RKI Instruments 65-2485RK-02 - Manual (Page 20)

16 • 65-2485RK-02 Multi Point Detector
11. Calibrate the detector as described in “Calibration, H
2
S and CO Detectors” on
page 17.
Replacing the H
2
S Detector
NOTE: In most cases, it is only necessary to replace the H
2
S sensor.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Remove the junction box cover from the junction box.
4. Disconnect the detector leads from the terminal block in the junction box. Note the
position of the color-coded leads as you remove them.
5. Unscrew the detector from the junction box hub.
6. Guide the detector leads of the replacement detector through the junction box hub
then screw the mounting threads of the detector into the hub. If necessary for
environmental conditions, apply thread sealant or teflon tape to the hub and/or
detector threads to seal them.
7. Connect the detector leads to the terminal block the same way the old detector was
wired. See the controller operator’s manual and the controller’s detector head
specification sheet for the H
2
S detector to verify the connections are correct. Also see
Figure 5 for a wiring diagram.
8. Reinstall the junction box cover.
9. Turn on or plug in power to the controller.
10. Turn on the controller.
CAUTION: Allow the replacement detector to warm up for 5 minutes before you continue with
the next step.
11. Calibrate the replacement detector as described in “Calibration, H
2
S and CO
Detectors” on page 17.
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 months is adequate for most multi-point detector
applications. Unless experience in a particular application dictates otherwise, RKI
Instruments, Inc. recommends a calibration frequency of every 3 months for the multi-
point detector.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment, and calibration adjustments are minimal at calibration, then a
calibration frequency of every 6 months is adequate.
If an application is very demanding, for example if the environment is not well controlled,
then more frequent calibration than every 3 months may be necessary.