Maintenance
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17
Replacing the Amplifier
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Remove the junction box cover.
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
9. Install the detector and controller terminals strips into their sockets on the new amplifier as
shown in Figure 11 on page 12 of this manual. If controller leads or detector leads were
removed during this procedure, refer to Table 5 and Table 6 below.
Table 5: Reconnecting the Amplifier to the Controller
Amplifier
Controller
Terminal Strip
Controller
Transmitter Terminal
Strip (typical)
PWR/SIG “-”
- (DC -)
PWR/SIG “S”
S (4 - 20 mA In)
PWR/SIG “+”
+ 24V
Table 6: Reconnecting the LEL Detector to the Amplifier
Amplifier Detector
Terminal Strip
Detector Lead
DETECTOR “R”
RED
DETECTOR “W”
WHT
DETECTOR “G”
GREEN
DETECTOR “B”
BLK
