System Sensor DH400ACDC, Installation And Maintenance Instructions Manual

of the alarm capability of the duct detector as indicated in
the RTS451/RTS451KEY manual. The DH400ACDC duct de-
tector can be reset by the RTS451/RTS451KEY. If a system
control panel is used, the panel itself may also require re-
setting.

To install the RTS451/RTS451KEY, connect the device as
shown in Figure 8; 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 12. Attach the coil leads to the hous-
ing terminals as shown; polarity is not important. Firmly
screw the bracket in place over the test coil.

[6.2.3] Sensitivity Tests

[6.2.3.1] MOD400R Sensitivity Test

After verification of alarm capability, use the MOD400R test
module with a voltmeter to check detector sensitivity as de-
scribed in the test module’s manual. The housing cover
must be removed to perform this test.

If test module readings indicate that the detector head is
outside of the acceptable range that is printed on the back
of the detector head, the detector head requires cleaning
per Section [7].

[6.2.3.2] R59-18-00 CALIBRATED TEST CARD (photo-

electronic units only)

After verification of alarm capability, the R59-18-00 test
card may be used to verify correct sensitivity of the detec-
tor head.
1. Remove the duct housing cover.
2. Remove the detector head from the housing as shown in

Figure 11.

3. Remove the detector head cover by placing a small blade

screwdriver in the side slot of the detector cover, twist-
ing it slightly until the cover can be turned counterclock-
wise.

DETECTOR

HEAD

TEST COIL

Figure 12. RTS451/RTS451KEY test coil installation:

A78-1994-02

4. Carefully reinsert the detector head into the duct hous-

ing and wait 50 seconds for power up. Do not hold the
swirl chamber to twist the detector head.

5. Insert the NO ALARM end of the test card into the test

slot (see Figure 13) and slide it counterclockwise until it
stops.  The detector should not alarm after 20 seconds.

6. Remove the card and then insert the ALARM end into

the slot and slide it counterclockwise until it stops. The
LEDs should latch on within 20 seconds. Remove card
and reset detector.

7. Put the cover back by gently rotating it clockwise until it

locks in place.  Secure the duct housing cover using the
4 cover screws.

[7] Detector Cleaning Procedures

Notify the proper authorities that the smoke detector sys-
tem is undergoing maintenance, and that the system will be
temporarily out of service. Disable the zone or system un-
dergoing maintenance to prevent unwanted alarms and
possible dispatch of the fire department.

[7.1] Air Filters

1. Turn off power to the system.
2. Remove and inspect the sampling tube filters.
3. If the 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.

[7.2] Photo Heads

1. Remove the detector cover by inserting a small bladed

screwdriver into the slot located 90 degrees from the
field test port. Rotate the cover counterclockwise to re-
move (see Figure 13).

2. 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

D400-13-00

10

I56-555-08