65-2397SS CO
2
Transmitter • 17
NOTE:
When first powered up, the transmitter will enter about a one minute period when the 4-20
mA output is stabilizing and may be above the controller alarm points or well below zero
momentarily. RKI controllers have a one minute warmup period when the controller does not
display any gas reading or give any alarm indication. The CO
2
transmitter’s 4-20 mA signal
should be stable by the time the controller’s warmup period is over.
CAUTION:
Allow the replacement sensor to warm up for 5 minutes before you continue with the next
step.
9. Calibrate the transmitter as described in “Calibration” on page 20.
Replacing the IR CO
2
Detector
NOTE:
In most cases it is only necessary to replace the IR CO
2
plug-in sensor.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Remove the junction box cover.
4. Remove the detector terminal strip from its socket.
5. Disconnect the detector leads from the detector terminal strip. Note the position of the color-coded
leads as you remove them.
6. Unscrew the detector from the junction box.
7. Guide the detector leads of the replacement detector through the bottom conduit hub of the
junction box, then screw the mounting threads of the detector into the conduit hub. If necessary for
environmental conditions, apply thread sealant or Teflon tape to the hub and/or detector threads to
seal them.
8. Connect the detector leads to the detector terminal strip as shown in Table 3 below and Figure 5 on
page 12 of this manual.
9. Reinstall the detector terminal strip into its socket.
10. Reinstall the junction box cover.
11. Turn on or plug in power to the controller.
Table 3:Reconnecting the CO
2
Detector to the Amplifier
Detector Lead
Detector Terminal
Strip
Red
LEL “R”
White
LEL “W”
Green
LEL “G”
Black
LEL “B”
