System Sensor DH500ACDC - Manual (Page 2)

D500-07-00 2 I56-432-11R
The DH500ACDCs are built to operate on 120/240 VAC or
24 VAC/DC. Two form-C (SPDT) relay contacts are available
for control purposes. Two LEDs on each detector latch on
to provide a local alarm indication. Remote alarm indica-
tion is made possible by using the auxiliary alarm output
(see Figure 5). The duct detector can be tested and alarm
can be reset by using the correct respective code com-
mands from the panel. See panel instructions for details.
Contents Of The Duct Detector Housing Kit
The DH500ACDC Air Duct Detector Housings consist of the
following items: (See Figure 1.)
1. Complete housing base and cover assembly.
2. Two #10 sheet metal mounting screws.
3. Two sampling tube filters.
4. One test magnet.
5. Drilling template.
6. Two 5/16-inch O-rings.
7. Two foam gaskets.
8. Four #6 self-tapping mounting screws for the sampling
tube.
9. One filter adapter.
10. One inlet tube end plug.
11. Two #10 speed nuts.
Note 1: The inlet sampling tube must be ordered separately.
It must be the correct length for the width of the duct
where it will be installed. See Table 1 to determine
the inlet tube required for different duct widths. A
smoke detector head (1551 ionization or 2551 for
photoelectronic) must be ordered separately.
Figure 1:
SAMPLING TUBE
FILTERS
CONDUIT HOLES DUCT DETECTOR
HOUSING
PC BOARD
INSULATOR
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
A78-2448-00
Installation Sequence Page
Step 1. Verify duct air flow direction and velocity............2
Step 2. Drill the mounting holes .....................................2
Step 3. Mount duct housing ...........................................3
Step 4. Install the inlet tube ...........................................3
Step 5. Complete the field wiring....................................5
Step 6. Install the filters .................................................7
Step 7. Perform detector check .......................................7
Step 8. Install the cover..................................................9
Step 9. Perform the final system check (Testing)..............9
Step 1. Verify Duct Air Flow Direction And Velocity
The DH500ACDCA is designed to be used in air handling
systems having air velocities up to 500 feet per minute. Be
sure to check engineering specifications to ensure that the
air velocity in the duct falls within these parameters. If nec-
essary, use a velocity meter to check the air velocity in the
duct.
Step 2. Drill The Mounting Holes
Remove the paper backing from the drilling template. Affix
the template to the air duct at the desired mounting loca-
tion. 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.)
Location of detectors mounted in or on air ducts should be
at least six duct widths downstream from any duct open-
ings, deflection plates, sharp bends, or branch connections.
See Note 1 below for inlet
sampling tube and detector
supply information.