System Sensor DNRHS - Manual (Page 4)

SS-400-006 4 I56-3535-002R
for 15 seconds . With both HIGH and LOW pressure ports open to ambient air,
measure and record the voltage drop across the 1000Ω resistor (measurement
1), 4 .00 volts is typical . Using flexible tubing and rubber stoppers, connect the
HIGH side of the transmitter to the sampling tube of the duct smoke detec-
tor housing, and the LOW side of the transmitter to the exhaust tube of the
duct smoke detector housing . Measure and record the voltage drop across the
1000Ω resistor (measurement 2) . Subtract the voltage recorded in measure-
ment 1 from the voltage recorded in measurement 2 . If the difference is greater
than 0 .15 volts, there is enough air flow through the duct smoke detector for
proper operation .
[7]fIELD wIRInG; InSTaLLaTIOn GuIDELInES
All wiring must be installed in compliance with the National Electrical Code
and the local codes having jurisdiction . Proper wire gauges should be used .
The conductors used to connect smoke detectors to control panels and acces-
sory devices should be color-coded to prevent wiring mistakes . Improper con-
nections can prevent a system from responding properly in the event of a fire .
For signal wiring (the wiring between detectors or from detector to auxiliary
devices), it is usually recommended that single conductor wire be no smaller
than 18 gauge . The duct smoke detector terminals accommodate wire sizes up
to 12 gauge . Flexible conduit is recommended for the last foot of conduit; solid
conduit connections may be used if desired .
Duct smoke detectors and alarm system control panels have specifications for
Signaling Line Circuit (SLC) wiring . Consult the control panel manufacturer’s
specifications for wiring requirements before wiring the detector loop .
[7.1]wIRInG InSTRuCTIOnS
Disconnect power from the communication line before installing the DNRHS
duct smoke detector .
The DNRHS detectors are designed for easy wiring . The housing provides a
terminal strip with clamping plates . Wiring connections are made by sliding
the bare end under the plate, and tightening the clamping plate screw . See
Figure 7 below for system wiring .
[7.2] SET THE aDDRESS
Set the desired address on the sensor head code wheel switches . on the back
of the sensor head .
.fIGuRE 8. ROTaRy aDDRESS SwITCHES
[8] VERIfICaTIOn Of OPERaTIOn
[8.1]InSTaLL THE COVER
Install the covers making sure that the cover fits into the base groove . Tighten
the screws that are captured in the covers . Note that the cover must be prop-
erly installed for proper operation of the sensor .
[8.2] POwER THE unIT
Activate the communication line on terminals COM + and COM – .
[8.3] DETECTOR CHECk
Standby – If programmed by the system control panel, look for the presence of
the flashing LEDs through the transparent housing cover . The LED will flash
with each communication .
Trouble – If programmed by the system control panel and the detector LEDs
do not flash, then the detector lacks power (check wiring, missing or improp-
erly placed cover, panel programming, or power supply), the sensor head is
missing (replace), or the unit is defective (return for repair) .
[8.4]DuCT SmOkE DETECTOR TEST & maInTEnanCE PROCEDuRES
Test and maintain duct smoke 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 .
[8.4.1]TEST THE unIT
1 . M02-04-00 Magnet Test (not included) – This sensor can be function-
ally tested with a test magnet . The test magnet electronically simulates
smoke in the sensing chamber, testing the sensor electronics and connec-
tions to the control panel .
2 . Remote Test Accessory – The use of a remote accessory for visible indica-
tion of power and alarm is recommended .
Verify system control panel alarm status and control panel execution of
all intended auxiliary functions (i .e . fan shutdown, damper control, etc .) .
Two LEDs on the sensor are controlled by the panel to indicate sensor
status . Coded signals, transmitted from the panel, can cause the LEDs
to blink, latch on, or latch off . Refer to the control panel technical docu-
mentation for sensor LED operation and expected delay to alarm .
[8.4.2] THE DETECTOR muST BE RESET By THE SySTEm COnTROL PanEL
[8.4.3]SmOkE EnTRy TEST uSInG aEROSOL SmOkE
This test is intended for low-flow systems (<500 FPM) . If the air speed is
greater than 500 FPM, use a conventional manometer to measure differential
pressure between the sampling tubes, as described under Measurement Tests
on Page 3 .
The detectors must also be cleaned immediately after a fire (see cleaning sec-
tion) . Failure to properly maintain air duct smoke detectors may cause unnec-
essary false alarms .
It is recommended that a permanent Detector Test Log be set up and main-
tained, 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 in
this manual .
Drill a ¼-inch hole 3 feet upstream from the duct smoke detector . With the air
handler on, measure the air velocity with an anemometer . Air speed must be
at least 300 FPM . Spray aerosol smoke* into the duct through the ¼-inch hole
for five seconds . Wait two minutes for the duct smoke detector to alarm . If the
duct smoke detector alarms, air is flowing through the detector . Remove the
duct smoke detector cover and blow out the residual aerosol smoke from the
chamber and reset the duct smoke detector at the panel . Use duct tape to seal
the aerosol smoke entry hole . Remember to replace the cover after the test or
the detector will not function properly .
*Aerosol smoke can be purchased from Home Safeguard Industries at home-
safeguard .com, model 25S Smoke Detector Tester, and Chekkit Smoke De-
tector Tester model CHEK02 and CHEK06 available from SDi . When used
properly, the canned smoke agent will cause the smoke detector to go into
alarm . Refer to the manufacturer’s published instructions for proper use of the
canned smoke agent .
CO146-00
fIGuRE 7. SySTEm wIRInG DIaGRam fOR DnRHS:
HO572-00
COMM.
LINE (+)
UL/FM LISTED
CONTROL
PANEL
1ST
DETECTOR
IN LOOP
2ND
DETECTOR
IN LOOP
COMM.
LINE (–)
COMM.
LINE
TENS ONES
9
8 7
6
5
4
3
2
1 0
9
8 7
6
5
4
3
2
1 0