Hochiki America Corporation SPC-24 Operating and maintenance manual

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

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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

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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）

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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

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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

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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.

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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.

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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

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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.