXIC +, black wire to terminal labeled TOXIC -.
•
ESM-01 Gas Detector
Color coded wire to terminal labeled TOXIC +, black wire to terminal labeled
TOXIC -. See Figure 25, “ESM-01 Toxic Detector Wiring” on page 21 for the wire
color coding.