P/N: 3100686 REV: 2.0
18AUG05
Installation Sheet
2 / 3
SuperDuct Four-Wire Smoke Sensor (RJ-45 version)
Note:
In order to verify airflow direction and velocity, air must be
moving through the HVAC system.
Step 2: Drill the mounting holes
Attach the drill template to the HVAC duct. Drill (or punch) the
mounting holes where indicated. Remove any rough edges from the
holes.
Step 3: Assemble the sensor
Assemble the sensor as shown in Figure 1. Rotate the air sampling
tube so the inlet holes face the direction of airflow.
Note:
In some applications, it may be desirable to install the sampling
tube through the front of the sensor. For details, refer to Technical
Bulletin P/N 3100685.
Sensor
Sampling tube
socket
Exhaust tube
Thick
gasket
Thin
gasket
Exhaust tube
socket
Coupling
Sampling tube
(ordered separately)
Plug
Figure 1: Sensor assembly diagram
Sampling tubes must extend at least two-third across the width of the
duct and must be supported at the far end if longer than 36 inches.
Sampling tubes are available in the lengths listed below.
Model Description
SD-T8
8-inch sampling tube
SD-T18
18-inch sampling tube
SD-T24
24-inch sampling tube
SD-T36
36-inch sampling tube
SD-T42
42-inch sampling tube
SD-T60
60-inch sampling tube
SD-T78
78-inch sampling tube
SD-T120
120-inch sampling tube
Note:
For duct widths greater than 36 inches, use a sampling tube that
is longer than the width of the duct (see Figure 3).
Step 4: Mount the sensor
Mount the sensor to the HVAC duct as shown in Figure 2. Secure the
sensor using the two sheet metal screws provided in the hardware kit.
HVAC duct
Airflow
Sampling
tube
Sensor
#10 sheet metal screw (2X)
Figure 2: Sensor installation diagram
If the sampling tube is longer than the width of the duct, drill a 3/4-inch
hole on the opposite side of the duct. Extend the sampling tube
through the hole as shown in Figure 3 and seal all openings outside
the duct with an approved sealant.
HVAC
duct
Sampling
tube
Exhaust tube
Plug
Sensor
Sealant
Airflow
36 in
≥
Figure 3: Installation with sampling tubes longer than the width of the
duct
Step 5: Verify the air pressure differential
Open the sensor and connect a suitable air pressure differential meter
to the sampling tube and exhaust tube openings as shown in Figure 4.
Verify that the air pressure differential measured between the two
openings falls within the specified operating range of the sensor.
