System Sensor DH500 - Manual (Page 9)

D500-08-00 9 I56-512-07R
Recommended Detector Maintenance Procedure
NOTE: Notify the proper authorities that the smoke detec-
tor system is undergoing maintenance, and there-
fore the system will temporarily be out of service.
Disable the zone or system undergoing mainte-
nance to prevent unwanted alarms and possible
dispatch of the fire department.
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
reinstall the filters.
4. Remove detector from housing. (See Figure 8.)
Photo Units
5. Remove detector cover by inserting a small blade screw-
driver into the slot located 90 degrees from the MOD400
test jack receptacle, twisting the cover counterclockwise
to remove (see Figure 10).
6. Lift screen from photo chamber. Vacuum 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 photo chamber, then use clean compressed air
to blow area clean.
8. Replace screen by aligning arrow on top with the field
test slot on the base of the detector. Push screen into
place. Screen should fit tightly to chamber.
Ionization Units
9.
Remove the detector cover and screen assembly by
depressing the three lock prongs on the top of the cover
and rotating the cover counterclockwise. The CRT400
Cover Removal Tool makes cover removal easier. (See
Figure 11.)
10. Carefully pull the screen out of the cover.
11. Clean the screen thoroughly with a soft brush or vacu-
um (replacement screen available, part no. RS14).
12. Brush or vacuum the inside of the cover. Cover may
then be blown out using clean, compressed air. DO
NOT APPLY WATER TO THIS AREA.
13. Vacuum the sensing chamber before using clean, com-
pressed air to loosen and blow out any remaining
debris. DO NOT APPLY WATER TO THIS AREA.
14. Press the screen back into the cover.
15. Replace the detector cover and screen assembly on the
sensing chamber. Rotate it clockwise to lock it into
place.
Both Types Of Units
16. Reinstall the detector housing.
17. Restore power to the system.
REMOVABLE HEAD COVER
CLEANABLE SCREEN
HEAD COVER
REMOVAL SLOT
VANED CHAMBER
TEST SLOT
P/N RS24 (W/O THERMAL)
A78-1213-01
Figure 10. Photo head exploded view:
A78-1812-07
HOUSING
LOCK PRONGS
REMOVABLE SCREEN
(P/N RS14)
REMOVABLE
COVER
FOR
CLEANING
HEAD COVER
LOCK PRONGS
Figure 11. Ion head exploded view: