[5] Duct Detector Maintenance And Test Procedures
Test and maintain duct detectors as recommended in NFPA
72. The tests contained in this manual were devised to
assist maintenance personnel in verification of proper
detector operation.
Before conducting these tests, notify the proper authorities
that the smoke detection system will be temporarily out of
service. Disable the zone or system under test to prevent
unwanted alarms.
After conducting these tests, record the appropriate infor-
mation in the Detector Test Log at the end of this manual.
[5.1] Smoke Entry Tests
[5.1.1] Air Flow
To verify sufficient sampling of ducted air, use a manom-
eter to measure the differential pressure created from air
flow across the sampling tubes. The pressure should mea-
sure no less than 0.01 inches of water and no greater than
1.20 inches of water.
[6.1.2] Smoke Response
To determine if smoke is capable of entering the sens-
ing chamber, visually identify any obstructions. Plug the
exhaust and inlet tube holes to prevent ducted air from
carrying smoke away from the detector head, then blow
smoke such as cigarette, cotton wick, or punk directly at
the head to cause an alarm. REMOVE THE PLUGS AFTER
TESTING OR THE DETECTOR WILL NOT FUNCTION
PROPERLY.
[6.1.3] Filter Replacement
The filters do not substantially affect smoke behavior even
when they are up to 90% clogged. Quarterly visual inspec-
tion is usually often enough to determine if filters should
be replace because only a high percentage of contamina-
tion affects duct detector performance.
Figure 9. Wiring diagrams for optional accessories (see Figure 7 for APA451 wiring diagram):
ALARM SIGNAL (+)
AUX POWER (–)
5
6
(+)
(–)
DUCT DETECTOR
DH400ACDC
PA400 (OPTIONAL)
AUDIBLE ALERT
ALARM SIGNAL (+)
AUX POWER (–)
5
6
(+)
(–)
DUCT DETECTOR
DH400ACDC
RA400Z (OPTIONAL)
REMOTE (LED)
ANNUNCIATOR
RED
ALARM SIGNAL (+)
AUX POWER (–)
5
6
1
2
DUCT DETECTOR
DH400ACDC
RTS451/RTS451KEY
(OPTIONAL) REMOTE
TEST STATION
R
E
D
5
3
4
3 RESET
TEST
4
FIELD
INSTALLED
JUMPER
RESET (–)
TEST (–)
H0242-00
[6.2] Standby, Alarm, And Sensitivity Tests
[6.2.1] Standby And Trouble
Standby- Check for the presence of the blinking red LEDs
(blinks about every 10 seconds) through the
housing cover. If the APA451 accessory is used,
its green Power LED should be illuminated con-
tinuously.
Trouble- If the detector LEDs do not blink or if the
APA451 Power LED is not illuminated, the detec-
tor lacks power (check wiring, panel, or power
supply), the head is missing (install), or the unit
is defective (return for repair).
Test- The trouble condition can be caused intention-
ally to verify correct operation of the system.
Remove power to the unit, remove the detec-
tor head (see Figure 11), or place the M02-04-
01 magnet into the Reset locator, as shown in
Figure 10. These actions should cause a trouble
condition locally and at the system control
panel.
D400-64-00 8 I56-991-08R
