Hochiki America Corporation SPC-24 Operating and maintenance manual

Issued January, 2007
INSTALLATION PROCEDURE
FOR SPC-24
PHOTOELECTRIC
BEAM DETECTOR

2
Contents
Contents ....................................................................................................................2
1. General Description..............................................................................................4
1.1. Detection principle........................................................................................................................ 4
2. Installing the detector...........................................................................................5
2.1. Siting.............................................................................................................................................. 5
2.2. Mounting and removing the detector.......................................................................................... 6
2.3. Opening the detector cover........................................................................................................... 7
2.4. Installation.................................................................................................................................... 7
2.4.1. Installation option ................................................................................................................. 7
2.4.2. Installation procedure ........................................................................................................... 8
2.5. Closing the detector cover.......................................................................................................... 11
2.6. Adjustment procedure ................................................................................................................ 11
2.6.1. Alignment adjustment......................................................................................................... 11
2.6.2 Setting the Sensitivity & Switches for Operation .............................................................. 12
2.6.3. Signal strength adjustment ................................................................................................ 13
2.7. Sensitivity check procedure ....................................................................................................... 14
3. Maintenance........................................................................................................15
3.1. General ........................................................................................................................................ 15
3.2. Visual check ................................................................................................................................ 15
3.3. Operation checks......................................................................................................................... 15
3.4. Precautions for insulation resistance checking ........................................................................15
3.5. Re-initialisation after cleaning or re-adjustment..................................................................... 15
4. Terminal layout and part designation ...............................................................16
4.1. Emitter ........................................................................................................................................ 16
4.2. Receiver ....................................................................................................................................... 16
5. Summary of the SPC-24's functions...................................................................17
5.1. Alarm signal output and indicator lamp...................................................................................17
5.2. Fault signal output and indicator lamp ....................................................................................17
5.2.1. General................................................................................................................................. 17
5.2.2. After adjustment/re-initialisation.......................................................................................17
5.2.3. During normal operation..................................................................................................... 17
5.3. Indication of normal operation................................................................................................... 18

3
5.4. Sensitivity and operation setting............................................................................................... 18
5.5. Total obscuration of the beam.................................................................................................... 18
5.6. Automatic compensation for change of receiver's signal strength ..........................................18
6. Specification........................................................................................................19
7. Sensitivity selection............................................................................................20
8. Troubleshooting...................................................................................................21
8.1. Operating indicator LED fails to flash...................................................................................... 21
8.1.1. Receiver ................................................................................................................................ 21
8.1.2. Emitter ................................................................................................................................. 21
8.2. Fire signal continues after reset................................................................................................ 21
8.3. Fault signal cannot be reset....................................................................................................... 21
8.3.1. Fire also occurs..................................................................................................................... 21
8.3.2. Fault only ............................................................................................................................. 21
8.4. Detector generates fire - panel does not register condition.....................................................22
8.5. Detector generates a fault - panel does not register condition................................................22
9. Installation guide lines.......................................................................................23
9.1. General installation conditions.................................................................................................. 23
9.2. Installation in Saw-tooth type ceilings...................................................................................... 24
9.3. Installation in circular type ceilings.......................................................................................... 24
9.4. Installation in sloped ceilings.................................................................................................... 24
9.5. Installation in a monitor roof..................................................................................................... 25
9.6. Installation in corridors or aisles............................................................................................... 25
9.6.1. Closed corridor..................................................................................................................... 25
9.6.2. Corridor with open adjoining aisle ..................................................................................... 26
9.6.3. Corridor with corners .......................................................................................................... 26
9.7. Installation precautions ............................................................................................................. 27
9.8. Smoke Patterns........................................................................................................................... 28

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1. General Description
The photo-electric beam detector consists of an emitter and a receiver which face each
other at a distance of between 5 and 100 meters.
In the event of fire the smoke generated will decrease the amount of near infra-red light
incident on the receiver. This decrease is electronically interpreted to identify the
occurrence of fire. An important feature of the detector is that it monitors the protected
space linearly. This enables the detector to identify a fire before it spreads, even when the
smoke is scattered over a large area.
The fire detection sensitivity is switch selectable in 3 settings of 25%, 50% and 70%
beam obscuration.
1.1. Detection principle
A near infra-red pulsed beam generated by the emitter is sensed by the photo-diode of
the receiver, where it is converted into an electrical signal. This signal is then amplified
and applied via an A/D converter to a micro-processor. The normal state signal (the initial
beam data) once stored in the micro-processor is used as a reference for comparison with
subsequent beam signals.
When there is sufficient difference between actual beam strength and stored reference
data to indicate the occurrence of a fire, then a fire signal is produced. If an obstacle
blocks the beam, thus abruptly reducing the received beam level, a fault signal is emitted.
(The detector can be set to emit a fire signal after emitting a fault signal.) The same error
signal is emitted when reception signals increase abruptly.
The micro-processor also provides compensation for a change in received signal value
with time, caused by contamination of the optics or slight alignment changes. The
processed signal is adjusted at a rate of ±1% towards the reference data every 20
minutes. When the limit of compensation is reached the micro-processor will automatically
produce a fault signal.
In order to improve the performance of the detector and to enhance the rejection of noise
the emitter and receiver are synchronised together ．The emitter and receiver are
automatically synchronized by using near-infrared beams produced by the emitter. The
emitter and receiver therefore do not need to be interconnected.
（Wireless）

5
2. Installing the detector
2.1. Siting
Select a suitable position for the installation of both emitter and receiver, such that there
are no visible obstructions between them. Remember that the beam detector works on
the principle of reduction of light between the receiver and emitter. If there is any
possibility of an object remaining within the beam for a few seconds then the siting of the
detector is unsuitable.
For mounting either the emitter or receiver it is important to establish that the
mounting place such as the wall is solid and that the beam detector alignment
will be rigid. The wall may appear to be solid, but may be subject to twisting or
other changes when the temperature outside the building varies greatly during
one day, for instance on cold, frosty days. The installer must ensure that the
beam will not be subject to misalignment due to changes in the building itself.
The spacing and siting in specific types of locations is covered in section 9.
The beam detector must not be installed in the following locations :-
Where the ceiling height is greater than 40m
A roof top or place where open air circulates
Where the distance between top and bottom of the space is less than 0.5m
In locations where a large amount of dust, fine powder or water vapour is
present
In locations such as kitchens where smoke occurs normally
In locations which are exposed to extremely high temperatures
Where access to the detector is impossible for maintenance purposes
In locations which may be exposed to sunlight exceeding 5000 lux. It is
recommended that in locations where the beam detector may be surrounded
by glass, then the receiver should where possible be fitted so that it faces a
northerly direction (only relevant to countries in the northern hemisphere)
Where the rigid fixing of either the emitter or receiver is impossible
Where access to the beam detector to align and set is impossible

6
2.2. Mounting and removing the detector
The detector can be fixed to the metal bracket by hooking the detector body to the four
prongs of the mounting plate and then by sliding down firmly until the detector is locked
into place and then locking using the locking screw. (see Figure 1).
Removal of the detector can be achieved by slackening the locking screw and pressing the
locking mechanism located on the bottom left hand side of the detector housing. Whilst
pushing the locking mechanism with either a narrow rod or screw driver the detector is
lifted upwards until it disengages from the mounting plate.
Mounting Plate
Expanded View
Detector Housing
Expanded View
Slide Down Locked
Locking Screw Location Locking Screw Location
(side view)
Front Cover Hinge Mounting Plate
A
B
A: After mounting the detector to the mounting plate, install the rocking screw.
B: Prevents removal of the detector from the mounting plate.
Figure 1 Locking mechanism

7
2.3. Opening the detector cover
Hold the detector cover between the thumb and fingers near the top of the cover and
squeeze the cover firmly so that the top of the cover expands slightly. The cover can then
be pulled away from the detector housing. This should be done by pulling the cover at an
angle of 45°upwards and away from the detector.
Next hold the detector cover firmly at the bottom and pull away from the detector housing
until a click is heard. The cover should now be able to drop down and rest on the cover
retaining clips, thus allowing access inside the detector housing. Refer to Figure 2 for
more details.
Detector Housing
Expanded View
Press Here
Detector Cover
Expanded View
ab
②
①
③
④
Figure 2 Opening the detector housing
2.4. Installation
Refer to section 2.4.1 for installation details:
1 Emitter
1 Receiver
2 Metal mounting brackets
1 Installation manual
4 Fixing screws
2.4.1. Installation option
Before installation of the beam detector it will be necessary to determine which type of
wiring method will be used for connection between the beam detector and the control
panel. It is possible to connect the beam detector as either a 4-wire or 3-wire system,
depending on the type of control panel used. The 3-wire system can use less cable cores
and therefore a cheaper cable, however it may not be possible to install the detector in
this way. If in doubt refer to the control panel manufacturer to decide which type of wiring
method to use.
The receiver alone emits signals when there is a fire. The emitter can therefore be
equipped with a local power supply.
Note: Do not touch the black window of cover
for dew condensation prevention.

8
2.4.2. Installation procedure
Screw the detector mounting plate firmly to the wall or other suitable mounting point. Pull
the cable out about 6 inches from the wall and strip 5 inches of the outer insulation jacket.
Push cable wires through the hole in the back side of the SPC-24. The SPC-24 will accept
wire sizes ranging from 14 to 20 AWG.
Switch box
Hooking plate
Wall
6”
Figure 3 Wiring method (1)
Open the detector cover as described in section 2.3 and then take the wires into the back
of the detector through the hole so that they come out below the terminal connector. The
wires can be installed either behind the detector or from below the detector, depending on
the suitability of the installation. If the wires are to come in from below then it will be
necessary to break the knock-out slot from the bottom of the detector body (located near
to the retaining clip).
Figure 4 Wiring method (2)
After wiring, pull the cable tight to take up the slack. Push any excess wire lengths toward
the back of the detector. Be careful not to catch the wires on the detector cover.
Finally, push any excess wire lengths into the electrical box and mount the detector onto
the mounting plates.

9
Figure 4 Wiring method (3)
Hook the back of the detector body to the 4 prongs of the mounting plate and slide down
firmly, ensuring that the cables are not trapped or damaged by the detector. The detector
body should lock into place by the locking mechanism which is located on the bottom right
hand corner of the detector and then secured using the locking screw. Refer to the
mechanical drawing Figure 1.
Connect the wires which run from the receiver to the emitter according to the choice of
system either 3-wire or 4-wire. The wiring for both methods are shown in the wiring
diagrams Figure 6 and Figure 7. The receiver alone emits signals when there is a fire. The
emitter can therefore be equipped with a local power supply.
The wires should be pushed into the holes of the connector whilst the white push key is
pressed with a small screwdriver. This will enable the wire to push completely home. Pull
the wire to make sure that it is firmly held by the connector.
E1 E1E1E1
E2E2E2E2
24V
24V+
24V24V24V
0V0V0V0V
24V-
zone+
zone-
F1F1F1F1
F2F2F2F2
T1T1 T2 T2
FromControlPanel
EmitterEmitter
Receiver Receiver
EndofLineRelay
EndofLineResistor
ValuedependantonControlPanel.
Checkwithmanufacturer.
Figure 6 Wiring diagram for 4-wire connection

10
ValuedependantonControlPanel.
Checkwithmanufacturer.
E1 E1E1E1
E2E2E2E2
24V
24V+
24V24V24V
0V
0V
0V
0V
24V-
zone+
F1F1F1F1
F2F2F2F2
T1T1 T2 T2
FromControlPanel
EmitterEmitter
Receiver Receiver
EndofLineRelay
EndofLineResistor
Figure 7 Wiring diagram for 3-wire connection
In order to comply with regulations for device and wiring supervision it may be necessary
to use an end of line relay and end of line resistor. Also the contact across the detection
zone for fire is a relay contact and it will generally be necessary to include a resistor or
other current limiting element in series with the relay contact.
Because the beam detector is powered by a separate line from the control panel it will be
necessary to reset this power line to remove a fire condition from the beam detector.
The connections for the emitter and receiver are detailed below. The terminal names are
marked above the terminals on the beam detector. Refer to section 4 for a drawing of the
terminal positions.
Emitter:
E1, E2 Zone or Power (in/out) (Non Polarized)
Receiver:
F1, F2 - Fire alarm output contacts. Normally open
T1, T2 - Fault output contacts. Normally closed
24V, 0V - Beam detector power supply
Now set up the beam as described in sections 2.6 and 2.6.2.

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2.5. Closing the detector cover
Move the cover upwards so that the cover engages with the top of the detector housing.
Then hook the top of the cover over the metal hook protruding outward from the top of
the detector housing. Pull down the top of the cover ensuring that it is flush with the
detector housing top. Now push the cover at the bottom firmly towards the detector
housing until it locks back into place. Refer to Figure 8 for more details.
Detector Housing
Detector Cover
①
②
Figure 8 Closing the detector cover
2.6. Adjustment procedure
Adjust the detector as follows:
a. Use the sight hole and optical axis control to adjust the optical axis of the emitter.
b. Set the distance switch on the emitter according to the monitoring distance and close
the cover of the emitter.
c. Use the sight hole and optical axis control to adjust the optical axis on the receiver.
d. Set the sensitivity of the receiver and close the cover.
Closing the cover on the receiver will automatically synchronize the receiver with the
emitter. The level of the reception signal is automatically adjusted to initiate fire
monitoring. It takes about two minutes for fire monitoring to begin after the receiver
cover is closed. In the meantime, take care not to block the beam. Refer to section 4 for
details of the position of the relevant parts on the detector when making the following
adjustments.
2.6.1. Alignment adjustment
Open the covers of the emitter and receiver as described previously. At the receiver
confirm that both sensitivity setting switches SW1 and SW2 are set to OFF (sensitivity off),
refer to Figure 10. Power up the receiver and emitter and then wait two minutes for the
beam detector to stabilise. At this time the green operating LED will flash in
synchronisation with the green alignment setting LED once every 3 second.
Move to the emitter and look through the alignment sight hole. Turn either the horizontal
or vertical alignment screws until the receiver can be seen in the centre of the sight hole.
Note: Do not touch the black window of cover
for dew condensation prevention.

12
When installing the units in a dimly lit area, it may be difficult to see the receiver and
emitter. In this case alignment can be made by turning the alignment adjustment wheels
until the alignment setting LED can be seen in the centre of the sight hole.
Set the distance switch on the emitter according to the monitoring distance, then close
the cover on the emitter. Then adjust the optical axis on the receiver similarly. (refer to
figure 12).
Sight Hole
Other Detector
Figure 9 Detector alignment
When necessary, the optical axis can be fine-tuned as follows:
With the emitter cover open, hold down the push switch (see Chapter 4) for about five
seconds, then release it. Then the monitor lamp (green) and fault lamp (yellow) on the
receiver will start blinking at intervals of three seconds. (During that time,
synchronization is being established with the emitter.) After that, in addition to the
monitor lamp (green) and the fault lamp (yellow), either of the monitor LEDs* (yellow,
green, and red) will start to blink. (During that time, the reception level is automatically
adjusted.) When the automatic adjustment of the reception level is successfully
terminated, the fault lamp (yellow) will go out and then the monitor lamp (green) and the
green monitor LED will start to blink. When that happens, the monitor LED can be used
as a level meter for reception signals. Turn the optical axis control to maximize the
reception signal. When synchronization is established with the emitter, every push of the
push switch for about five seconds will adjust the reception level automatically.
*These LED’s are small square LED’s located in the main PCB and are located below the
main alignment and status LED’s (refer to section 2.5). If the signal stays always in the
yellow LED region then the signal strength is too weak. If the signal stays always in the
red LED region then the signal strength is too high. Twice flashing is stronger than once
flashing. If the cover will be closed(push switch will keep being pushed) then signal
strength will be adjusted automatically, and signal will stay always in the green LED
region.
2.6.2 Setting the Sensitivity & Switches for Operation
Set the distance range using switches of the emitter SW1 and SW2 according to the
distance of emitter to receiver. The range for the positions of SW1 and SW2 are shown in
Figure 10 together with a front view of the on and off positions as viewed with the
detector in its normal installation orientation.
Figure 10 Distance range setting
Set the sensitivity to the required value using switches of the receiver SW1 and SW2
according to the distance and ceiling height. SW4 is switch for operation. The sensitivity
for the positions of SW1 and SW2, operational mode for the position of SW4 are shown in
Figure 11.
ON
１
２
Ｒange SW1 SW2
5m〜35m ＯＮ ＯＦＦ
20m〜100m ＯＦＦ ＯＦＦ

13
Figure 11 Sensitivity and operation setting
2.6.3. Signal strength adjustment
The reception signal level can automatically be initiated by closing the cover on the
receiver. Before closing the cover on the receiver, check if the sensitivity and functional
switches and the distance switch on the emitter (see Chapter 2.6.2) are appropriately set. 
Closing the cover on the receiver synchronizes the receiver with the emitter, then
automatically adjusts the amplification factor of the reception circuit, then initiates fire
monitoring. While synchronization is being established with the emitter and while the
reception signal level is automatically adjusted, the monitor lamp (green) and fault lamp
(yellow) on the receiver blink at intervals of three seconds. If the system shifts
successfully to the monitoring state, the monitor lamp (green) alone will blink.
If synchronization is not established with the emitter, or if the reception signal level is not
successfully adjusted, the fault lamp (yellow) alone will blink, emitting a fault signal.
The status (normal monitoring, fault, fire, or other) of the detector can be checked by the
lamps on the receiver. The lamps on the emitter do not change their condition with the
status of the detector. The status of the detector corresponds to the displays as indicated
in Table 1. Receiver Emitter
Monitorlamp/fire
lamp(green/red) Opticalaxis lamp(green) Faultlamp (yellow)
MonitorLED
(yellow/
green/red)
Monitor
lamp(green) Opticalaxis lamp(green)
Opticalaxisadjustmentin
progress(whenthepower
isturnedon) ○(green) ○*1  ○○
*1
Synchronizationin
progress ○(green)  ○  ○ ○*1
Automaticadjustmentin
progress ○(green)  ○ ○*1○○
*1
Monitoringinprogress ○(green)    ○ ○*1
Fire ●(red)    ○ ○*1
Fault ○(green)*2 ○  ○○
*1
○Blinking (at intervals of three seconds) ●Lit
*1: Closing the cover hides the lamp. *2: The lamp may not blink in the case of some faults.
Table 1 Status display of the detector
ON
１
２
３
４
Ｓensitivity SW1 SW2
Ａdjusutment ＯＦＦ ＯＦＦ
25% ＯＮ ＯＦＦ
50% ＯＦＦ ＯＮ
70% ＯＮ ＯＮ
SW3 SW4
Faultsignalreset
ＯＦＦ auto
ＯＮ manual
Notuse

14
If the detector goes into fault after initialisation the following conditions may have
occurred :-
The cover of the receiver was closed, but the sensitivity was left OFF
The sensitivity has been set but the cover of the receiver was not closed
The light level is too low or too high reaching the beam
The distance setting switch of the emitter has not been set correctly
Run through the alignment and signal strength procedure again until the beam detector
will initialise correctly.
2.7. Sensitivity check procedure
After installing the detector or during periodic maintenance it is important to ascertain
that the detector has the correct fire sensitivity. This can be achieved by the use of filters.
Hochiki produce two types of filters for this purpose, the first being the TSK-B100, the
second being the SPB-24N.
TSK-B100 filters have been designed as rugged long lasting test filters for testing all
models of Hochiki beam detector and have been manufactured from wire mesh. They also
come with an attachment so that they can be mounted to the Hochiki detector removal
pole, thus enabling testing of the filter from ground level. SPB-24N filters have been
designed as disposable test filters for testing the Hochiki SPB-24N or SPC-24 beam
detector and have been manufactured from plastic.
First determine the sensitivity that the beam detector should be set to and then select the
correct filter values from Table2. Using the lowest filter value prove that the detector is
not too sensitive by placing the filter between the emitter and receiver for at least 30
seconds. It is not set to the correct sensitivity if the detector goes into fire alarm (or fault)
during this process.
Next place the higher value filter between the emitter and receiver for at least 30 seconds.
During this period a fire alarm should occur. If no alarm occurs or a fault occurs then the
detector is not operating as expected.
Table 2 Test filter values
TSK-B100 SPB-24N
25% Operation 36% No.3.5
Non-operation 19% No.2.5
50% Operation 65% No.5
Non-operation 36% No.3.5
70% Operation 85% No.6
Non-operation 50% No.4.5
25%
setting
50%
setting
70%
setting
Sensitivity
setting (%) Type of test Filter Value Filter Number

15
3. Maintenance
3.1. General
The detector contains an automatic compensation function, which allows the detector to
operate correctly even when the amount of signal reaching the receiver has changed (the
compensation rate is ±1%/20 minutes). This means that minor changes due to
contamination and beam alignment will not affect the sensitivity of the detector. There is
of course a limit that the detector can compensate for and this is -50% and +50% of the
initial setting. In order to maintain proper performance the detector should be checked
every six months.
3.2. Visual check
Check the condition of both the emitter and receiver for physical damage or any other
condition that might impair proper operation. Ensure that both the receiver and emitter
are still firmly secured to the wall or other fixing point.
If necessary clean the lens cover with a damp soft cloth. Washing liquid or detergent must
not be used.
3.3. Operation checks
Perform the sensitivity check function as defined in section 2.7.
3.4. Precautions for insulation resistance checking
If the wiring to a beam detector is to be tested for insulation resistance using a high
voltage tester such as a Megger, the wiring to the beam detector must be disconnected
from the detector otherwise permanent damage of the detector may result.
3.5. Re-initialisation after cleaning or re-adjustment
The detector incorporates non-volatile memory, where backup copies of the initial settings
and dirt progress are periodically made. This memory is retained even after the power is
turned off. Turning the power off and back on will cause the detector to reload the
settings which were in the memory before the power was turned off, then to shift to the
monitoring state.
To clean the cover, readjust the optical axis, or do something similar during maintenance
work, the memory must be cleared. The memory can be cleared in either of the following
two ways:
- Open the cover on the receiver while in a normal monitoring state.
- Turn on the power with the receiver cover open.

16
4. Terminal layout and part designation
4.1. Emitter
Figure 12 Emitter Construction
4.2. Receiver
Figure 13 Receiver Construction
Light Beam Adjustment
Screw (Horizontal) Light Beam Adjustment
Screw (Vertical)
Operating Indicator
LED (Green)
Alignment Setting LED
(Green)
Emitter Wiring Terminals
Distance Setting Switches
SW1, SW2
E2 E2 E1 E1
Signal Strength LED (Red)
Light Beam Adjustment
Screw (Horizontal)
Light Beam Adjustment
Screw (Vertical)
Operating Indicator LED
(Green) and Fire Indicator
LED (Red)
Alignment Setting LED
(Green)
Receiver Wiring Terminals
Fault LED (Yellow)
Sensitivity Switches
SW1, SW2
Operation Setting Switches
SW3, SW4
Signal Strength LED (Yellow)
Push Switch
NC NC T2 T1 F2 F2 F1 F1 0V 0V 24V 24V
Signal Strength LED (Green)

17
5. Summary of the SPC-24's functions
5.1. Alarm signal output and indicator lamp
When the beam is obscured by an amount that exceeds the sensitivity setting of the
detector then a fire signal is produced and lighting the fire LED on the receiver.
It should be noted that the SPC-24 has a sophisticated processing and analysing circuit
and therefore a fire will not occur immediately the obscuration exceeds the sensitivity
value, but will take typically 10 to 15 seconds to produce the fire signal. The fire decision
is based on an averaging technique and therefore the time to fire alarm will vary
depending on the level of obscuration and the sensitivity setting.
5.2. Fault signal output and indicator lamp
5.2.1. General
The beam detector may produce a fault condition for one of many different reasons, which
will depend on whether the detector has just been set up or is in normal operation. The
fault signal will be produced and flashing the yellow fault LED on the receiver.
5.2.2. After adjustment/re-initialisation
The beam detector will produce a fault after or during adjustment for one of the following
reasons :-
The receiver cover has been left open for three hours
The cover of the receiver was closed, but the sensitivity was left OFF
The light level is too low reaching the beam
The light level is too high reaching the beam
The sensitivity has been set but the cover of the receiver was not closed within
5 minutes
Synchronization with the emitter is not successful
5.2.3. During normal operation
The beam detector will produce a fault during normal operation for one of the following
reasons :-
The limit of contamination has been reached. The detector is only able to
compensate for contamination or alignment change up to a certain point
The obscuration is greater than 90% (a fire alarm signal will also be
produced(This can be changed by configuration. See Chapter 2.6.2.))
The receiver has come out of synchronization with the emitter.
(Synchronization with the emitter is compensated for at intervals of five
minutes or so. If the emitter alone is turned off and back on, or if the beam is
blocked for more than 30 minutes, compensation will lag behind, resulting in a
fault.)

18
5.3. Indication of normal operation
When the covers of the receiver or emitter are closed then the green LED visible through
the outside of the case will flash every 3 seconds to indicate that the detector is operating
correctly.
If the cover of the receiver is open then both green LED's (the centre alignment LED is not
visible unless the cover is open) on the receiver will flash every 3 seconds. If the cover of
the emitter is open then both green LED's (the centre alignment LED is not visible unless
the cover is open) on the emitter will flash every 3 seconds. The rate of flash will not be
affected by opening the cover of the detector.
5.4. Sensitivity and operation setting
The receiver is provided with a DIP switch with 4 bits available for setting the sensitivity
and operation of the beam detector.Bits 1 and 2 are allocated to sensitivity setting, while
bits 3 and 4 are allocated to settings by operation type. The sensitivity settings can be
25%; 50%; 70% or no operation. For operation types, bit 3 can be set to switch the
signals to be emitted when the beam is blocked to fault and fire, or to fault alone. Bit 4
can be set to switch between the automatic or manual recovery from the fault status. For
details, see Chapter 2.6.2.
The sensitivity setting only affects the determination of the fire signal. Basically the higher
the percentage setting, the less sensitive the beam detector will be since the production of
a fire signal requires that the signal seen by the receiver should be reduced by more than
the amount of the sensitivity setting. For example a sensitivity of 25% requires a
reduction of the signal by 1/4 of its initial value to produce a fire.
The fault states to be manually recovered from are faults occurring during normal
monitoring (dimmed by more than 90%, compensation limit reached, and out of
synchronization). Similarly to fires, these faults can be recovered from by pressing the
recovery button* on the receiver.
*The conditions for manual recovery are specified in clause 6. If the conditions are unmet,
use manual recovery.
5.5. Total obscuration of the beam
If the beam detector is totally obscured, a fault signal will be produced. The fault condition
will disappear when the total obscuration condition is removed. The operation type can be
set with SW4 (refer to figure 11).
5.6. Automatic compensation for change of receiver's
signal strength
From the time that the beam detector is initialised, the signal at the receiver is checked
every 20 minutes for variation and will be altered by ±1% back towards the original stored
value. The beam detector will store the initialisation value, when either the cover is closed
after the sensitivity has been set (sensitivity not in the no operation position). If the
power is turned off and back on with the receiver cover closed, the compensation
percentage before the power was turned off will be read from the internal memory and
the operation will continue. The compensation percentage can be cleared either by
opening the receiver cover while being energized or by turning the power on with the
receiver cover open.

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6. Specification
InstallationEnvironment Indooruseonly
PrincipleofOperation Lightbeamobscuration(nearinfra-red)
RatedVoltage 24VDC
RatedCurrent 50mA
Emitter  : 15〜41VDC
Operatingvoltagerange Receiver : 15〜33VDC
Peaksurgevoltage 42V
Emitter  : 50μA （at24V,25℃）
Supervisorycurrent(average) Receiver : 200μA （at24V,25℃）
Compensationmethod 1%every20mins.towardsinitialvalue
Compensationlimits +50%to-50%oftheinitialvalue
Firecondition RedfireLEDonreceiverilluminatedandfirerelaycloses
Faultcondition YellowfaultLEDonreceiverflashesandfaultrelayopens
Monitorcondition Set up condition : Both green and yellow LED's flash
Normaloperation:GreenLEDflashes
Monitorconditionflashrepetitiontime 1per3seconds
Minimumtimeneededtoresetfromfire 100msec
Minimumtimeneededtoresetfromfault
(manualresetmode) 100msec(lessthan7Vinzonevoltage)
Minimum time needed before beam can
resetafterfireproduced 3seconds
Installationtemperaturerange 32°Fto100°F(0℃to37.8℃)
Maximumhumidity 95%R.H.non-condensing
Coverage 32.8ʼto328ʼ(10mto100m)
Sensitivity 25%,50%,70%／spanobscuration
AllowableLineResistance 50Ω
Allowablemisalignmentangle（MAX) Emitter：±0.5°
Receiver：±1°
Size(emitterorreceiver) 86mm×100mm
Weight Emitter:450gReceiver:500g
Metalmountingbracket:80g
Color WhiteIvory(Blacklens)
Housingmaterial ACSresin
Mounting Wallmounting
Connectionmethod Pushinterminals
Wiringmethod 3or4wireconfiguration

20
7. Sensitivity selection
If requirements or standards are provided for the sensitivity of the photoelectric beam
detector and a test filter, the selection of sensitivity and its test should be performed in
accordance with them. Otherwise, set the sensitivity select switch so that the sensitivity
falls within the sensitivity setting range recommended by the manufacturer in accordance
with the monitoring distance. See table 3.
SensitivitySettingRecommendedbyHochiki
ShallAlarm
Shallnot
Alarm
S1(25%)
S2(50%)
S3(70%)
0
10
20
30
40
50
60
70
80
90
100
0 102030405060708090100
BeamSpanL[m]
Lightobscuration[%/L]
BeamSpan RecommendedSensitivity
（LightObscurationPercentage)
10〜32.1m S1(25%)
31.8〜67.9m S2(50%)
57.5〜100m S3(70%)
Table 3: Sensitivity setting for Beam span