35-3001A-07-03 Methane/Hydrogen Sulfide Sample-Draw Detector • 17
6. Remove the old amplifier from the main circuit board.
7. Install the new amplifier in the same orientation as the old amplifier. See Figure 1.
8. Reinstall the screw, lock washer, and flat washer you removed in step 5.
9. Install the detector and controller plug-in terminals strips into their sockets on the new
amplifier. If controller leads or detector cable leads were removed from the plug-in terminal
strips during this procedure, refer to Table 2 and Table 3 below.
NOTE:
When the sample-draw detector is first powered up with a new amplifier, the initial
output may be either high or below zero depending on the setting of the zero pot. Be sure
to make arrangements so that this does not cause unwanted alarms.
10. Turn on power to the controller.
11. Turn on the controller and place it into normal operation.
12. Allow the sample-draw detector to warmup for 5 minutes.
13. Calibrate the IR CH
4
sensor as described in “Calibration, IR CH
Replacing the H
2
S Sensor
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Unscrew the two screws in the upper right and lower left corners of the H
2
S flow block then
lift the H
2
S amplifier and sensor off of the flow block.
There is a gasket at the bottom of the flow block. Be sure the gasket stays in place.
5. Unplug the sensor from the H
2
S amplifier.
6. Verify that you are using the correct replacement sensor, then plug the sensor into the H
2
S
Table 2:Reconnecting the Amplifier
to the Detector/Amp Terminal Strip
Amplifier Controller
Terminal Strip
Detector/Amp Terminal
Strip on Main PCB
PWR/SIG “-”
-
PWR/SIG “S”
S
PWR/SIG “+”
+
Table 3:Reconnecting the IR Methane Sensor to the Amplifier
Amplifier Detector
Terminal Strip
Detector Lead
DETECTOR “R”
RED
DETECTOR “W”
WHT
DETECTOR “G”
GREEN
DETECTOR “B”
BLK
