prEN 54-28

SLOVENSKI STANDARD
01-maj-2011
Sistemi za odkrivanje in javljanje požara ter alarmiranje - 28. del: Linijski toplotni
javljalniki brez ponastavitve
Fire detection and fire alarm system - Part 28: Non-resettable line type heat detectors
Brandmeldeanlagen - Teil 28: Nicht-rücksetzbare linienförmige Wärmemelder
Systèmes de détection et d'alarme incendie - Partie 28: Détecteurs de chaleur en ligne
non-réenclenchables
Ta slovenski standard je istoveten z: prEN 54-28
ICS:
13.220.20 3RåDUQD]DãþLWD Fire protection
13.320 Alarmni in opozorilni sistemi Alarm and warning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2011
ICS 13.220.20
English Version
Fire detection and fire alarm system - Part 28: Non-resettable
line type heat detectors
Systèmes de détection et d'alarme incendie - Partie 28: Brandmeldeanlagen - Teil 28: Nicht-rücksetzbare
Détecteurs de chaleur en ligne non-réenclenchables linienförmige Wärmemelder
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 72.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 54-28:2011: E
worldwide for CEN national Members.

Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Normative references .6
3 Terms, definitions and abbreviations .7
3.1 Terms and definitions .7
4 Requirements .8
4.1 General .8
4.2 Nominal activation conditions/sensitivity .9
4.3 Operational reliability .9
4.4 Tolerance to supply voltage . 11
4.5 Performance parameters under fire condition . 12
4.6 Durability . 13
4.7 Electrical stability . 15
5 Tests and assessments methods . 15
5.1 General . 15
5.2 Operational reliability . 19
5.3 Tolerance to supply parameters . 20
5.4 Performance parameters under fire condition . 21
5.5 Durability . 21
5.6 Humidity resistance . 25
5.7 Shock and vibration resistance . 31
5.8 Corrosion resistance . 38
5.9 Electrical stability . 40
6 Evaluation of conformity . 41
6.1 General . 41
6.2 Initial type testing . 41
6.3 Factory production control . 42
6.4 Procedure for modifications . 46
6.5 One-off products, pre-production products, prototypes and products produced in very
low quantities . 47
Annex A (normative) Mounting of the sensing element of NLTHD in the heat tunnel . 48
A.1 General . 48
A.2 Mounting arrangement of sensing element . 48
Annex B (normative) Heat tunnel for response temperature measurements . 50
B.1 General . 50
B.2 Description of the heat tunnel . 50
Annex C (informative) Construction of the heat tunnel . 51
C.1 General . 51
C.2 Heat tunnel construction . 51
Annex D (normative) Test arrangement for vibration tests for sensing element . 53
D.1 General . 53
D.2 Test setup . 53
Annex E (normative) Test apparatus for impact test on the sensing element . 54
E.1 General . 54
E.2 Test apparatus . 54
E.3 Test setup . 54
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU
Construction Products Directive (89/106/EEC) . 57
ZA.1 Scope and relevant clauses . 57
ZA.2 Procedures for the attestation of conformity of Non-resettable line type heat detectors . 59
ZA.3 CE marking and labelling and accompanying documentation . 61
Bibliography . 65

Foreword
This document (prEN 54-28:2011) has been prepared by Technical Committee CEN/TC 72 “Fire detection
and fire alarm systems”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive, see informative Annex ZA, which is an integral part of this document.
EN 54 "Fire detection and fire alarm systems" consists of the following parts:
Part 1: Introduction
Part 2: Control and indicating equipment
Part 3: Fire alarm devices – Sounders
Part 4: Power supply equipment
Part 5: Heat detectors – Point detectors
Part 7: Smoke detectors – Point detectors using scattered light, transmitted light or ionization
Part 10: Flame detectors – Point detectors
Part 11: Manual call points
Part 12: Smoke detectors – Line detector using an optical light beam
Part 13: Compatibility assessment of system components
Part 14: Guidelines for planning, design, installation, commissioning, use and maintenance
Part 15: Point detectors using a combination of detected phenomena
Part 16: Voice alarm control and indicating equipment
Part 17: Short circuit isolators
Part 18: Input/output devices
Part 20: Aspirating smoke detectors
Part 21: Alarm transmission and fault warning routine equipment
Part 22: Resettable line-type heat detectors
Part 23: Fire alarm devices – Visual alarms
Part 24: Components of voice alarm systems – Loudspeakers
Part 25: Components using radio links and system requirements
Part 26: Carbon monoxide detectors – Point detectors
Part 27: Duct smoke detectors
Part 29: Multi-sensor fire detectors - Point detectors using a combination of smoke and heat sensors
Part 30: Multi-sensor fire detectors - Point detectors using a combination of carbon monoxide and heat
sensors
Part 31: Multi-sensor detector – Point detectors using a combination of smoke, carbon monoxide and
optionally heat sensors
Part 32: Guidelines for the planning, design, installation, commissioning, use and maintenance of voice alarm
systems
NOTE This list includes standards that are in preparation and other standards may be added. For current status of
published standards refer to www.cen.eu.
Introduction
Non-resettable Line Type Heat Detectors (NLTHD) have been used for a considerable number of years and
are incorporated into fire detection systems and in some countries even into fire alarm systems if accepted by
the fire brigade. These detectors are typically used in areas where point type heat detectors are presented
with challenging environmental characteristics and also, where access to the detectors, may significantly
influence the fire alarm system design.
This standard defines the minimum system functionality for NLTHD products.
Due to the various applications for NLTHD, it is necessary to devise separate environmental classification
tests for the sensing element and the sensor control units of these systems. It is not the purpose of this
standard to define applications or how NLTHD should be used in applications.
Generally NLTHD operate on using the same basic principle. However, they can have different performance
with respect to the temperature response. Therefore they have been classified by a type code which reflects
the nominal alarm temperature, the tolerance range and the maximum ambient temperature at which they
could be used.
1 Scope
This European Standard applies to non-resettable (digital) line type heat detectors consisting of a sensing
element using an electrical sensor cable connected to a sensor control unit, either directly or through an
interface module to a control and indicating equipment intended for use in fire detection and fire alarm
systems installed in and around buildings and civil engineering works.
The non-resettable sensing element has a fixed temperature alarm threshold and does not distinguish
between short circuit and alarm condition.
This European Standard also covers non-resettable line type heat detectors intended for use in the local
protection of plant and equipment.
Non-resettable line type heat detectors with special characteristics and developed for specific risks are not
covered by this standard.
This European Standard specifies the requirements and performance criteria, the corresponding test methods
and the evaluation of conformity of the product to the standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 54-1:1996, Fire detection and fire alarm systems — Part 1: Introduction
EN 54-2:1997, Fire detection and fire alarm systems — Part 2: Control and indicating equipment
EN 54-2:1997/A1:2006, Fire detection and fire alarm systems — Part 2: Control and indicating equipment
EN 54-4:1997, Fire detection and fire alarm systems — Part 4: Power supply equipment
EN 54-4:1997/A1:2002, Fire detection and fire alarm systems — Part 4: Power supply equipment
EN 54-4:1997/A2:2006, Fire detection and fire alarm systems — Part 4: Power supply equipment
EN 54-5:2000; Fire detection and fire alarm systems — Part 5: Point-type heat detectors
EN 54-5:2000/A1:2002; Fire detection and fire alarm systems — Part 5: Point-type heat detectors
EN 54-7:2000; Fire detection and fire alarm systems — Part 7: Point-type smoke detectors
EN 54-7:2000/A1:2002; Fire detection and fire alarm systems — Part 7: Point-type smoke detectors
EN 54-7:2000/A2:2006; Fire detection and fire alarm systems — Part 7: Point-type smoke detectors
EN 50130-4:1995, Alarm systems — Part 4: Electromagnetic compatibility — Product family standard:
immunity requirements for components of fire, intruder and social alarm systems
EN 50130-4/A1:1998, Alarm systems — Part 4: Electromagnetic compatibility — Product family standard:
immunity requirements for components of fire, intruder and social alarm systems
EN 50130-4/A2:2003, Alarm systems — Part 4: Electromagnetic compatibility — Product family standard:
immunity requirements for components of fire, intruder and social alarm systems
EN 60068-1:1994, Environmental testing — Part 1: General and guidance
EN 60068-2-1:2007, Environmental testing — Part 2-1: Tests; Tests A: cold
EN 60068-2-2:1993 +A1:1993, Environmental testing — Part 2: Tests; Test B: dry heat
EN 60068-2-27:1993, Environmental testing — Part 2-27: Tests, Test Ea: shock
EN 60068-2-30:2005, Environmental testing — Part 2-30: Variant 1 test cycle and controlled recovery
conditions: Damp heat, cyclic
EN 60068-2-42:2003, Environmental testing — Part 2-42: Tests, Test Kc: Sulphur dioxide, steady state
EN 60068-2-6:1995, Environmental testing — Part 2: Tests - Test Fc: Vibration, sinusoidal
EN 60068-2-75:1997, Environmental testing — Part 2-75: Tests, Test Eh for test Ehb: impact
EN 60068-2-78:2001, Environmental testing — Part 2-78: Tests, Test Cab: Damp heat, steady state
3 Terms, definitions and abbreviations
For the purposes of this document the terms and definitions given in EN 54-1:1996 and the following apply.
3.1 Terms and definitions
3.1.1
digital detector
detectors, the sensing element of which can be either of two states: standby or alarm
NOTE In this type of detector the alarm threshold is inherent to the construction of the sensing element.
3.1.2
functional unit
part of a line type heat detector in addition to the sensor control unit and the sensing element which is
essential for the function of the line type heat detector
EXAMPLE Terminating device, filter, switch.
3.1.3
linear heat detector
detectors which respond to heat applied to any point along the length of the sensing element
3.1.4
line type heat detector
LTHD
detector which responds to heat sensed in the vicinity of a continuous line
NOTE A line type heat detector may consist of a sensor control unit, a sensing element and functional units.
3.1.5
local protection application
application in which the sensing element is installed in relatively close proximity to the potential fire risk
EXAMPLE pipelines, conveyor belts, combustion engines/turbines, rolling stock, transformers, process dryers, cable
trays, escalators, chemical process equipment, electrical equipment cabinets, ventilation systems (dust collector, hood
extractor, etc.), switch gear (e.g. printing press).
3.1.6
non-resettable line type heat detectors
NLTHD
a LTHD which can only respond once
3.1.7
resettable line type heat detectors
RLTHD
a LTHD which is able to return to its quiescent condition after a response
3.1.8
room protection application
application in which the sensing element is installed at a distance from the potential fire hazard close to the
ceiling or roof of the area to be protected
EXAMPLE car parks (open or closed), road/rail/metro tunnels, floor/ceiling voids, elevator shafts, cold stores,
warehouses, heritage buildings, aircrafts hangars, spray shops, chemical storehouses, ammunition depots, refineries,
silos.
3.1.9
sensing element
heat sensing part of the line type heat detector which can be a fibre optic cable, a pneumatic tube or an
electrical cable
NOTE 1 A sensing element may consist of different segments separated e.g. by functional units or splices.
NOTE 2 The sensing element may be connected directly to control and indicating equipment approved to EN 54-2, an
input/output device approved to EN 54-18 or via a dedicated sensor control unit (see 3.1.10).
3.1.10
sensor control unit
unit that supervises the sensing element and communicates to the control and indicating equipment
NOTE The unit can be remote or an integral part of the control and indicating equipment as defined by EN 54-2.
4 Requirements
4.1 General
4.1.1 Compliance
In order to comply with this standard, non-resettable line type heat detectors shall meet the requirements of
Clause 4, which shall be verified by visual inspection or engineering assessment, shall be tested as described
in Clause 5 and shall meet the requirements of the tests.
4.1.2 Performance type declaration
The manufacturer shall declare the performance type of the NLTHD to be tested using the following format:
Txxx-Vyy-Azzz where:
 Txxx equals the nominal alarm temperature in °C which shall be in the range 54°C to 160°C;
 Vyy equals the variance of the nominal alarm temperature in %, which shall only be 05 or 10;
 Azzz equals the maximum ambient temperature in °C, i.e. the maximum environment temperature at
which the sensing element of the NLTHD could be installed and operated without generating an alarm.
EXAMPLE T085-V10-A066 means a non-resettable line type heat detector with a nominal alarm temperature of
85°C having a variance of 10% (i.e. a minimum alarm temperature of 76.5°C and a maximum alarm temperature of
93.5°C) which can be used for an application in which the ambient temperature is no greater than 66°C
The difference between the maximum ambient temperature and the minimum alarm temperature shall be at
least 4°C.
4.1.3 Environmental groups
Different environmental groups are necessary to reflect the different service environment of the components of
a line type heat detector:
The sensing element shall be classified either environmental group II or III.
The sensor control unit and the functional unit shall be classified either environmental group I, II or III.
NOTE Environmental group I covers equipment likely to be installed indoors in commercial/industrial premises but for
which the avoidance of extreme environmental conditions can be taken into account in the selection of the mounting site.
Environmental group II covers equipment likely to be installed indoors in commercial/industrial premises in all general
areas. Environmental group III covers equipment which is intended to be installed out of doors.
4.2 Nominal activation conditions/sensitivity
4.2.1 Individual alarm indication
Each sensor control unit shall be provided with an integral latched red visual indicator, by which the individual
sensor control unit, which released an alarm, can be identified, until the alarm condition is reset. Where other
conditions of the sensor control unit can be visually indicated, they shall be clearly distinguishable from the
alarm indication, except when the sensor control unit is switched into a service mode. The visual indicator
shall be visible from a distance of 6 m in the direct line of sight perpendicular to the surface, in an ambient
light intensity up to 500 lux.
If more than one sensing element is connected to the sensor control unit, there shall be separate alarm
indication for each sensing element.
4.2.2 Signalling
The line type heat detector shall signal the alarm and fault status to the control and indicating equipment.
If more than one sensing element is connected to a sensor control unit, there shall be separate alarm and fault
signals for each sensing element.
4.3 Operational reliability
4.3.1 Maximum ambient temperature test (endurance) for sensing element
The sensing element of the non-resettable line type heat detector shall be capable of withstanding long term
exposure to temperatures as specified in 5.2.1.
4.3.2 Connection of ancillary devices
Where the NLTHD provides for connections to ancillary devices (e.g. remote indicators, RS 485 interface),
open or short-circuit failures of these connections shall not prevent the correct operation of the NLTHD.
4.3.3 Manufacturer's adjustments
It shall not be possible to change the manufacturer's settings except by special means (e.g. the use of a key,
a code or a special tool or by breaking or removing a seal).
4.3.4 Requirements for software controlled detectors
4.3.4.1 General
For NLTHD, which rely on software control in order to fulfil the requirements of this standard, the requirements
of 4.3.4.2, 4.3.4.3 and 4.3.4.4 shall be met.
4.3.4.2 Software documentation
4.3.4.2.1 The manufacturer shall submit documentation, which gives an overview of the software
design. This documentation shall provide sufficient detail for the design to be inspected for
compliance with this standard and shall include the following as a minimum:
a) a functional description of the main program flow (e.g. as a flow diagram or structogram) including;
1) a brief description of the modules and the functions that they perform,
2) the way in which the modules interact,
3) the overall hierarchy of the program,
4) the way in which the software interacts with the hardware,
5) the way in which the modules are called, including any interrupt processing,
b) a description of which areas of memory are used for the various purposes (e.g. the program, site specific
data and running data);
c) a designation, by which the software and its version can be uniquely identified.
4.3.4.2.2 The manufacturer shall have available detailed design documentation, which only needs to
be provided if required by the testing laboratory. It shall comprise at least the following:
a) an overview of the whole system configuration, including all software and hardware components;
b) a description of each module of the program, containing at least:
1) the name of the module,
2) a description of the tasks performed,
3) a description of the interfaces, including the type of data transfer, the valid data range and the
checking for valid data,
c) full source code listings, as hard copy or in machine-readable form (e.g. ASCII-code), including all global
and local variables, constants and labels used, and sufficient comment for the program flow to be
recognized;
d) details of any software tools used in the design and implementation phase (e.g. CASE-tools, compilers).
4.3.4.3 Software design
In order to ensure the reliability of the NLTHD, the following requirements for software design shall apply:
a) the software shall have a modular structure;
b) the design of the interfaces for manually and automatically generated data shall not permit invalid data to
cause error in the program operation;
c) the software shall be designed to avoid the occurrence of deadlock of the program flow.
4.3.4.4 The storage of programs and data
The program necessary to comply with this standard and any preset data, such as manufacturer's settings,
shall be held in non-volatile memory. Writing to areas of memory containing this program and data shall only
be possible by the use of some special tool or code and shall not be possible during normal operation of the
NLTHD.
Site-specific data shall be held in memory which will retain data for at least two weeks without external power
to the detector, unless provision is made for the automatic renewal of such data, following loss of power,
within 1 h of power being restored.
4.3.5 Sensing element fault
The following fault condition test methods apply:
a) Sensing element faults (see 5.2.2);
b) Low voltage (see 5.3.2)
4.3.6 On-site adjustment of behaviour
The effective response behaviour of a NLTHD is dependent upon both the sensitivity settings of the sensor
control unit and the heat sensing element. Some types of NLTHD therefore may have facilities to adjust the
sensitivity of the NLTHD to suit the application.
If there is provision for on-site adjustment of the response behaviour of the detector then:
a) for each setting, at which the manufacturer claims compliance with this standard, the detector shall
comply with the requirements of this standard, and access to the adjustment means shall only be possible
by the use of a code or special tool;
b) any setting(s), at which the manufacturer does not claim compliance with this standard, shall only be
accessible by the use of a code or special tool, and it shall be clearly marked on the detector or in the
associated data, that if these setting(s) are used, the detector does not comply with the standard.
NOTE These adjustments may be carried out at the sensor control unit or at the control and indicating equipment.
4.4 Tolerance to supply voltage
4.4.1 Variation in supply parameters
The NLTHD shall function correctly within the specified range(s) of the supply parameters as specified in 5.3.1
4.4.2 Low voltage fault
The NLTHD shall signal a fault condition when its input power supply falls below the minimum voltage
specified by the manufacturer as specified in 5.3.2
4.5 Performance parameters under fire condition
4.5.1 Performance and reproducibility
The response temperature of the tested NLTHD's shall be within the manufacturer's performance type
declaration as specified in 5.3.3.
4.5.2 Marking
4.5.3 General
Where any marking on the NLTHD uses symbols or abbreviations not in common use then these shall be
explained in the data supplied with the NLTHD.
The marking shall be visible during installation and shall be accessible during maintenance.
The markings shall not be placed on easily removable parts like screws.
NOTE Where Annex ZA.3 requires the CE marking to be accompanied by the same information as required by this
clause, the requirements of this clause are met
4.5.3.1 Marking of sensor control unit
The sensor control unit shall be clearly marked with the following information:
a) the number and date of this standard;(i.e. EN 54-28:2012)
b) environment classification (Group I, II or III);
c) the name or trademark of the manufacturer or supplier;
d) the model designation (type or number);
e) the wiring terminal designations;
f) some mark(s) or code(s) (e.g. serial number or batch code), by which the manufacturer can identify, at
least, the date or batch and place of manufacture, and the version number(s) of any software, contained
within the sensor control unit.
4.5.3.2 Marking of sensing element
Each sensing element shall be marked with the following information:
a) the number and date of this standard;(i.e. EN 54-28:2012)
b) the performance type of the NLTHD (e.g. T085-V10-A066);
c) name or trademark of the manufacturer or supplier;
d) model designation (type or number);
e) environment classification (Group II or III);
f) some mark(s) or code(s) (e.g. serial number or batch code), by which the manufacturer can identify, at
least, the date or batch and place of manufacture, and the version number(s) of any software, contained
within the sensing element, if applicable.
NOTE If it is not possible to mark directly on the sensing element then the use of at least one label securely fixed to
the sensing element is permitted.
4.5.3.3 Marking of functional units
Each functional unit shall be marked with the following information:
a) the number and date of this standard (i.e. EN 54-28:2012);
b) name or trademark of the manufacturer or supplier;
c) model designation (type or number);
d) environment classification (Group I, II or III);
e) the wiring terminal designations;
f) some mark(s) or code(s) (e.g. serial number or batch code), by which the manufacturer can identify, at
least, the date or batch and place of manufacture, and the version number(s) of any software, contained
within the functional unit.
4.5.4 Data
NLTHD shall either be supplied with sufficient technical, installation and maintenance data to enable their
correct installation and operation or, if all of these data are not supplied with each detector, reference to the
appropriate data sheet shall be given with each NLTHD.
To understand correct operation of the detectors, additional data shall be available that describe the
processing of the signals from the detector. This may be in the form of a full technical specification of these
signals, a reference to the appropriate signalling protocol or a reference to suitable types of sensor control unit
and/or control and indicating equipment, etc.
Installation and maintenance data shall include an in situ test method to ensure that detectors operate
correctly when installed.
NOTE Additional information could be required by organisations certifying that detectors produced by a manufacturer
conform to the requirements of this standard.
4.6 Durability
4.6.1 Temperature resistance
4.6.1.1 Dry heat (operational) sensor control unit
The sensor control unit of the NLTHD shall function correctly at high ambient temperatures as specified in
5.5.1.
4.6.1.2 Cold (operational) sensing element
The sensing element of the NLTHD shall function correctly at low ambient temperatures as specified in 5.5.2.
4.6.1.3 Cold (operational) sensor control unit
The sensor control unit of the NLTHD shall function correctly at low ambient temperatures as specified in 5.5.3
4.6.2 Humidity resistance
4.6.2.1 Damp heat, steady state (endurance) for sensor control unit and sensing element
The NLTHD shall be capable of withstanding long term exposure to a high level of continuous humidity as
specified in 5.6.1.
4.6.2.2 Damp heat, cyclic (operational) for sensing element
The sensing element of the NLTHD shall function correctly at low relative humidity as specified in 5.6.2.
4.6.2.3 Damp heat, cyclic (operational) for sensor control unit
The sensor control unit of the NLTHD shall function correctly at low relative humidity as specified in 5.6.3.
4.6.2.4 Damp heat, steady state (operational) for sensor control unit
The sensor control unit of the NLTHD shall function correctly at low relative humidity as specified in 5.6.4.
4.6.2.5 Damp heat, cyclic (endurance) for sensor control unit and sensing element
The NLTHD be capable of withstanding the effect of cyclic humidity levels as specified in 5.6.5.
4.6.3 Shock and vibration resistance
4.6.3.1 Shock (operational) for sensor control unit
The sensor control unit of the NLTHD shall function correctly when submitted to mechanical shocks which are
likely to occur in the service environment as specified in 5.7.1.
4.6.3.2 Impact (operational) for sensor control unit
The sensor control unit of the NLTHD shall operate correctly when submitted to mechanical impacts as
specified in 5.7.2.
4.6.3.3 Impact (operational) for sensing element
The sensing element of the NLTHD shall operate correctly when submitted to mechanical impacts as specified
in 5.7.3.
4.6.3.4 Vibration, sinusoidal (operational) for sensor control unit
The sensor control unit of the NLTHD shall operate correctly when submitted to sinusoidal vibration as
specified in 5.7.4
4.6.3.5 Vibration, sinusoidal (operational) for sensing element
The sensing element of the NLTHD shall operate correctly when submitted to sinusoidal vibration as specified
in 5.7.5
4.6.3.6 Vibration, sinusoidal (endurance) for sensor control unit
The sensor control unit of the NLTHD shall be capable of withstanding the effect of sinusoidal vibration as
specified in 5.7.6
4.6.3.7 Vibration, sinusoidal (endurance) for sensing element
The sensing element of the NLTHD shall be capable of withstanding the effect of sinusoidal vibration as
specified in 5.7.7.
4.6.4 Corrosion resistance
4.6.4.1 Sulphur dioxide (SO ) corrosion (endurance) for sensing element
The sensing element of the NLTHD shall be capable of withstanding exposure to an SO corrosive
atmosphere as specified in 5.8.1.
4.6.4.2 Sulphur dioxide (SO ) corrosion (endurance) for sensor control unit
The sensor control unit of the NLTHD shall be capable of withstanding exposure to an SO corrosive
atmosphere as specified in 5.8.2.
4.7 Electrical stability
4.7.1 Electromagnetic compatibility (EMC), immunity tests (operational)
The NLTHD shall operate correctly when submitted to electromagnetic interference as specified in 5.9.1
5 Tests and assessments methods
5.1 General
5.1.1 Atmospheric conditions for tests
Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been
allowed to stabilize in the standard atmospheric conditions for testing as specified in EN 60068-1:1994 and as
follows:
a) temperature: (15 to 35) °C;
b) relative humidity: (25 to 75) %;
c) air pressure: (86 to 106) kPa.
If variations in these parameters have a significant effect on a measurement, then such variations should be
kept to a minimum during a series of measurements carried out as part of one test on one specimen.
5.1.2 Operating conditions for tests
If a test method requires a specimen to be operational, then the specimen shall be connected to suitable
supply and monitoring equipment, with characteristics as required by the manufacturer's data. Unless
otherwise specified in the test method, the supply parameters applied to the specimen shall be set within the
manufacturer's specified range(s) and shall remain substantially constant throughout the tests. The value
chosen for each parameter shall normally be the nominal value, or the mean of the specified range. If a test
procedure requires a specimen to be monitored to detect any alarm or fault signals, then connections shall be
made to any necessary ancillary devices (e.g. through wiring to an end-of-line device for conventional
detectors to allow a fault signal to be recognized).
The details of the supply and monitoring equipment and the alarm criteria used should be given in the test
report.
5.1.3 Mounting arrangements
Unless otherwise stated, the specimen shall be mounted by its normal means of attachment in accordance
with the manufacturer's instructions. If these instructions describe more than one method of mounting, then
the method considered to be most unfavourable shall be chosen for each test.
5.1.4 Tolerances
Unless otherwise stated, the tolerances for the environmental test parameters shall be as specified in the
basic reference standards for the test (e.g. the relevant part of EN 60068).
If a specific tolerance or deviation limit is not specified in a requirement or test procedure, then a deviation
limit of ± 5 % shall be applied.
5.1.5 Procedure for measurement of response temperature
This procedure is to verify the manufacturer's performance type declaration and to establish any deviation in
system response temperature following the environmental tests.
The NLTHD shall be connected to a suitable supply and monitoring equipment in accordance with 5.1.2
The response temperature of the NLTHD shall be measured using the heat tunnel described in Annex A and
Annex B.
The orientation of the sensing element in the heat tunnel shall be chosen arbitrarily.
Before the measurement, stabilize the temperature of the air stream and the section of sensing element to be
heated to a temperature 25°C below the manufacturer's declared maximum ambient temperature, Azzz or to
25°C, which ever is the higher. The measurement is then made by increasing the air temperature in the tunnel,
linearly with respect to time and at the rate of rise specified in the applicable test procedure, until the supply
and monitoring equipment indicates an alarm or the manufacturer's limits have been exceeded at least by 5 K.
During the measurement, the airflow in the tunnel shall be maintained at a constant mass flow, equivalent to
(0,8 ± 0,1) m/s at 25 °C. The air temperature shall be controlled to within ± 2 K of the nominal temperature
required at any time during the test.
The response temperature T, shall be recorded at the moment an alarm is indicated.
NOTE 1 Care should be taken not to subject detectors to a damaging thermal shock when transferring them to and
from a stabilized or alarm temperature.
The length of sensing element, used, L , shall be 10 m, unless specified otherwise in the appropriate test.
A section of (0,4 ± 0,15) m (L ) of sensing element shall be placed in the centre of the heat tunnel (see
test
Annex A), perpendicular to the air flow.
The remaining section of the sensing element (L – L ) not exposed to the induced test temperature shall
1 test
remain at ambient temperature (23 ± 5) °C during the measurement unless otherwise stated in the individual
tests.
NOTE 2 To facilitate the test procedure, it may be necessary to introduce easily detachable connections between
different sections of the sensing element. The losses introduced by these connections should be taken into account when
determining L .
NOTE 3 The manufacturer may specify a minimum length of sensing element that needs to be connected before
and/or after the section of the sensing element being heated (L ).
test
5.1.6 Provision for tests
Two continuous samples of at least 300 m of sensing element and one continuous sample of sensing element of
the maximum length as defined by the manufacturer (all taken from different production batches numbered from
1 to 3) shall be provided to conduct the tests in 5.1.7. If applicable, at least three specimens of sensor control
unit and/or, at least three specimens of each functional unit shall also be provided. The exact length of sensing
elements and the number of sensor control units and/or functional units shall be agreed between the
manufacturer and the testing laboratory. If more than three sensor control units and/or functional units are
provided then the test schedule (see 5.1.7.) can be modified as appropriate.
NOTE 1 If there are different types of sensor control units, sensing elements and/or functional units (e.g. with different
environment groups), at least three specimens/samples shall be provided for each type
The specimens/batches submitted shall be deemed representative of the manufacturer's normal production with
regard to their construction and calibration.
NOTE 2 The mean response temperature of the three specimens, as found in the reproducibility tests, should
represent the production mean. The limits specified in the reproducibility test should also be applicable to the
manufacturer's production.
5.1.7 Test schedule
The specimens shall be tested according to the following test schedule (see Table 1).
Table 1 —Test schedule
D)
Test Clause Specimen No
Specimen No Specimen Specimen
of sensor No of No of
control unit sensing functional
A)
element unit
B) B)
Maximum ambient temperature test (endurance) for 5.2.1 1 to 3 1 to 3 1 to 3
sensing element
C
Sensing element fault 5.2.2 2 1 2
C
Variation in supply
...