background image

Exception:  Installation  of  duct  detectors  can  be  on  or  within  a  commercial 
packaged  rooftop  heating  and  air-conditioning  system,  fire/smoke  dampers 
and economizers. They may be mounted in either the supply and/or return air 
section as determined by local code.

Once a suitable location is selected, determine if the detector is to be mounted 
in  a  side-by-side  “rectangular”  configuration  or  a  top-over-bottom  “square” 
configuration as shown in Figure 2. If mounting in the square configuration, 
remove the rear attachment screw, rotate the unit at hinge, and replace the 
screw into the new attachment hole as shown in Figure 2. Do NOT remove 
the hinge screw during this process. Final installation approval shall be based 
upon passing differential pressure and smoke entry tests described in the Mea-
surement Tests section.

fIgURE 2:

REMOVE SCREW AND PIVOT

DETECTOR AS SHOWN BELOW.

REPLACE SCREW

TO SECURE DETECTOR

IN PLACE.

H0550-00

[4.3]DRILL ThE MOUNTINg hOLES

Remove  the  paper  backing  from  the  mounting  template  supplied.  Affix  the 
template to the duct at the desired mounting location. Make sure the template 
lies flat and smooth on the duct. 

[4.3.1]fOR RECTANgULAR SIDE-By-SIDE MOUNTINg CONfIgURATION:

Center punch at (4) target centers: (2) “A” for sampling tubes and (2) “B” for 
the rectangular configuration mounting tabs as shown on mounting template. 
Drill pilot holes at target “A” centers and cut two 1.375 inch diameter holes 
using a 1

3

8

-inch hole saw or punch. Drill .156 inch diameter holes using a 

5

32

 

inch drill at target “B” centers.

[4.3.2]fOR SqUARE TOP-OVER-BOTTOM MOUNTINg CONfIgURATION:

Center punch at (4) target centers: (2) “A” for sampling tubes and (2) “C” for 
the square configuration mounting tabs as shown on mounting template. Drill 
pilot holes at target “A” centers and cut two 1.375 inch diameter holes using 
a 1

3

8

-inch hole saw or punch. Drill .156 inch diameter holes using a 

5

32

 inch 

drill at target “C” centers. If desired, drill an additional .156 inch hole at the 
location of one of the mounting tabs on the lower housing.

[4.4]SECURE ThE DUCT DETECTOR TO ThE DUCT

Use two (rectangular configuration) or three (square configuration) of the pro-
vided sheet metal screws to screw the duct detector to the duct.

CAUTION: Do not overtighten the screws.

[5]SAMPLINg TUBE INSTALLATION 
[5.1]SAMPLINg TUBE SELECTION

The  sampling  tube  must  be  purchased  separately.  Order  the  correct  length, 
as specified in Table 1, for width of the duct where it will be installed. The 
sampling tube length must extend at least 

2

/

3

 across the duct width for optimal 

performance.

The sampling tube is always installed with the air inlet holes facing into the 
air flow. To assist proper installation, the tube’s connector is marked with an 
arrow. Make sure the sampling tube is mounted so that the arrow points into 
the airflow as shown in Figure 3. Mounting the detector housing in a vertical 
orientation  is  acceptable  provided  that  the  air  flows  directly  into  the  sam-
pling tube holes as indicated in Figure 3. The sampling tube and exhaust tube 
can be mounted in either housing connection as long as the exhaust tube is 
mounted downstream from the sampling tube.

TABLE 1. SAMPLINg TUBES RECOMMENDED fOR 
DIffERENT DUCT wIDThS:

Outside Duct Width

Sampling Tube Recommended*

Up to 1 ft.

DST1

1 to 2 ft.

DST1.5

2 to 4 ft.

DST3

4 to 8 ft.

DST5

8 to 12 ft.

DST10 (2-piece)

*Must extend a minimum of 

2

3

 the duct width

fIgURE 3. AIR DUCT DETECTOR SAMPLINg TUBE:

SAMPLING TUBE ENDCAP

ARROW MUST FACE 

INTO AIR FLOW

AIR FLOW 

DIRECTION

FL-300-000 

I56-3255-003R

fIgURE 1. ExPLODED VIEw Of DUCT SMOkE DETECTOR COMPONENTS:

H0569-02

EXHAUST TUBE

SENSOR HEAD

SENSOR MODULE COVER

WIRING COMPARTMENT COVER

WIRING COMPARTMENT

SENSOR MODULE

SAMPLING 

TUBE

SOLD 

SEPERATELY

H0551-00

Summary of Contents for D355PL

Page 1: ...e fire control panel monitoring the detector and appropriate action can be taken to shut off fans blowers change over air handling systems etc These actions can facilitate the management of toxic smoke and fire gases throughout the areas served by the duct system The D355PL incorporates a sensor cover tamper feature that provides a trou ble signal at the panel immediately if the cover is removed o...

Page 2: ...ers and cut two 1 375 inch diameter holes using a 13 8 inch hole saw or punch Drill 156 inch diameter holes using a 5 32 inch drill at target C centers If desired drill an additional 156 inch hole at the location of one of the mounting tabs on the lower housing 4 4 Secure the Duct Detector to the Duct Use two rectangular configuration or three square configuration of the pro vided sheet metal scre...

Page 3: ...the housing connection that meets the air flow first Position the tube so that the arrow points into the airflow as shown in Figure 3 Per NFPA sampling tubes over 3 feet long should be supported at the end opposite of the duct detector In ducts wider than 8 feet work must be performed inside the duct to couple the other section of the sampling tube to the section already installed using the inch c...

Page 4: ... service Disable the zone or system undergoing maintenance to prevent unwanted alarms and possible dispatch of the fire department 9 1 Detector Sensor 1 Remove the sensor to be cleaned from the system 2 Remove the sensor cover by pressing firmly on each of the four removal tabs that hold the cover in place 3 Vacuum the screen carefully without removing it If further cleaning is re quired continue ...

Reviews: