Carrier 48LC Series Service And Maintenance Instructions page 21

1. Disconnect power from the duct detector then remove
the sensor's cover. (See Fig. 28.)
Sampling
tube
Airflow
Fig. 28 - - Sensor Cleaning Diagram
2. Using a vacuum cleaner, clean compressed air, or a
soft bristle brush, remove loose dirt and debris from
inside the sensor housing and cover.
Use isopropyl alcohol and a lint- - free cloth to remove
dirt and other contaminants from the gasket on the
sensor's cover.
3. Squeeze the retainer clips on both sides of the optic
housing then lift the housing away from the printed
circuit board.
4. Gently remove dirt and debris from around the optic
plate and inside the optic housing.
5. Replace the optic housing and sensor cover.
6. Connect power to the duct detector then perform a
sensor alarm test.
Indicators
Normal State
The smoke detector operates in the normal state in the
absence of any trouble conditions and when its sensing
chamber is free of smoke. In the normal state, the Power
LED on both the sensor and the controller are on and all
other LEDs are off.
Alarm State
The smoke detector enters the alarm state when the
amount of smoke particulate in the sensor's sensing
chamber exceeds the alarm threshold value. (See Table 3.)
Upon entering the alarm state:
S The sensor's Alarm LED and the controller's Alarm
CONTROL OR INDICATOR
Magnetic test/reset switch
Alarm LED
Trouble LED
Dirty LED
Power LED
HVAC duct
Sensor
housing
Optic
plate
Retainer
clip
Optic
housing
C07305
Table 3 – Detector Indicators
Resets the sensor when it is in the alarm or trouble state. Activates or tests the sensor when it is in
the normal state.
Indicates the sensor is in the alarm state.
Indicates the sensor is in the trouble state.
Indicates the amount of environmental compensation used by the sensor
(flashing continuously = 100%)
Indicates the sensor is energized.
21
LED turn on.
S The contacts on the controller's two auxiliary relays
switch positions.
S The contacts on the controller's alarm initiation relay
close.
S The controller's remote alarm LED output is activated
(turned on).
S The controller's high impedance multiple fan shutdown
control line is pulled to ground Trouble state.
The SuperDuct duct smoke detector enters the trouble
state under the following conditions:
S A sensor's cover is removed and 20 minutes pass before
it is properly secured.
S A sensor's environmental compensation limit is reached
(100% dirty).
S A wiring fault between a sensor and the controller is
detected.
An internal sensor fault is detected upon entering the
trouble state:
S The contacts on the controller's supervisory relay
switch positions. (See Fig. 29.)
S If a sensor trouble, the sensor's Trouble LED the
controller's Trouble LED turn on.
S If 100% dirty, the sensor's Dirty LED turns on and the
controller's Trouble LED flashes continuously.
S If a wiring fault between a sensor and the controller, the
controller's Trouble LED turns on but not the sensor's.
Alarm
Fig. 29 - - Controller Assembly
NOTE: All troubles are latched by the duct smoke
detector. The trouble condition must be cleared and then
the duct smoke detector must be reset in order to restore it
to the normal state.
DESCRIPTION
Trouble
Power
Test/reset
switch
C07298