RKI Instruments 65-2405RK-04 - Manual (Page 18)

14 • 65-2405RK-04 Combustible Gas Transmitter
4. Remove the detector junction box’s cover from the junction box.
5. Disconnect the detector leads from the terminal block in the detector junction box.
Note the position of the color-coded leads as you remove them.
6. Unscrew the detector from the detector junction box.
7. Guide the detector leads of the replacement detector through the bottom conduit hub
of the detector 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 terminal block the same way the old detector was
wired (see Figure 3 on page 7).
9. Screw the calibration cup/splash guard onto the new detector.
10. Reinstall the detector junction box cover.
11. Turn on or plug in power to the controller.
12. Turn on the controller and place it into normal operation.
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 combustible gas transmitter’s 4-20 mA signal should be
stable by the time the controller’s warmup period is over.
CAUTION: Allow the replacement detector to warm up for 5 minutes before you continue with
the next step.
13. Calibrate the transmitter as described in “Calibration” on page 17 of this manual.
Replacing the Amplifier
NOTE: The amplifier is not housed in the same junction box as the combustible gas
detector. The amplifier junction box should be somewhere accessible.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Remove the amplifier junction box’s cover from the junction box.
4. Unplug the detector terminal strip and controller terminal strip from their sockets.
You may leave the wires connected to the terminal strips.
5. Unscrew and remove the screw with the flat and lock washers that secures the
amplifier to the junction box.
6. Remove the old amplifier.
7. Place the new amplifier in the same position as the old amplifier. A foam gasket that
orients the amplifier and keeps it from rotating is installed on the bottom of the
amplifier. Make sure the amplifier is seated flat in the junction box.
8. Install the new amplifier into the junction box with the screw, lock washer, and flat
washer you removed in step 5 above.
9. Install the detector and controller terminals strips into their sockets on the new