Specifications | Bosch Power Tools DS241 Speaker System User Manual

Installation Instructions
DS240 and DS241
Long Range Beam Smoke Detectors
The DS240 and DS241 are long range projected beam type smoke
detectors which consist of a separate transmitter and receiver. Internal
pointability provides coverage flexibility without the need for brackets.
Automatic Signal Synchronization and Range Adjustment reduce
installation costs. Selectable sensitivity and alarm response time
provide installation flexibility.
• Listings and
• Operating Voltage: DS240: 18.0 VDC to 32.0 VDC
DS241: 10.2 VDC to 15.0 VDC
• Standby Current: DS240: Receiver: 45 mA @ 24.0 VDC
Transmitter: 20 mA @ 24.0 VDC
DS241: Receiver: 50 mA @ 12.0 VDC
Transmitter: 20 mA @ 12.0 VDC
• Receiver Alarm
DS240: 60 mA @ 24.0 VDC
DS241: 75 mA @ 12.0 VDC
• Range (distance
between transmitter
and receiver):
30 ft to 350 ft (9 m to 107 m)
• Spacing (distance
between systems): Allow no more than 60 ft (18 m) between
systems. Sixty foot spacing is confirmed
by Underwriters Laboratories, Inc. testing.
• Pointability:
Internally pointable optics for ±90°
horizontal, and ±10° vertical adjustment.
• Sensitivity:
Field selectable for 20, 30, 40, 50, 60, or
70 percent beam obscuration.
• Alarm Contacts:
Normally Open contacts rated 1 A,
60 VDC maximum for DC resistive loads.
Do not use with capacitive or inductive
• Trouble Contacts: Normally Closed contacts rated 1 A, 60 VDC
maximum for DC resistive loads. Do not
use with capacitive or inductive loads.
• Aux. Alarm
Form "C" (NO, C, NC) contacts rated 1 A,
60 VDC maximum for DC resistive loads.
Do not use with capacitive or inductive
• Tamper:
Access door tamper switch in
series with trouble contacts.
Transmitter: Upon cover’s removal, cover
tamper switch interrupts
• System Signaling: Conventional 4-wire system. Not for use
with systems that incorporate an alarm
verification feature.
• Signal Delay:
Selectable 30 sec or 5 sec
20 ± 2 sec
• Temperature:
The storage and operating temperature
range is -22°F to +130°F (-30°C to +54°C).
For UL Listed installations, the range is
+32°F to +130°F (0°C to +54°C).
• Mounting:
The units are designed to be mounted to
4 in. (10 cm) square or octagonal
electrical boxes (not supplied).
Downloaded from: http://www.guardianalarms.net
• Standard
• Options:
Permit #1943
Acceptance #MEA274-93-E
Job #OX2A9.AY
DIS2000 Remote Test/Indicator Plate and
Test Cable
DIS240 Remote Indicator Plate, TK240
Field Test Kit, AL240 Alignment Light, and
TC2000 Test Cord.
Principle of Operation
Each DS240 or DS241 beam smoke detector has a separate
transmitter and receiver. The transmitter transmits an invisible infrared
beam of a specific frequency and intensity. The receiver detects, then
measures the beam’s intensity (see Figure 1).
Figure 1 - Infrared Transmission
As the beam is obscured by smoke, the receiver senses a decrease
in the signal strength and measures that decrease. The receiver
compares the signal level with two preset thresholds: an alarm
threshold which is set using the sensitivity switch and a trouble
threshold which is preset at approximately 10%. If the signal falls
below the alarm threshold for the programmed alarm period, the
receiver signals an alarm (see Figure 2).
Figure 2 - Beam Obscuration
If the signal falls below the trouble threshold for more than 20 sec,
such as might happen if the beam is blocked by a foreign object, the
receiver signals a trouble condition (see Figure 3).
Figure 3 - Beam Blockage
The receiver automatically compensates for the gradual loss of signal
due to dust/dirt build-up on the cover. After 50 percent of the signal is
lost, the receiver will indicate a trouble. When the dust/dirt build-up is
cleaned or the blockage is removed, the detector automatically goes
back to its normal operation level.
A trouble will be indicated at the receiver if the beam strength is
increased by more than 20% for greater than 20 sec. Causes include
improper initial alignment or the removal of a partial beam blockage
at the time of alignment. Preform a fine-tune alignment (see Section
7.3 Fine Tune Alignment on page 6).
4.2 Avoid sources of bright light
Installation Considerations
The proper location and spacing of detectors is critical in a properly
installed and operating fire alarm system. For best results, it is
recommended that the detectors be located and spaced in
accordance with the National Fire Protection Association (NFPA)
Standard 72 "The National Fire Code.” This standard is available at a
nominal cost from The National Fire Protection Association,
Batterymarch Park, Quincy, MA, 02269.
In all installations, good engineering judgement should prevail. The
following are some general considerations:
Sunlight and light from extremely bright sources such as the exposed
bulbs of high pressure sodium, mercury vapor, and metal halide
lights can cause stray signals. The receiver should not be pointed
toward any of these sources.
Sunlight: Avoid pointing the receiver directly at the rising or setting
sun. If you are installing the unit where sunlight can’t be avoided,
mount the receiver slightly higher than the transmitter and aimed
down toward the transmitter. This should reduce this problem by
causing the receiver to look below the horizon.
Bright Lights: Don’t mount the receiver where it is looking at exposed
bulbs of high pressure sodium, mercury vapor, and metal halide
lights. The illustration below shows where these exposed lights
should be avoided.
• Do not use mirrors. The detectors should be installed with a
clear line-of-sight between the transmitter and receiver.
• The beam path should be clear of moving objects.
• Set the sensitivity based on the distance between the transmitter
and receiver. See Section 7.2 Sensitivity Adjustment on page 5.
Keep bright lights out of this area
4.5 ft. (1.4 m)
14.5 ft.
(4.4 m)
225 ft. (68.6 m)
• The detectors may be mounted directly to the ceiling or to side
walls. Do not mount the units where the beam path may run
parallel within 4 in. (10.2 cm) of a corner.
• For a sloped or peaked ceiling, the beam path should be located
within 3 ft (1 m) of the ceiling’s peak.
350 ft. (106.8 m)
Bare fluorescent lights may also pose a problem especially in long
hallways where a series of lights run perpendicular to the beam.
Incandescent lights are not a problem as long as they are not directly
in the beam path.
4.3 Use the correct wire gauge and length
• Stratification of air may hinder smoke from reaching detectors
mounted close to the ceiling. Stratification occurs when smoke,
rising because it is warmer than the surrounding air, reaches a
level where it is the same temperature as the surrounding air
and will not rise to the ceiling. If stratification is considered a
possibility, extra beams should be installed where stratification
is expected.
Beam smoke detectors are often used to protect very large areas.
This means that the wire runs used to power the detectors and signal
alarm conditions can be very long. The voltage available at the end of
very long wire runs may not be sufficient to power the detector,
especially when the system is running on battery backup. It is very
important that the correct wire gauge is used for these installations.
• Avoid areas subject to normal smoke concentrations such as
kitchens and garages.
Use the following chart to determine the proper wire size, wire length
and the number of transmitter and receiver pairs that can be used.
• Do not install units where normal ambient temperatures are
below -22°F (-30°C) or above +130°F (+54°C).
Wire Siz e
The following are some specific installation considerations:
4.1 Avoid Sources of Heat and Air Movement
The detectors should be located where the beam path will not pass
near heating and cooling outlets.
• Don’t mount where hot or cold air can blow directly into the beam
• Heating, ventilating, and air conditioning systems can cause
smoke to be blown away from the beam path.
500 ft (152 m)
1000 ft (304 m)
2500 ft (762 m)
5000 ft (1524 m)
14 AWG
(1.8 mm)
16 AWG
(1.5 mm)
18 AWG
(1.2 mm)
20 pairs
10 pairs
4 pairs
2 pairs
13 pairs
6 pairs
3 pairs
1 pai r
8 pairs
4 pairs
2 pairs
1 pai r
- Smoke must accumulate in the beam path to be detected.
• Heaters mounted close to the beam path can cause the beam to
become distorted.
You can test for beam distortion by monitoring the signal voltage.
After setup, the signal voltage of the detector should read 4 VDC.
Monitor the voltage and turn on all heating and cooling devices in the
area. The signal voltage should not fluctuate more than 0.20 VDC. If
it does, the detector should be moved to avoid these disturbances.
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P/N: 22066P
© 2004 Bosch
DS240/DS241 Installation Instructions
4.4 Provide a stable mounting surface
4.6 Consider the expected Fire load
Beam smoke detectors depend on the measurement of the projected
beam to sense smoke. Therefore, shifts in the alignment of the beam
due to movement of the transmitter/receiver can cause trouble or
alarm conditions.
When designing a fire alarm system, consider the expected fire load
within the application.
• Always select a stable mounting surface.
• Never mount the unit to a suspended support such as a pipe or
length of wood supported at only one end.
For instance, fires caused by the ignition of flammable petroleumbased liquids usually result in a rapid buildup of heavy smoke. When
these types of fires are probable, use sensitivity settings 0 or 1 which
provide a response time of 5 sec.
This type of mounting can create a “pendulum effect” which greatly
multiplies even very small movements at one end of the support. For
example, a 2 in. (5.1 cm) movement translates into a beam
misalignment of over 20 ft at 350 ft (6 m at 107 m).
NOTE: This product is not designed for use in outdoor applications.
Mounting surfaces should be supported at opposite corners to reduce
the pendulum effect.
NOTE: If not mounting to an electrical box, be sure the surface will
not be subject to movement or vibrations. For example: do
not mount directly to a suspended ceiling without extra
• Always select surfaces not subject to building movement.
The automatic compensation circuits of the DS240 and DS241 will
eliminate most problems created by normal building expansions
and contractions. In some unusual circumstances, the walls and
support structure may be subject to more significant movement due
to the operation of heavy equipment, such as cranes, anchored to the
top of the walls.
When in doubt about mounting surface stability, measure the signal
voltage of the detector. This voltage should be 4.0 VDC. Misalignment
of the beam can cause this voltage to increase or decrease. The
detector will indicate a trouble condition when the voltage increases
to more than 4.8 VDC, or when it decreases to less than 2.0 VDC over
a long period of time or to 0.4 VDC greater than 20 sec. For more
information on reading this voltage, see Section 8.3 Reference
Voltage Calibration on page 6).
If movement of the mounting surface is suspected, relocate the
detector to a surface that does not move or add supports to the
mounting surface to prohibit movement.
Install a 4 in. (10 cm) square or octagonal electrical box (not supplied)
to a rigid surface that will not be subject to movement or vibrations.
• Remove the receiver's access door (1 screw), then remove the
cover (4 screws). See Figure 4.
Figure 4 - Access Door and Cover
• Remove the receiver’s backplate by removing the single
mounting screw from the top of the circuit board carrier plate then
separating the two plates (see Figure 5).
• DO NOT over-tighten the mounting screws.
When the detector is mounted to an electrical mounting box
[4 in. (10 cm) square or octagonal], the mounting plate may bow as a
result of the mounting box screw tabs being below flush with the top
edges of the mounting box. Over-tightening the mounting screws
bows the mounting plate inward at the bottom, causing the optics to
aim low.
Irregularities in the flatness of the mounting box edge surfaces or
screw tabs will worsen this condition. Using only mounting boxes
with flat, regular surfaces and properly formed screw tabs, and
tightening the mounting screws to secure the mounting plate to
2 in./lb torque will minimize any misalignment caused by bowing of
the mounting plate.
4.5 Consider the effects of stratification in cold environments
In very cold environments such as unheated warehouses, smoke
may cool very quickly and is less likely to rise to the ceiling. Consider
additional units at lower mounting heights to help compensate for
this situation.
DS240/DS241 Installation Instructions
Figure 5 - Removing the Backplate
• Bring wiring from the electrical box through the wire entrance.
NOTE: All wiring should be unpowered.
• Securely mount the backplate to the electrical box.
• Return the circuit carrier plate to the backplate. Secure it in place
with the single mounting screw.
• Repeat this mounting procedure for the transmitter.
© 2004 Bosch
P/N: 22066P
Page 3
• Slide the Remote Indicator Connector over the pins just to the
right of the receiver’s terminal strip.
Only apply power after all connections have been made
and inspected.
• Wire the transmitter and receiver terminals as follows (see
Figure 6).
NOTE: Do not install on verified fire circuits.
DS240/DS241 Receiver
Fire Trouble 10 to 32
Alarm Alarm VDC
4 5 6 7 8 9
Alarm Loop
Fire Alarm
Control Panel
End of Line
Remote Indicator
Plate Connector
Fire Alarm
Control Panel
Alarm Loop
Power Loop –
Power Loop +
Power Loop –
Power Loop +
Figure 6 - Wiring a Single Unit
NOTE: Do not coil excess wiring inside the units.
Voltage Monitor
Ground (–)
• Transmitter Terminals 1 & 2:
Input power terminals. See Section 2.0 Specifications on page 1
for the operating voltages of the DS240 and DS241.
• Receiver Terminals 1, 2 & 3:
Form "C" Auxiliary relay contacts. Terminals 1 & 2 will open on fire
alarm; Terminals 2 & 3 will close (short) on fire alarm.
• Receiver Terminals 4 & 5:
Normally Open Fire alarm contacts will close (short) on fire
• Receiver Terminals 8 & 9:
Input power terminals. See Section 2.0 Specifications on page 1
for the operating voltages of the DS240 and DS241.
Before starting this section, confirm that all connections have been
made and are secure, then apply power to both units.
• Press the Aim Mode button (directly above the green LED) on the
transmitter (see Figure 8). This allows the transmitter to power
up while its cover is off.
Remote Indicator Plate
The DIS2000 Remote Indicator Plate is shipped with the DS240/
DS241 as a standard accessory. Although the Remote Indicator Plate
is not required, the manufacturer recommends its installation to
provide a means of checking the condition of the detector from ground
NOTE: The DIS240 remote indicator should be located no further
than 100 ft (31 m) from the receiver and wired with 18 AWG
(1.2 mm) or larger wire. The DIS2000 may be wired up to
500 ft (152 m) from the receiver.
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P/N: 22066P
NOTE: If connecting a DIS240 Remote Test/Indicator Plate,
consult the DIS240 Installation Instructions (P/N: 24171).
NOTE: Resetting from a fire alarm requires power to the receiver to
be interrupted for at least one second. If not provided by the
fire panel, it can be accomplished by installing a switch in
series with Terminal 9.
If a DIS2000 or DIS240 Remote Indicator Plate will be used, install
the Remote Indicator Connector to the receiver now (see Figure 7).
Green LED
Figure 7 - Connecting the DIS2000 Remote Indicator Plate
• Receiver Terminals 6 & 7:
Normally Closed Trouble contacts will open for trouble alarm.
Yellow LED
Figure 8 - Cutout View of Transmitter Circuit Board Showing
Aim Mode Button Location
- Check the transmitter’s green LED. It should be flashing on
and off.
© 2004 Bosch
DS240/DS241 Installation Instructions
- If the LED is off, check for the presence of power and proper
polarity on Terminals 1 (–) & 2 (+).
- A steady green LED indicates a faulty transmitter, and the unit
should be returned to the factory.
• Check the three receiver LEDs (see Figure 9).
• Replace and secure the transmitter's cover when this alignment
procedure is complete.
• Check the transmitter's green LED. It should be flashing.
• Replace and secure the transmitter's access door.
• Align the receiver to the image of the transmitter using the above
preliminary alignment procedure.
Figure 9 - Receiver's LEDs
- It is normal for all of them to be on at this time, with the green
indicator either flashing or constantly on.
• Check the receiver's green LED. It should be flashing. This
indicates that the preliminary alignment is complete.
- If the receiver’s green LED is not flashing, repeat the preliminary alignment procedure for the receiver.
- If all are off, check for the presence of power and proper
polarity on Terminals 8 (–) & 9 (+).
7.2 Sensitivity Adjustment
• Mount an AL240 strobe aiming light or equivalent (such as a
Faraday 5508) as close to the receiver as possible (preferably on
top of the receiver).
Use the chart below (Figure 12) to aid in the sensitivity adjustment.
Recommended Settings
- Point it at the transmitter as your guide for aiming (an aiming
light may not be necessary for short distance separations).
Sw itch
R esp o n se
Beam Length
7.1 Preliminary Alignment
5 se c
30-100 ft (9-31 m)
Each optical module is equipped with two alignment mirrors (one on
each side) for initial alignment (see Figure 10).
5 se c
100-350 ft. 31-107 m)
3 0 se c
30-50 ft (9 -15 m)
3 0 se c
45-75 ft. 14-23 m)
3 0 se c
70-100 ft (21-31 m)
3 0 se c
90-140 ft. 27-43 m)
3 0 se c
120-180 ft (37-55 m)
3 0 se c
160-350 ft (49-107 m)
Figure 10 - The Optical Module
To initially align an optical module, look into either mirror from a side
angle at least 2 ft (61 cm) from the module. The optical module is
pointed at objects seen in the mirror when the orange colored front
bore sight is in the center of the rear bore sights (see Figure 11).
Front Bore Sight
Rear Bore Sights
Figure 12 - Recommended Settings Chart
NOTE: Positions 8 and 9 are not valid positions. They are not to be
• Select the appropriate sensitivity setting from the above chart
based on the distance between the transmitter and receiver.
• Set the receiver’s Sensitivity switch at this setting.
Figure 11 - View of the Alignment Mirror
• The Sensitivity switch is located just to the right of the optical
module on the receiver. The indicator or pointer marking runs
along the side of the switches' shaft (see Figure 13).
with Bore Sights Aligned Properly.
HINT: Use alignment sights like aiming a gun.
• Rotate the transmitter's optical module left or right until the
image of the aiming light (or receiver image, if aiming light is not
used) can be seen in the mirror.
- If initially aimed too high or low, adjust the Vertical Fine Tuning
adjustment allen screw (with supplied allen wrench) slightly
up or down until the image is found.
• Use the Vertical Fine Tuning adjustment screw and the
Horizontal Fine Tuning adjustment screw to fine tune the image
to the center of the mirror (in-line with the front and rear bore
DS240/DS241 Installation Instructions
Figure 13 - Sensitivity Switch
• The recommended settings chart lists distances with some
settings that overlap. For more sensitive detection, select the
lower number setting. For better immunity to false alarms, select
the higher number setting.
© 2004 Bosch
P/N: 22066P
Page 5
7.3 Fine Tune Alignment
• Connect the supplied TC2000 Test Cable to Pins 1, 2 and 3 of
P6, the group of pins located just to the right of the receiver’s
terminal strip (see Figure 14).
• An alarm test may be performed here if desired by connecting
the white and black wires of the TC2000. To reset the unit,
temporarily remove power.
• Press the receiver’s Set-up button located just below the P6/test
cable connection (see Figure 15). Press only if the covers are
on both transmitter and receiver.
- This starts a one to two minute automatic internal setup
process that results in a reference voltage for measuring
beam blockages.
Figure 14 - TC2000 Connection
- Temporarily disconnect the Remote Indicator Plate connector, if
- The red and yellow LEDs should turn off, and the green LED
will turn on steady. After some voltage fluctuations, the meter
should settle at 5.0 VDC.
• Connect a 20,000 Ohm/volt (or greater) DC VOM to the black
(–) and red (+) leads of the TC2000.
- Set meter scale so that readings of 0.0 to 5.0 VDC can be
NOTE: Be careful not to block the beam or move the units during
this time.
• Check the three LEDs on the receiver.
- If the beam is being received by the receiver, the green LED
should be flashing, and the red and yellow LEDs should be on
- If the green LED is on steady, the beam is not reaching the
receiver. If this is the case, the preliminary alignment procedure should be attempted again.
• Observe the meter readings and adjust the receiver’s optical
module using the Horizontal and Vertical Fine Tuning adjustment
screws for a maximum reading on the meter. This is the most
critical process of alignment. For the most effective operation
of this system, the peak voltage during fine tune alignment
must be obtained.
NOTE: When performing fine tune alignment, keep arms and hands
away from the front of the receiver and out of the beam path.
• The maximum voltage peaked reading will vary depending on the
distance between the transmitter and receiver. The acceptable
peaked voltage range is 0.50 to 5.00 V. The voltage at the
receiver is greater at shorter distances. It is very important to
peak the voltage to insure a stable trouble free detector.
Make a note of the alignment voltage. It may be helpful if
future troubleshooting is necessary.
• After completing the fine tune alignment, remove the test cable,
then replace and secure the receiver's cover.
• Check the status of the receiver’s green LED. It should still be
• With the meter still connected to the test cable, re-install the test
cable to P6 through the opening in the cover (red lead towards
center of unit).
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P/N: 22066P
Figure 15 - The Receiver's Set-up Button
- At the end of the setup period, the receiver’s green LED will
flash, and the voltage will drop to between 3.8 and 4.2 VDC.
This is a reference voltage that later readings can be compared to when determining the need for cleaning.
• If the voltage is not between 3.8 VDC and 4.2 VDC, push the Setup button again.
• After set-up is complete, remove the test cable (and reconnect
the Remote Indicator Plate connector if used).
• Replace and secure the access door.
Other Information
8.1 Fire Alarm Reset
To reset the receiver after a fire alarm has occurred, remove power
from the receiver for at least one second, then re-apply (see also,
Section 8.4 Power Outage on page 7).
8.2 Cleaning
At least once a year, the outside of the covers should be cleaned with
a common window cleaner and a soft, clean cloth. Under normal
conditions, this should not result in a trouble alarm as long as the
beam is not continuously blocked for more than 18 sec. After cleaning,
recheck the reference voltage. If the voltage is less than 3.8 VDC, or
greater than 4.2 VDC, calibrate the units (see Section 8.3 Reference
Voltage Calibration).
8.3 Reference Voltage Calibration
The reference voltage of the detectors should be checked at least
once a year (or more often if required by local regulations or authorities
having jurisdiction). Clean covers are necessary for proper
reference voltage readings.
© 2004 Bosch
DS240/DS241 Installation Instructions
To check the reference voltage, remove the receiver's access door
and measure the reference voltage, using the supplied test cable, or
measure the voltage at the DIS240 Remote Indicator Plate (if used).
If the voltage is less than 3.8 VDC, remove the cover and perform a
fine tune alignment including use of the Set-up switch. If above 4.2
VDC, press the Set-up button. Calibration is not necessary if the
voltage is between 3.8 VDC and 4.2 VDC.
8.4 Power Outage
When power is removed, then reapplied to the receiver (such as in a
power outage or alarm reset), the original reference voltage
information is lost.
If the cover is on at the time of power-up, the receiver will automatically
restart the internal set-up process (to get a new reference voltage)
when power is applied. If the cover is off, the Set-up button will have to
be pressed after the cover is reattached.
30% 40%
UL Maximum Sensitivity
UL Minimum Sensitivity
30 (9m)
80 (24m)
130 (40m)
230 (70m)
180 (56m)
280 (85m)
330 (100m)
Distance Between Transmitter and Receiver
8.5 Remote Indicator Plate Connector
Momentarily connecting the orange and black leads of the connector
(see Figure 16) will produce a test alarm. For a remote test, install a
momentary switch between the orange and black wires.
Figure 17 - Smoke Density/Obscuration Chart
The next chart (Figure 18) shows the Sensitivity Pot Setting (total
obscuration) that is needed for alarm.
ORANGE - Remote Alarm Test
BLUE - Analog ref. voltage out
BLACK - Common (-)
RED - Red LED indicator
YELLOW - Yellow LED indicator
GREEN - Green LED indicator
P ot
at Alarm
0 or 3
1 or 6
Figure 16 - Remote Indicator Plate Connector
The black and blue wires may be connected to an analog meter for
reference voltage measurements. The red, yellow, and green wires
may be connected to remote LEDs.
Figure 18 - Sensitivity Pot/Obscuration Chart
Each wire is current limited to a maximum of 10.0 mA DC.
8.6 Smoke Density/Obscuration Information
8.7 Field Sensitivity Measurements
The total obscuration of the infrared beam is dependent upon the
density and width of the smoke cloud along the beam path. As the
width of the smoke cloud increases along the beam path, less dense
smoke will be needed for an equal obscuration of the beam path. In
practice, the smoke cloud is assumed to be the entire distance of the
beam path; therefore, the total obscuration required for alarm should
be selected by setting the Sensitivity Pot Setting as recommended in
Section 7.2 Sensitivity Adjustment on page 5.
The detectors automatically compensate for the effects of dust or dirt
accumulation on the covers and for component aging. The NFPA
requires that the detector's sensitivity be measured in the field, and
requires that these measurements be made within one year after
initial installation and every alternate year thereafter (reference NFPA
72). A TK240 Test Kit should be ordered to test the unit’s sensitivity in
the field. The chart (Figure 19) below represents alarm information
for the filters in the TK240 as well as the Sensitivity Test Kit provided
with the units.
Since the total obscuration of the beam by smoke increases with
distance between the units (because more smoke will be within the
beam path), the detector can be made less sensitive as the distance
increases. Additionally, the sensitivity of the detector should be made
less at greater distances because obscuration by other contaminants
such as dust increases. The sensitivity should be set to respond to
the proper smoke obscuration and also to reduce the chance of a
false activation.
As shown in Figure 17, if the expected smoke density is 0.5 percent
per ft (per 30 cm), the obscuration at 50 ft (15 m) is 20 percent and at
250 ft (95 m) it is 73 percent.
DS240/DS241 Installation Instructions
© 2004 Bosch
Must NOT
0 or 3
1 or 6
0% (no filter)
0% (no filter)
20% filter
20% filter
40% filter
40% filter
40% filter
60% filter
60% filter
80% filter
80% filter
80% filter
Figure 19 - Sensitivity/Response Chart
P/N: 22066P
Page 7
The Sensitivity Test Kit (supplied) may be used to check the sensitivity
of the detectors during installation only. For field testing, the TK240
must be used. Each filter decreases the detector’s signal by a defined
amount. When each filter is placed in front of the receiver’s optical
module for at least 30 sec (5 sec for position 0 or 1), the approximate
sensitivity setting of the installed detector can be determined by the
detector's response as shown in Figure 19 on page 7.
NOTE: Testing these detectors will activate a fire alarm. Be sure to
inform all concerned personnel before performing and testing.
8.8 FCC Compliance Notice
This equipment has been tested and found to comply with the limits
for a class B digital device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment
generates, uses, and can radiate radio frequency energy and, if not
installed and used in strict accordance with the manufacturer's
instructions and recommendations, may cause harmful interference
to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment
does cause harmful interference to radio or television reception, which
can be determined by turning the equipment on and off, the user is
encouraged to try to correct the interference by one or more of the
following measures:
• Re-orient or relocate the receiving antenna.
• Increase the separation between the equipment and the receiver.
• Connect the equipment into an outlet on a circuit different from
the receiver.
• Consult the installing company or an experienced radio/TV
technician for help.
The booklet, "How to Identify and Resolve Radio-TV Interference
Problems,” prepared by the Federal Communications Commission
(FCC) may prove helpful. This booklet is available from the U. S.
Government Printing Office, Washington, DC 20402. Please specify
Stock No.004-000-00345-4.
Page 8
P/N: 22066P
© 2004 Bosch
DS240/DS241 Installation Instructions
DS240/DS241 Installation Instructions
© 2004 Bosch
P/N: 22066P
Page 9
10.0 Installing Multiple Units
Page 10
P/N: 22066P
© 2004 Bosch
DS240/DS241 Installation Instructions
11.0 Quick Start Installation Flow Chart
DS240/DS241 Installation Instructions
© 2004 Bosch
P/N: 22066P
Page 11
© 2004 Bosch
130 Perinton Parkway, Fairport, NY 14450-9199 USA
Customer Service: (800) 289-0096; Technical Support (888) 886-6189
Installation Instructions
DS240/DS241 Long Range Beam Smoke Detectors
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