IFD-E Flame Detector User Manual
IFD-E Flame Detector
User Manual
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Hochiki Europe (UK) Ltd
General
Description
The flame detector is designed for use where open flaming fires may be expected. It responds to the light
emitted from flames during combustion. The detector discriminates between flames and other light
sources by responding only to particular optical wavelengths and flame flicker frequencies. This enables
the detector to avoided false alarms due to such factors as flicking sunlight.
Electrical Considerations
The flame detector can be connected in many different electrical configurations depending on the
application. The detector requires a 24Vdc (14Vmin. to 30Vmax.) supply to operate. The detector can be
connected as a two-wire loop powered device increasing its supply current to signal that a flame has
been detected. See Fig 8. The supply connections to the detector are polarity sensitive.
Also available are volt free contacts from two internal relays RL1 (Fire) and RL2 (Fault or pre-alarm).
Using the relay contacts connected in a four-wire configuration the detector status can be signalled back
to control equipment. See Fig 9.
Removing the detector front cover provides accesses the detector terminals and configuration DIL switch.
See Fig.4.
Alarm Response Modes
The detector is normally configured to latch into an alarm state when a flame is detected. The supply to
the detector has to be broken in order to reset the detector.
The configuration DIL switch within the detector can be set to place the detector into a non-latching mode.
The detector can then also produce proportional analogue current alarm signals, in other words, 8-28mA
or 4-20mA. In non-latching mode the detector only produces an alarm signal when a flame is in view
resetting itself to normal when the flame has gone.
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Application for Flame Detectors
Flame detectors are used when detection is required to be:
Unaffected by convection currents, draughts or wind
Tolerant of fumes, vapours, dust and mist
Responsive to a flame more than 25m away
Fast reacting
The detector is capable of detecting the optical radiation emitted by burning material even noncarbonaceous materials. e.g. Hydrogen
Numerous other potential fire sources can be detected such as:
Liquids
Solids
Gases
● Aviation Fuels (kerosene)
● Coal
● Butane
● Ethanol
● Cotton
● Fluorine
● Methylated Spirits
● Grain & Feeds
● Hydrogen
● n-Heptane
● Paper
● Natural Gas
● Paraffin
● Refuse
● Off Gas
● Petrol (gasoline)
● Wood
● Propane
Typical applications examples are:
● Agriculture
● Coal handling plant
● Pharmaceutical
● Aircraft hangars
● Engine rooms
● Power plants
● Atria
● Generator rooms
● Textiles
● Automotive industry
● Metal fabrication
● Transformer stations
- spray booths
● Paper manufacture
● Waste handling
- parts manufacture
● Petrochemical
● Woodworking
Applications and Locations to Avoid:
● ambient temperatures above 55°C
● large IR sources – heaters, burners, flares
● close proximity to RF sources
● obstructions to field of view
● exposure to severe rain and ice
● sunlight falling directly on the detector optics
● large amounts of flickering reflections
● spot lighting directly on the detector optics
Quantities Required and Positioning of Detectors
The number of detectors required and their position depends on:
the anticipated size of the flame
the distance of the flame from the detector
the angle of view of the flame detector
The flame detector is designed to have a class 1 performance as defined in BS EN54-10:2002 on the
high sensitivity setting. That is the ability to detect an n-heptane (yellow) fire of 0.1m² or methylated spirit
(clear) fire of 0.25m² at a distance of up to 25m within 30 seconds.
The detector can be set to have to a lower sensitivity setting equivalent to class 3 performance. Class 3
performance is defined as detecting the same size fires as for class 1 but at a distance of only 12m.
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In fact, the flame detector will detect fires at distances of up to 40 metres, but the flame size at such
distances needs to be proportionally greater in order to be sure of reliable detection. Thus the yellow
flickering flame that can be detected at 25m, provided that its size is not less than 0.1m², will have to be
0.4m² in order to be detected at 40metres.
In a rectangular room the distance from the flame detector to the fire is calculated by the formula:
In the example shown in Fig 1 the room in which the flame detector is to be installed measures 20m x
10m x 5m; the maximum distance from the detector to the flame will therefore be:
Fig 1 Calculation of distance from detector to flame
Field of View
The flame detector has a field of view of
approximately 90°, as shown in the diagram
below.
Fig 2 Conical field of view of the flame detector
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Fig 3 Detector Field of View Plot
The flame detector should be positioned at the perimeter of the room, pointing directly at the anticipated
flame or at the centre of the area to be protected. If the detector cannot ‘see’ the whole of the area to be
protected, one or more additional detectors may be required.
The flame detector is not affected by normal light sources but should be positioned so that sunlight does
not fall directly onto the viewing window.
Detector Window Contamination
It is important to keep the detector window clean and checks should be carried out at regular intervals –
determine locally according to the type and degree of contamination encountered – to ensure optimal
performance of the flame detector. Although the IR detectors can detect flames when the window is
contaminated, there may be a reduction of sensitivity as shown in Table 1.
Contamination
Typical percentage of normal response
Water spray
75%
Steam
75%
Smoke
75%
Oil film
86%
Salt water film
86%
Dry salt deposits
86%
Table 1 IR Detector window contamination
UV/IR detectors are more susceptible to window contamination and must be kept clean
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Detector Interior
IR Optics (IR optical flame sensors and filters)
Supply ON (Green) (steady if detector
functioning correctly)
Fire (Red) (indicates a FIRE detected)
Test (Yellow) (indicates detector in test mode)
UV Optics (Option) (UV optical flame sensor if
fitted)
DIL Switch (select detector functions)
Connection Terminals
Fig 4 Detector with Front Cover removed
Electrical Connections
The flame detector has eight connection terminals as show in Fig 5a and 5b. Removing the front cover of
the flame detector accesses the connections. The cable is passed through the gland holes in the base of
the detector. Note – When the IFD-E is used on a Conventional system a Fire Resistor will be required
across the FLAME relay, the value of this resistor will be dependent on Control Panel, check with
manufacturer.
Fig 5a Electrical Connection Terminals (for Conventional system)
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Fig 5b Electrical Connection Terminals (for Analogue system)
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Fig 5c Electrical Connection Terminals
(for Analogue system incorporating CHQ-POM Powered Output Module)
NOTE: The CHQ-POM has a variable output, note this should be set at 30mA.
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Connection Terminal Descriptions
Terminal No.
Mnemonic
Function
1
+IN
Power Supply +V. +IN is the power supply input to the flame detector
and is normally 24Vdc with respect to terminal 2. The current
consumption of detector can be monitored to determine the detector
status (Fault, Normal, Pre-alarm, Fire). If the detector is in latching
mode then this supply line must be broken in order to reset the
detector. A thermal fuse within the detector will blow and break the +IN
connection if the detector operating temperature is exceeded.
2
-IN
Power Supply 0V. –IN is the return path for the detector supply current.
-IN is also internally connected to terminal 4.
3
+R
Remote Detector Test Input +V. No connection to +R is necessary if
the detector optical and circuit test feature is not required. If 24Vdc is
applied to terminals 3 and 4 the detector internal optical test sources
will activate to simulate a flame. The detector yellow test LED will
flicker to indicate an optical test is progress. The detector will then
alarm indicating that the test was successful.
4
-R
Remote Detector Test Input 0V. No connection to -R is necessary if the
detector optical and circuit test feature is not required.
-R is internally connected to terminal 2.
RL1
Flame Relay RL1. This volt free contact is normally open (N/O) and
only closes when a flame has been detected. If the detector is in
latching mode (see DIL switch settings) the contact will remain closed
once a flame has been detected. Only when the detector supply +IN is
broken will the detector reset and the contact open once again. The
contact can be changed to a normally closed (N/C) state by moving the
link on JP1 in the rear of the detector.
Maximum relay contact ratings: Power=3W, Current=0.25Amp,
Voltage=30Vdc. Resistive loads only.
RL2
Fault or Pre-alarm Relay RL2. This volt free contact is normally closed
(N/C) if the detector has no faults and the supply voltage between
terminals +IN and –IN is the correct value. If the detector mode is
changed (see DIL switch settings) this relay can be de-energised to
reduce the detector current consumption. Alternatively RL2 can be set
to provide a pre-alarm fire signal. The normal contact state can be
changed state by moving the link on JP2 in the rear of the detector.
Maximum relay contact ratings: Power=3W, Current=0.25Amp,
Voltage=30Vdc. Resistive loads only.
5
6
7
8
Table 2 Connection Terminal Descriptions
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Selectable Detector Functions
(DIL Switch Settings)
Fig 6 DIL Switch with Detector Front Cover Removed (Normal factory settings shown)
Selectable Functions
DIL Switch Settings
Relay RL2 Function:
1
2
RL2 off (No fault relay) – For lowest detector current consumption.
0
0
RL2 off, or UV pre-alarm, flame or electrical sparks detected.
1
0
RL2 energised on IR pre-alarm
0
1
RL2 detector fault relay (Energised if detector powered and no faults)
1
1
Detector Supply Current (Detector Status): [-/ = see Output Mode below]
3
4
Low current mode, 3mA / 9mA (RL1 Only), 8mA / 14mA (RL1 & RL2)
0
0
Two-wire current signalling only. No relays operating. 4-20mA, 4/20mA
1
0
Two-wire current signalling 8-20mA, 8/20mA and both relays operating.
0
1
Two-wire current signalling 8/28mA and both relays operating.
1
1
Output Mode:
(-) Proportional analogue supply current.
(/) Step change, supply current.
5
Non-latching fire alarm signalling. (-)
0
Latching fire alarm signalling. (/)
1
Response Time:
Faster response times reduce the optical interference immunity.
6
7
Slowest ≈ 8s
0
0
Medium ≈ 4s
1
0
Fast ≈ 2s
0
1
Very Fast ≈ 1s
1
1
Sensitivity: See EN 54-10
denotes Factory settings
Table 3 DIL Switch Settings
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Low Class 3
0
High Class 1
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Theory of Operation
The detector responds to low-frequency (1 to 15 Hz.) flickering IR radiation emitted from flames during
combustion.
IR flame flicker techniques enable the sensor to operate through a layer of oil, dust, water vapour, or ice.
Most IR flame sensors respond to 4.3µm light emitted by hydrocarbon flames. By responding to 1.0 to
2.7µm light emitted by every fire all flickering flames can be detected. Gas fires not visible to the naked
eye e.g. hydrogen may also be detected.
The dual (IR²) and triple (IR³) IR photoelectric detectors, responding to neighbouring IR wavelengths,
enable it to discriminate between flames and spurious sources of IR radiation.
The combination of filters and signal processing allows the sensor to be used with little risk of false
alarms in difficult situations characterised by factors such as flickering sunlight.
Signal Processing
The detector views the flame at particular optical wavelengths. The more differing optical wavelength
signals available the better the detector is at discriminating between flames and false optical sources.
So although IR², IR³ and UV/IR² detectors can detect similar sized flames at the same distances, the
UV/IR² detector will give the greatest optical false signal immunity as it has the most diverse selection of
optical wavelengths.
The detector processes the optical signal information to determine if a flame is in view. This is achieved
by comparing the signals with known flame characteristics stored within the detector.
Fig 7 Block Diagram of the Detector Signal Processing
If the detector has interpreted the optical signals as a fire then it produces the required output responses.
This will be in the form of supply current changes and the illumination of the red fire LED. The fire relay
will also change state if required.
The detector is constantly checking itself to ensure it is performing correctly. If a fault occurs the detector
supply current will reduce, the fault relay will de-energise and the green supply LED will no longer
illuminate constantly.
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Connection Information
NOTE 1
Screened cable should be used with one end of the screen connected to earth. Also care should be
taken not to run the detector cable next to power cables.
Fig 8 Basic 2 Wire Connection Diagram
The simplest method of connecting the flame detector is in a 2-wire configuration as shown above. With
a 24Vdc supply the current (i) drawn by a detector/detectors can be monitored to determine the detector
status. The DIL switches within the detector can be set to produce different current values (i) to suit
control systems.
Detector Supply Current
i @ 24Vdc
DIL Switch
Setting
Comment
Normal
Quiescent
Current
Alarm
(Fire) Current
3mA
9mA
0
0
0
0
4mA
20mA
0
0
1
0 For 4-20mA systems, no relays
8mA
14mA
1
1
0
0
8mA
20mA
1
1
0
1 For 4-20mA systems & relays
8mA
28mA
1
1
1
1 Fire control panels
1
2
3
4
Lowest power configuration,
RL1 only
Lowest power configuration &
relays
Table 4 Detector Supply & Alarm Currents
If the detector supply current falls below the normal quiescent current consumption then a fault is present.
This could be simply an open circuit cable fault or a fault within the detector possibly due to the detector
being taken over its rated temperature.
Detectors can be connected in parallel increasing the overall quiescent current required. The alarm
current signal will remain the same with the additional quiescent current drawn from other detectors.
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Fig 9
4 Wire Connection Diagram
NOTE 2
NOTE 3
R = To indicate fire to control unit or interface.
For example, 470R
EOL = End of line device required by some
control units. This is required to monitor the
cable to the detectors and prevent fault
indications on the control unit.
The circuit shown above enables the flame detectors to interface with most type of fire alarm control
systems. The fire relay RL1 is used to switch the required alarm load ‘R’ to generate a fire alarm signal.
An end of line device ‘EOL’ mounted in the last detector provides the system with the ability to monitor the
detector fault relay RL2 and the integrity of the interconnecting cables.
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Installation
It is important that the detectors are installed in such a way that all terminals and connections are
protected to at least IP20 with the detector coverR fitted. The earth bonding terminals are provided for
convenience where continuity of a cable sheath or similar if required.
Adjustable mounting brackets and weather shields are available as shown below.
Fig 10 Stainless Steel Adjustable Mount
Fig 11 Stainless Steel Weather Shield
Functional Testing
When 24Vdc power is applied to the detector the green
supply on indicator LED will illuminate. The fault relay
RL2, if selected with the DIL switch, will energise and
the contact between terminals 7 and 8 will close.
If 24Vdc is applied to terminals 3 and 4 or terminal 3 is
linked to terminal 1 the detector will perform a self-test.
It does this by causing internal optical test sources to
simulate the behaviour of flames and the detector will
alarm.
Alternatively a portable flame sensor test
unit is available to generate simulated
flame behaviour and test the detector a
few metres in front of the detector. See
Fig 12.
Finally, provided it is safe to do so, carry
out a flame test using a flickering flame
source, such as a portable Bunsen
burner. See Fig 13.
A still non-flickering flame will not
produce a response from the detector
Fig 12 Portable Flame Detector Test Unit
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Fig 13 Portable Bunsen Burner
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Service & Repairs
Servicing of the fire protection system should be carried out by competent persons familiar with this type
of system, or as recommended by the local regulations in force.
Only the manufacturer or equivalent authorised body may carry out repairs to the flame detectors. In
practical terms this means that flame detector may be repaired only at the manufacturer’s factory.
Hochiki Europe (UK) Ltd
Grosvenor Road, Gillingham Business Park,
Gillingham, Kent, ME8 0SA, England
Telephone: +44(0)1634 260133 Facsimile: +44(0)1634 260132
Email: [email protected]
Web: www.hochikieurope.com
Hochiki Europe (UK) Ltd. reserves the right to alter the specification of its products from time to time without notice. Although every effort has been made to
ensure the accuracy of the information contained within this document it is not warranted or represented by Hochiki Europe (UK) Ltd. to be a complete and upto-date description. Please check our web site for the latest version of this document.
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