System Sensor D4240 User Manual
INSTALLATION AND MAINTENANCE INSTRUCTIONS
WARNING
3825 Ohio Avenue, St. Charles, Illinois 60174
D4240 Duct Smoke Detector
SPECIFICATIONS
Operating Temperature: D4240: –4° to 158° F (–20° to 70° C)
Storage Temperature: D4240: –22° to 158° F (–30° to 70° C)
Humidity: 0% to 95% Relative Humidity Non-condensing
Air Velocity: 100 to 4000 ft./min. (0.5 to 20.3 m/sec.)
D4240 Footprint Dimensions: Rectangular - 14.38 in L x 5 in W x 2.5 in D (37cm L x 12.7cm W x 6.36cm D)
Square - 7.75 in L x 9 in W x 2.5 in D (19.7cm L x 22.9cm W x 6.35cm D)
D4240 Weight: 2.5 pounds; 1.14 kg
Electrical
Power supply voltage: 20-29 VDC 24 VAC 50-60-Hz 240 VAC 50-60 Hz
Input capacitance: 270 µF max. 270 µF max. N/A
Reset Voltage: 3.0 VDC min. 2.0 VAC min. 20 VAC min.
Reset Time (with RTS451/RTS151): .03 to 0.3 sec. .03 to 0.3 sec. .03 to 0.3 sec.
Reset Time (by power down): 0.6 sec. max. 0.6 sec. max. 0.6 sec. max.
Power Up Time: 35 sec. max. 35 sec. max. 35 sec. max.
Alarm response time: 15 sec. 15 sec. 15 sec.
Sensitivity Test: See detector label See detector label See detector label
Current Requirements (Using No Accessories)
Max. standby current 21 mA @ 24 VDC 65 mA RMS @ 24VAC 60Hz 10 mA RMS @ 240 VAC 60 Hz
Max. alarm current 65 mA @ 24 VDC 135 mA RMS @ 24 VAC 60 Hz 18 mA RMS @ 240 VAC 60 Hz
1-800-SENSOR2, FAX: 630-377-6495
www.systemsensor.com
I56-3936-003R
CONTACT RATINGS
Alarm initiation contacts (SPST) 2.0A @ 30 VDC (resistive)
Alarm auxiliary contatcs (DPDT) 10A @30 VDC (resistive)
10A @250 VAC (resistive)
1
/2 HP @240 VAC
1
/4 HP @120 VAC
NOTE: Alarm auxiliary contacts shall not be connected to initiating circuits of
control panels. Use the alarm initiation contact for this purpose.
Supervisory Contacts (SPDT) 2.0A @ 30 VDC (resistive)
2.0A @ 125 VAC (resistive)
TABLE OF CONTENTS PAGE
[1] Limitations of Duct Smoke Detectors. . . . . . . . . . . . . . . . . . . . . . . . . . 1
[2]
Exploded View of Duct Smoke Detector Components
.............2
[3] General Description ......................................2
[4] Contents of Duct Smoke Detector Kit. . . . . . . . . . . . . . . . . . . . . . . . . . 2
[5] Detector Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
[6] Sampling Tube Installation .................................3
[7] Measurement Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
[8] Field Wiring Installation Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . 4
[9] Unit Configuration .......................................5
[10] Detector Status Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[11] Interconnection (Multiple Fan Shut Down). . . . . . . . . . . . . . . . . . . . . 6
[12] Verification of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[13] Detector Cleaning Procedures ..............................7
[14] Sensor replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
[15] Optional Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
BEFORE INSTALLING
Read the System Sensor Guide for Proper Use of Smoke Detectors in Duct
Applications (A05-1004), which provides information on detector spacing,
placement, zoning, wiring, and special applications. This manual is available
online at www.systemsensor.com. NFPA Standards 72 and 90A should also be
referenced for detailed information.
NOTICE: This manual shall be left with the owner/user of this equipment.
ACCESSORY CURRENT LOADS AT 24 VDC
DEVICE STANDBY TROUBLE ALARM
APA151/APA451 12.5mA n/a 30mA Max.
MHR/MHW 0mA n/a 29mA Max.
RA400Z/RA100Z 0mA n/a 12mA Max.
RTS451/RTS151 0mA n/a 12mA Max.
RTS451KEY/RTS151KEY 12mA n/a 12mA Max.
SSK451/RTS2-AOS 8mA Max. 16mA Max. 40mA Max.
NOTE: Any combination of accessories may be used such that the given
accessory loads are: 110mA or less at the Aux output, and 50mA or less
at the Alarm output.
IMPORTANT: This detector must be tested and maintained regularly following
NFPA 72 requirements. The detector should be cleaned at least once a year.
[1] LIMITATIONS OF DUCT SMOKE DETECTORS
The National Fire Protection Association has established that DUCT DETECTORS MUST NOT BE USED AS A SUBSTITUTE FOR OPEN AREA DETECTOR
PROTECTION as a means of providing life safety. Nor are they a substitute for
early warning in a building’s regular fire detection system.
System Sensor supports this position and strongly recommends that the user
read NFPA Standards 90A, 72, and 101. The D4240 Air Duct Smoke Detectors
are listed per UL 268A.
This device will not operate without electrical power. Fire situations may
cause an interruption of power. The system safeguards should be discussed
with your local fire protection specialist.
This device will not sense smoke unless the ventilation system is operating
and the cover is installed.
For this detector to function properly, it MUST be installed according to the instructions in this manual. Furthermore, the detector MUST be operated within
ALL electrical and environmental specifications listed in this manual. Failure
to comply with these requirements may prevent the detector from activating
when smoke is present in the air duct.
SS-300-022 1 I56-3936-003R
VARISTOR
[2] FIGURE 1. EXPLODED VIEW OF DUCT SMOKE DETECTOR COMPONENTS:
EXHAUST TUBE
METAL
SAMPLING TUBE
(sold seperately)
SENSOR HEAD
MAGNET TEST LOCATION
POWER BOARD
SENSOR MODULE
COVER
4-WIRE
POWER BOARD
MODULE COVER
H0549-11
[3] GENERAL DESCRIPTION
Smoke introduced into an air duct system will be distributed throughout the
entire building. Smoke detectors designed for use in air duct systems are used
to sense the presence of smoke in the duct.
Model D4240 Duct Smoke Detectors utilize 4-wire photoelectric technology
for the detection of smoke. This detection method, when combined with an
efficient housing, samples air passing through the duct allowing detection of
a developing hazardous condition. When sufficient smoke is sensed, an alarm
signal is initiated and appropriate action can be taken to shut off fans, blowers, change over air handling systems, etc. These actions can facilitate the
management of toxic smoke and fire gases throughout the areas served by the
duct system.
The D4240 detectors are designed to operate on 24 VDC/VAC or 240 VAC.
Alarm and supervisory relay contacts are available for control panel interface
(alarm initiation), HVAC control, and other auxiliary functions. Auxiliary relays are provided for fan shut down. Detector interconnection provides signaling of up to 50 other detectors in the loop for multiple fan shut down. These
detectors are not designed for 2-wire applications.
[3.1] DETECTOR FEATURE SET
-Utilizes 2D51 plug-in head
-2 sensors to 1 power board capability
-Cover missing signal
-Sampling tubes install from front or rear of detector
-Compatible with existing accessories
[4] CONTENTS OF THE DUCT SMOKE DETECTOR KIT
1. Sensor/power board assembly and cover(s)
2. Three #10 sheet metal screws for mounting
3. Drilling template
4. One sampling tube end cap
5. One plastic exhaust tube
NOTE: A sampling tube must be ordered to complete the installation. It must
be the correct length for the width of the duct where it will be installed.
See Table 1 on page 3 to determine the inlet tube required for different duct
widths.
[5] DETECTOR INSTALLATION
[5.1] VERIFY AIR FLOW DIRECTION AND VELOCITY
Model D4240 detectors are designed to be used in air handling systems with
air velocities of 100 to 4000 feet per minute. Duct widths from 6 inches to 12
feet can be accommodated. Be sure to check engineering specifications to
ensure that the air velocity in the duct falls within these parameters. If necessary, use a velocity meter (anemometer) to check the air velocity in the duct.
[5.2] DETERMINE MOUNTING LOCATION AND CONFIGURATION
On ducts wider than 18 inches it is recommended that the detector be
mounted downstream of a bend, obstruction in the duct, or the supply or
return air inlet.
Exception: Installation of duct detectors can be on or within a commercial
packaged rooftop heating and air-conditioning system, fire/smoke dampers
and economizers. They may be mounted in either the supply and/or return air
section as determined by local code.
Once a suitable location is selected, determine if the detector is to be mounted
in a side-by-side “rectangular” configuration or a top-over-bottom “square”
configuration as shown in Figure 2. If mounting in the square configuration,
remove the rear attachment screw, rotate the unit at the hinge, and replace the
screw into the new attachment hole as shown in Figure 2. Do NOT remove
the hinge screw during this process. Final installation approval shall be based
upon passing section 7.2.2 and/or 8.2.4 tests.
FIGURE 2:
REMOVE SCREW AND PIVOT
DETECTOR AS SHOWN BELOW.
REPLACE SCREW
TO SECURE DETECTOR
IN PLACE.
H0550-00
[5.3] DRILL THE MOUNTING HOLES
Remove the paper backing from the mounting template supplied. Affix the
template to the duct at the desired mounting location. Make sure the template
lies flat and smooth on the duct.
[5.3.1] FOR RECTANGULAR SIDE-BY-SIDE MOUNTING CONFIGURATION:
Center punch at (4) target centers: (2) “A” for sampling tubes and (2) “B” for
the rectangular configuration mounting tabs as shown on mounting template.
Drill pilot holes at target “A” centers and cut two 1.375 inch diameter holes
using a 13/8 inch hole saw or punch. Drill .156 inch diameter holes using a 5/32
inch drill at target “B” centers.
[5.3.2] FOR SQUARE TOP-OVER-BOTTOM MOUNTING
CONFIGURATION OR D4S SENSOR COMPONENT MOUNTING:
Center punch at (4) target centers: (2) “A” for sampling tubes and (2) “C” for
the square configuration mounting tabs as shown on mounting template. Drill
pilot holes at target “A” centers and cut two 1.375 inch diameter holes using
a 13/8 inch hole saw or punch. Drill .156 inch diameter holes using a 5/32 inch
drill at target “C” centers. If desired, drill an additional .156 inch hole at the
location of one of the mounting tabs on the lower housing.
[5.4] SECURE THE DUCT DETECTOR TO THE DUCT
Use two (rectangular configuration) or three (square configuration) of the provided sheet metal screws to screw the duct detector to the duct.
CAUTION: Do not overtighten the screws.
SS-300-022 2 I56-3936-003R
[6] SAMPLING TUBE INSTALLATION
SAMPLING TUBE ENDCAP
[6.1] SAMPLING TUBE SELECTION
The sampling tube must be purchased separately. Order the correct length,
as specified in Table 1, for width of the duct where it will be installed. It is
recommended that the sampling tube length extend at least 2/3 across the duct
width for optimal performance.
TABLE 1. SAMPLING TUBES RECOMMENDED FOR DIFFERENT
DUCT WIDTHS:
Outside Duct Width Sampling Tube Recommended*
Up to 1 ft. DST1
1 to 2 ft. DST1.5
2 to 4 ft. DST3
4 to 8 ft. DST5
8 to 12 ft. DST10 (2-piece)
*Must extend a minimum of 2/3 the duct width. These sampling tubes can
only be used with new InnovairFlex duct smoke detectors.
The sampling tube is always installed with the air inlet holes facing into the
air flow. To assist proper installation, the tube’s connector is marked with an
arrow. Make sure the sampling tube is mounted so that the arrow points into
the airflow as shown in Figure 3. Mounting the detector housing in a vertical
orientation is acceptable provided that the air flows directly into the sampling
tube holes as indicated in Figure 3. The sampling tube and exhaust tube
can be mounted in either housing connection as long as the exhaust tube is
mounted downstream from the sampling tube.
FIGURE 3. AIR DUCT DETECTOR SAMPLING TUBE:
ARROW MUST FACE
INTO AIR FLOW
AIR FLOW
DIRECTION
H0551-00
CAUTION: The sampling tube end cap, included with the detector, is critical to proper operation of the duct smoke detector. The end cap is needed to
create the proper air flow to the sensor of the duct smoke detector. Once any
sampling tube length adjustments are made, plug the end of the sampling tube
with the provided end cap.
A plastic exhaust tube is included with the unit to be installed if needed. Install into the housing connection that is downstream from the sampling tube
connection. The exhaust tube can be installed from the front or back of the
detector. A longer 1 foot exhaust tube, model ETX, is available as an accessory
in cases where the molded exhaust tube does not extend at least 2 inches into
the duct.
[6.2] SAMPLING TUBE INSTALLATION
1. For tubes shorter than the width of the duct, slide the sampling tube,
with installed end cap, into the housing connection that meets the airflow first. Position the tube so the arrow points into the airflow as shown
in Figure 3. Per NFPA sampling tubes over 3 feet long should be sup-
ported at the end opposite the duct detector. In ducts wider than 8 feet,
work must be performed inside the duct to couple the other section of
the sampling tube to the section already installed using the 1/2 inch conduit fitting. Make sure that the holes on both sections of the air inlet
sampling tube are lined up and facing into the airflow.
2. For tubes longer than the width of the duct, the tube should extend out
of the opposite side of the duct. Drill a 3/4 inch hole in the duct opposite
the hole already cut for the sampling tube. Ensure that the sampling tube
is angled downward from the duct smoke detector to allow for moisture
drainage away from the detector. The sampling tube should be angled
at least 1/4” downward for every 12” of duct width per Figure 4. There
should be 10 to 12 holes spaced as evenly as possible across the width of
the duct. If there are more than 2 holes in the section of the tube extend-
ing out of the duct, select a shorter tube using Table 1. Otherwise, trim
the tube to leave approximately 1 to 2 inches extending outside the duct.
Plug the end with the end cap and tape closed any holes in the protruding section of tube. Be sure to seal the duct where the tube protrudes.
FIGURE 4.
12˝
DETECTOR
H0215-00
2˝
3
/4˝
HOLE
1
/4˝
NOTE: Air currents inside the duct may cause excessive vibration, especially
when the longer sampling tubes are used. In these cases, a 3 inch floor flange
(available at most plumbing supply stores) may be used to fasten the sampling tube to the other side of the duct. When using the flange/connector
mounting technique, drill a 1 to 11/4 inch hole where the flange will be used.
[6.3] MODIFICATIONS OF SAMPLING TUBES
There may be applications where duct widths are not what is specified for the
installation. In such cases, it is permissible to modify a sampling tube that is
longer than necessary to span the duct width.
Use a 0.193 inch diameter (#10) drill and add the appropriate number of holes
so that the total number of holes exposed to the air flow in the duct is 10 to 12.
Space the additional holes as evenly as possible over the length of the tube.
NOTE: This procedure should only be used as a temporary fix and is not intended as a substitute for ordering the correct length tubes.
[6.4] REMOTE SAMPLING TUBE INSTALLATION
The detector arrangement can also incorporate remote mounting of the sampling tube and/or exhaust tube. In this case both the detector, sampling tube
and exhaust tube (if included) should be rigidly mounted to withstand the
pressure and vibrations caused by the air velocity. The location of the detector’s sampling tube should be such that there is uniform airflow in the cross
section area.
The pressure differential across the sampling and exhaust ports in the detector
housing shall be verified to be between 0.01 and 1.11 inches of water. Do so
by measuring the pressure difference between the inlet and outlet ports on the
detector housing using a manometer as described in Section 7.1.
[7] MEASUREMENT TESTS
[7.1] AIR FLOW
The D4240 is designed to operate over an extended air speed range of 100 to
4000 FPM. To verify sufficient sampling of ducted air, turn the air handler on
and use a manometer to measure the differential pressure between the two
sampling tubes. The differential pressure should measure at least 0.01 inches
of water and no more than 1.11 inches of water. Because most commercially
available manometers cannot accurately measure very low pressure differentials, applications with less than 500 FPM of air speed may require one of the
following: 1) the use of a current-sourcing pressure transmitter (Dwyer Series
607) per Section 7.2, or 2) the use of aerosol smoke per section 12.5.3.
[7.2] LOW FLOW AIR FLOW TEST USING DWYER SERIES 607
DIFFERENTIAL PRESSURE TRANSMITTER
Verify the air speed of the duct using an anemometer. Air speed must be at
least 100 FPM. Wire the Dwyer transmitter as shown in Figure 5. Connect the
leads of the meter to either side of the 1000Ω resistor. Allow unit to warm up
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 detector 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 measurement 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.
SS-300-022 3 I56-3936-003R
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