Smoke Alarm User Manual
TWIST
COUNTERCLOCKWISE
TO REMOVE
DUCT
HOUSING
TWIST
CLOCKWISE
TO INSTALL
DETECTOR
HEAD
MOLDED RIB
TEST
MAGNET
PAINTED SIDE
TOWARD HOUSING
DUCT
DETECTOR
HOUSING
DETECTOR
HEAD
2. To determine that smoke is capable of entering the sens-
ing chamber, a visual examination should be conducted 
to note any obscurations around the sensing chamber. If 
a smoke test  is  required, smoke such as  cigarette,  cot-
ton wick, or punk smoke may be blown directly at the 
smoke detector head. It is important to plug the exhaust 
and sampling tube hole to prevent ducted air from blow-
ing smoke away from the smoke detector head. Record 
all test records in the Detector Test Log (page 12).
CAUTION
Remember to remove the plugs after this test or the detec-
tor will not sense smoke in the air duct.
7.2 Alarm Tests
Before  replacing  the  duct  housing  cover,  the  detector 
interconnections  should  be  checked.  The  DH500  may  be 
checked as follows:
A. M02-04-00 Magnet Test
  1. Make sure power is applied to the detector.
  2. Place the painted surface  of  the test magnet against 
the housing next to the rib molded onto the outside 
of the housing (see Figure 7).
  3. The LEDs on the detector should latch on as should 
any  accessories  (i.e.  RA400ZA,  RTS451),  and  the 
alarm condition  should be  verified at the  control 
panel.
Figure 7. Testing detector         
H0275-00
D500-08-00  7  I56-512-07R
Figure 8. Detector head removal:
H0276-00
B. RTS451/RTS451KEY Remote Test Station
The RTS451/RTS451KEY Remote Test Station facilitates test 
of the alarm capability of the duct detector as indicated in 
the RTS451/RTS451KEY manual. The DH500 duct detector 
cannot be reset by the RTS451/RTS451KEY. It must be reset 
at the system control panel.
To  install  the RTS451/RTS451KEY test  coil, connect  the 
device as shown in Figure 9; wire runs must be limited to 
25 ohms or less per interconnecting wire. Place the coil in 
the detector housing with the arrow facing up and pointing 
toward the detector as in Figure 9. Attach the coil leads to 
the housing terminals as shown; polarity is not important. 
Firmly screw the bracket in place over the test coil. 
7.3 MOD400 Sensitivity Test
After verification of alarm capability, the MOD400 test 
module  may  be  used  with  a  voltmeter  to  check  detector 
sensitivity as indicated in the MOD400 installation manual. 
The housing cover must be removed to perform this test.
If the MOD400 readings indicate that the detector head is 
outside of the acceptable range, the detector head requires 
cleaning. (See Periodic Maintenance Requirements on page 
9.)
7.4 Trouble Test
The capability of “TROUBLE” detection is tested by remov-
ing the detector head from the duct housing. The detector 
head  is  removed by turning  it  counterclockwise about 10 
degrees (Figure 8). The system control panel should indi-
cate a trouble condition. Reinserting the detector head 
should clear the trouble condition.










