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Chapter 7: Maintenance
M2A-XL Transmitter Operator’s Manual
8. Press and release the ENTER button. The M2A-XL will perform a zero operation. The display
will indicate
ZERO Gas PASS
for a few seconds, then indicate
ZERO Gas SAVED
before
indicating
Leaving CAL Mode
for a few seconds.
NOTE:
If the zero adjustment fails, see “Troubleshooting” on page 56 for
recommended actions.
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 M2A-XL will return to normal operation.
10. Store the components of the calibration kit in a safe place.
Replacing Components of the M2A-XL
Replacing the Gas Detector
NOTE:
For M2A-XL 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 M2A-XL 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 M2A-XL.
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 PCBs.
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.
