System Sensor DH500ACDC - Manual (Page 9)

Step 8. Install the Cover
Install the cover using the four screws. Be certain filters are
installed as specified in Step 6. Make sure that the cover fits
into the base groove and that all gaskets are in their prop-
er positions. Tighten the four cover screws to 10 in-lbs.
Step 9. Perform the Final System Check
Position the test magnet as shown in Figure 7. The LEDs on
the detector should light. Any accessory LED(s) should also
light and the system control panel should indicate an alarm
condition.
Periodic Maintenance Requirements
Air duct smoke detectors should be maintained at least
once a year – more often if the detector heads become obvi-
ously dirty. The detectors must also be cleaned immediate-
ly after a fire. Failure to properly maintain air duct smoke
detectors may cause unnecessary false alarms.
It is recommended that a permanent Detector Test Log be
set up and maintained, with a record for each individual
smoke detector in each building. Each detector should be
clearly described, with information on the type of detector,
the model number, the serial number (if any), the location,
and the type of environment. Data entries should include
test dates, type of test mode, test results, maintenance, and
comments. A Detector Test Log is included at the end of
this manual.
Recommended Detector Maintenance Procedure
NOTE: Notify the proper authorities that the smoke detec-
tor system is undergoing maintenance and will be
temporarily out of service. Disable the zone or sys-
tem undergoing maintenance to prevent unwanted
alarms and possible dispatch of the fire depart-
ment.
1. Turn off power to the system.
2. Remove and inspect sampling tube filters.
3. If filters are heavily coated with dirt, replace them with
new filters. If they are not heavily coated, use a vacuum
cleaner or compressed air nozzle to remove dust, then
install the filters.
4. Remove the detector from the housing. (See Figure 8.)
Photo Units
5. Remove the detector cover by inserting a small-bladed
screwdriver into the slot located approximately 90
degrees from the MOD400 test jack. Rotate the cover
counterclockwise to remove it. See Figure 10.
6. Lift the screen from the photo chamber. Vacuum the
screen and cover before using clean, compressed air to
loosen and blow out any remaining debris (replacement
screens are available, part no. RS24).
7. Vacuum the photo chamber. Then, use clean compressed
air to blow it clean.
8. Replace the screen by aligning the arrow on top with the
test slot in the base of the detector. Press the screen into
place. It should fit tightly in the chamber.
Figure 10. Photo head exploded view:
LOCK PRONG
REMOVABLE SCREEN
(P/N RS14)
REMOVABLE
COVER
FOR
CLEANING
SENSING CHAMBER
A78-2340-00
Figure 11. Ion head, exploded view:
REMOVABLE HEAD COVER
REMOVABLE SCREEN
HEAD COVER
REMOVAL SLOT
VANED CHAMBER
(P/N RS24)
A78-2392-00
D500-07-00 9 I56-432-11R