Fire Fighting Enterprises FIRERAY 2000 EExd User Manual
FIRERAY 2000 EExd
Hazardous Area Smoke Detector
Installation Guide
KEY FEATURES
Flameproof Receiver and Transmitter
Standard Fireray Controller Unit
High Coverage - up to 15002m per system
Low Cost
Beam Range 10 metres to 100 metres
12 Volts dc to 24 Volts dc operation
Selectable Alarm Thresholds
Low Current Consumption
Manual or Automatic Fire Alarm Reset
Automatic Fault Alarm Reset
Ground Level Electronics
Extremely Rugged
Easy installation
Low maintenance
DESCRIPTION
The FIRERAY 2000 EExd SMOKE DETECTOR SYSTEM is designed primarily to protect EExd, IIB
hazardous areas.
It consists of a standard Fireray 2000 Controller/Analyser, combined with highly rugged flameproof
Transmitter and Receiver heads.
The Transmitter and Receiver Heads are designed to be mounted within the protected hazardous area,
whilst the Analyser is housed outside it. Using the Standard Analyser unit in this way allows a
significant cost reduction when compared to a system utilising flameproof enclosures for all component
parts. The maximum lateral beam coverage is 15m per Fireray System installed.
Once installed, the Transmitter Head projects a modulated Infra-Red Beam across the protected area, to
the Receiver head mounted opposite. The received signal strength is monitored and analysed in the
Ground Level Controller. Should the beam strength fall below the preset threshold for more than 8 -10
seconds, a Fire Alarm is signalled to the Control Equipment. The analyser also incorporates monitoring
for cable breaks or loss of function at the Transmitter or Receiver. If the signal strength is reduced
suddenly (<5 seconds) by greater than 93% a Fault Alarm is indicated to the Control equipment. The
Fire and Fault Alarm outputs are provided via two sets of Voltage-Free change-over relay contacts.
The Fire Alarm Relay may be set for latched or auto-reset operation as desired. The Fault Alarm is
designed to auto-reset once the signal is returned to serviceable limits.
The system may be used with ‘intelligent’ or ‘non-intelligent’ systems. Due to the very low current
consumption, back-up battery life is extended and the system may be powered from alarm loop supplies
in most cases.
PARTS LIST
1 x Transmitter Head (With Clear Lens)
1 x Receiver Head (With Dark Lens)
1 x Controller/Analyser Unit
1 x Adjustable Head Mounting Bracket
1 x Bag of Bracket Fixings
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APPLICATIONS
Ex II 2 G Environments
Refineries
Mills
Munitions Factories
Munitions Stores
Flammable Liquid Stores
Flammable Gas Stores
Flammable Powder Stores
Industrial Plants
Power Stations
Warehouses
Applications requiring highly rugged
detector heads
1 x Test Filter
1 x Installation Guide (This document)
2 x Allen keys (5mm & 10mm)
STATEMENT OF INTENDED USE
This system is intended for use as a Smoke Detector only, in EExd IIB, or lower grade areas. It must
not be used in areas with a greater hazard rating. It must be installed and tested by approved, competent
personnel, in accordance with all regulatory and local codes of practise. No liability shall be accepted
for installations not conforming to this requirement.
The equipment is covered by certificate number Sira03ATEX1504, and the following instructions
apply.
1. The equipment may be used with flammable gases and vapours with apparatus group II and with
temperature class T6. in the ambient temperature range -20°C to +55°C.
2. The equipment is only certified for use in ambient temperatures in the range -20°C to +55°C and
should not be used outside this range.
3. Installation should be carried out by suitably trained personnel in accordance with the applicable
code of practice e.g. EN 60079-14:1997.
4. Inspection of this equipment shall be carried out by suitably trained personnel in accordance with
the applicable code of practice e.g. EN 60079-17.
5. The equipment does not have any user-serviceable parts and must be returned to the manufacturer
for servicing or repair.
6. This Installation Guide contains the system Principle of Operation; system Specification;
Installation Precautions; Installation Setting Up and Testing; Installation diagrams.
7. On the Transmitter and Receiver, the allowable gap is 0.2mm maximum between the Housing and
the Cover,
8. The certification of this equipment relies upon SM87 Enclosure Component (typically Aluminium
Alloy or Stainless Steel) Certificate No. Baseefa03ATEX0345U/1 from MEDC Ltd.
9. If the equipment is likely to come into contact with aggressive substances, then it is the
responsibility of the user to take suitable precautions that prevent it from being adversely affected,
thus ensuring that the type of protection provided by the equipment is not compromised.
Aggressive substances : e.g. acidic liquids or gases that may attack metals, or
solvents that may affect polymeric materials.
Suitable precautions : e.g. regular checks as part of routine inspections, or
establishing from the material’s data sheets that it is
resistant to specific chemicals.
NOTE : If in doubt, contact the supplier.
10. Label details :
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WARNING
The area into which the Fireray parts are to be fitted must be made safe before attempting any work
on the system. It must also be checked thoroughly prior/during/after commissioning, to ensure it
cannot compromise the safety of the area in which it is fitted. Note that only the Transmitter and
Receiver parts may be installed in the hazardous area, NOT the Controller Unit.
If the flamepath of the enclosure is damaged in any way, the unit must be returned to the
manufacturer and a new unit purchased.
PRINCIPLE OF OPERATION
General
The Fireray system operates by passing an infra-red beam between a Transmitter and Receiver, through
the protected area. The received signal strength will be attenuated if smoke is present in the beam. The
beam strength is measured continuously and, should any attenuation be present which exceeds presets
thresholds, fire or fault alarms are generated as appropriate. Each installed Fireray can cover an area 7.5
metres either side of the beam, giving a maximum coverage of up to 15002m with a 100m beam path
length.
Transmitter and Receiver Units
A modulated Infra-Red light beam is projected from the Tx (Transmitter ) via it’s optical system. The
projected beam has a circular footprint, with a useable spread of approx 3m @ 100m range. The Rx
(Receiver) has a corresponding filtered optical system which collects and focuses the beam onto a
photo-detector. During installation, the Rx has a maximum beam acceptance angle of up to 5
(dependant on gain and threshold settings). The wide Tx beam, in conjunction with the large Rx
acceptance angle simplifies alignment and gives good tolerance to beam mis-alignments after
installation.
Controller Unit And Alarm Thresholds
The signal received at the Rx is amplified and filtered to reject sunlight and other unwanted optical
noise such as may be caused by ambient lighting,. The signal is then passed to the Controller Unit,
where it undergoes further filtering and validity checking, before finally being analysed for signal
strength. The signal is then compared to a reference level (determined by the user’s threshold setting),
and should the signal be reduced below the set threshold, the FIRE ALARM relay will be activated
within approx 12 seconds. Three user selectable threshold setting are available **. Note that only one
threshold switch must be closed to select the required threshold. A red lamp on the Controller Unit
front panel also indicates a FIRE ALARM condition.
Controller Unit -Fault Thresholds
If the signal is reduced suddenly by more than 93% in 8 to 10 seconds, perhaps due to total beam
blockage, a cable break, or the Tx or Rx becoming unserviceable, the controller interprets this as a fault
situation. Loss of power to any of the system parts will also cause a fault signal to be generated. In any
of these events, the controller will activate the FAULT ALARM relay continuously. The system will
return to normal operation immediately, once the correct signals are restored, except in the event of a
power loss to the controller, in which case normal operation is resumed after 50 seconds from
restoration of power. A yellow lamp (LED4) in the Controller Unit also indicates when the system is in
a FAULT or RESET condition.
Controller Unit - Compensation (AGC) Operation And Action At Compensation Limit
The Controller Unit also incorporates an AGC (Automatic Gain Control) system , which monitors very
slow changes in the received signal due to contamination of the optical system (EG: build up of dust on
the lenses) and any changes due to system ageing. If the signal is reduced by more than approx 11%, the
AGC system is activated. Then if the signal is still low after 1.5 hours, a 7% increase is made to the
system gain, to bring the signal strength back into the nominal range. Additionally, should the signal
strength increase, perhaps due to improved alignment following building movement, the system can
reduce its gain in 7% steps. From an initial nominal setting, up to 11 increasing and 3 decreasing
correction steps are possible.
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Two possible actions are selectable, once the system has exhausted all compensation steps, as follows:-
Leave the COMP switch in the Controller unit OPEN for BS5839 installations (UK). This
setting allows generation of a FIRE ALARM after reaching the compensation limit, even
though a FAULT ALARM will be active. This is the only time Fire and Fault indications can
occur together.
Close the COMP switch if it is required that FIRE ALARM generation is inhibited once a
FAULT ALARM has occurred, due to reaching compensation limit.
Controller Unit - Relay Outputs
The Controller Unit has two sets of outputs for Fire and Fault indication, in the form of voltage free
single pole changeover relay contacts. The FIRE relay may be set to give either latching or non-latching
operation, determined by a switch (ALARM LATCH) on the Controller pcb. With the switch closed,
latching operation is selected.
Controller Unit - Signal Strength Metering
A ‘Metering ‘ output is also provided, to assist with installation. This gives a dc voltage which is
proportional to the received signal strength and can be monitored using a voltmeter.
Controller Unit - System Resetting
The system can be reset in any of three ways, as follows :-
Using the RESET switch in the Controller Unit (Normally only used during installation).
By taking the External Reset input low (to system 0V) for at least 5mS.
By de-powering the system for 1 second, then re-powering.
Following a reset the system takes 50 seconds to self-calibrate. During this time the Fireray adjusts it’s
100% signal reference level and so must have a clear unobstructed beam. No tests should be carried out
until this initialisation period has elapsed.
Notes On Resetting Using The Internal RESET Switch
Note that for correct operation, the internal RESET switch must not be set to OFF whilst either of
the HIGH or LOW signal lamps in the Controller Unit are illuminated. The gain must be set
correctly to extinguish both lamps first. If this is not done the system AGC is locked and will not
operate. (This does not apply to the other two reset methods).
SUMMARY OF SYSTEM CONDITIONS :-
Possible Causes of FAULT Alarms
Controller Unit RESET switch in ON position.
Controller Unit EXTERNAL RESET input active ( at 0V)
No power to Controller unit
No Power to Tx unit
Beam obscuration >93% for >5 seconds (for whatever reason)
Tx or Controller power cable break.
Receiver Signal cable break.
AGC at limit of compensation.
Rx/Tx Mis-alignment causing low signal strength
System unable to initialise following reset, due to inability to calibrate correctly (perhaps caused by
interference or testing of the beam before expiry of the 50 second calibration period.
High or Low signal when Controller Unit’s RESET switch set to OFF (AGC locked out).
Possible Causes Of FIRE Alarms
In normal use, beam strength reduced by more than the set threshold (Smoke in beam).
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