System Sensor DH500 User Manual
Page 2
D500-08-00
2
I56-512-07R
Note 1: The inlet sampling tube must be ordered separate-
ly. It must be the correct length for the width of the
duct where it will be installed. See Table 1 to deter-
mine the inlet tube required for different duct
widths. Smoke detector heads (1551, ionization;
2551, photoelectronic) must be ordered separately.
Installation Sequence
Page
Step 1. Verify duct air flow direction and velocity
2
Step 2. Drill the mounting holes
3
Step 3. Secure the housing base to the duct
3
Step 4. Install the inlet sampling tube
3
Step 5. Field wiring
5
Step 6. Install the filters and check pressure differential 5
Step 7. Perform detector check
7
Step 8. Install the cover
8
Step 9. Perform the final system check (Testing)
8
Step 1. Verify Duct Air Flow Direction and Velocity
The DH500 is designed to be used in air handling systems
having air velocities of 500 to 4000 feet per minute. Be sure
to check engineering specifications to ensure that the air
velocity in the duct falls within these parameters. If neces-
sary, an Alnor Model 6000-P velocity meter, Dwyer 460 dif-
ferential pressure gauge, or their equivalent, may be used
to check the air velocity in the duct.
A78-2093-00
SAMPLING TUBE
FILTERS
CONDUIT HOLES
DUCT DETECTOR
HOUSING
TERMINAL STRIP
DUCT DETECTOR
COVER
SAMPLING TUBE
MOUNTING
SCREWS
DETECTOR HEAD
(SUPPLIED SEPARATELY)
EXHAUST
FILTER ADAPTER
DETECTOR BASE
INLET SAMPLING TUBE
(SUPPLIED SEPARATELY)
O-RINGS
FOAM
GASKETS
HOUSING
MOUNTING SCREWS
TEST MAGNET
TUBE
END
PLUG
Figure 1:
Step 2. Drill the Mounting Holes
Remove the paper backing from the top and bottom of the
template. Affix the template to the air duct at the desired
mounting location. Make sure the template lies flat and
smooth on the air duct. Center punch hole targets and
remove the template. Drill the holes as indicated on the
template. Slide the two speed nuts over the two small holes
(Hole A) next to the sampling tube bushing holes (Hole B)
previously drilled in the duct. (See Figure 2.)
Step 3. Mount Duct Housing
Remove the duct housing cover. Slide the foam gaskets over
the tube bushings as shown in Figure 2B. Make sure the
two small holes in the gaskets line up with the two base
mounting holes. Put one 5/16-inch O-ring over each of the
two #10 sheet metal screws. Use the two sheet metal screws
to secure the duct housing to the duct.
Do not overtighten the screws.
CAUTION