Fire detection and fire alarm system - Part 28: Non-resettable line-type heat detectors

This European Standard applies to non-resettable line-type heat detectors consisting of a sensing element using an electrical sensor cable which can be connected to a sensor control unit or 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 (see EN 54 1:2011).
The non-resettable sensing element has a fixed temperature alarm threshold and does not distinguish between short circuit and alarm condition.
This European Standard specifies the requirements and performance criteria, the corresponding test methods and provides for the Assessment and Verification of Constancy of Performance (AVCP) of non-resettable line-type heat detectors to this European Standard.
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.

Brandmeldeanlagen - Teil 28: Nicht-rücksetzbare linienförmige Wärmemelder

Diese Europäische Norm gilt für nicht-rücksetzbare linienförmige Wärmemelder mit einem Sensorelement, das ein elektrisches Sensorkabel nutzt, welches mit einer Auswerteeinheit oder, entweder direkt oder über ein Interface Modul, mit einer Brandmelderzentrale verbunden sein kann, die zur Verwendung in Brandmeldeanlagen vorgesehen ist, die innerhalb und außerhalb von Gebäuden und anderen Hoch- und Tiefbauten installiert sind (siehe EN 54 1:2011).
Das nicht-rücksetzbare Sensorelement hat eine feste Temperatur-Alarmschwelle und unterscheidet nicht zwischen Kurzschluss und Alarmzustand.
Diese Europäische Norm legt Anforderungen, Leistungskriterien und die entsprechenden Prüfverfahren fest und stellt die Bewertung und Überprüfung der Leistungsbeständigkeit (AVCP) von nicht-rücksetzbaren linienförmigen Wärmemeldern nach dieser Europäischen Norm zur Verfügung.
Diese Europäische Norm gilt auch für nicht-rücksetzbare linienförmige Wärmemelder, die zur Einrichtungs-überwachung von Anlagen und Einrichtungen vorgesehen sind.
Nicht-rücksetzbare linienförmige Wärmemelder, die spezielle Eigenschaften haben und für Fälle mit besonderen Risiken entwickelt wurden, sind nicht Gegenstand dieser Norm.

Systèmes de détection et d'alarme incendie - Partie 28 : Détecteurs de chaleur de type linéaire non réenclenchables

La présente Norme européenne s'applique aux détecteurs de chaleur de type linéaire non réenclenchables qui comprennent un élément capteur utilisant un câble électrique capteur qui peut être raccordé à une unité de commande, ou de manière directe ou via un module d'interface à un équipement de contrôle et de signalisation, destinés à être utilisés dans les systèmes de détection et d'alarme incendie installés dans et autour des bâtiments et des ouvrages de génie civil (voir l'EN 54 1:2011).
L'élément capteur non réenclenchable a un seuil d'alarme à température fixe et ne fait pas la distinction entre un court-circuit et un état d'alarme.
La présente Norme européenne spécifie les exigences et les critères de performance, les méthodes d'essai correspondantes et prévoit l'évaluation et la vérification de la constance des performances (EVCP) des détecteurs de chaleur de type linéaire non réenclenchables par rapport à la présente Norme européenne.
La présente Norme européenne couvre également les détecteurs de chaleur de type linéaire non réenclenchables destinés à être utilisés pour la protection ponctuelle d’installations et d'équipements.
Les détecteurs de chaleur de type linéaire non réenclenchables possédant des caractéristiques particulières, conçus pour des risques spéciaux, ne sont pas couverts par la présente norme.

Sistemi za odkrivanje in javljanje požara ter alarmiranje - 28. del: Linijski toplotni javljalniki brez ponastavitve

Ta evropski standard se uporablja za linijske toplotne javljalnike brez ponastavitve z elementom za zaznavanje, ki uporablja električen senzorski kabel, ki ga je mogoče priključiti na senzorsko nadzorno enoto ali neposredno ali prek vmesniškega modula na nadzorno in indikatorsko opremo, namenjeno uporabi v sistemih za odkrivanje in javljanje požara ter alarmiranje, vgrajenih v zgradbah in gradbenih inženirskih objektih ter okoli njih (glej standard EN 54 1:2011).
Element za zaznavanje brez ponastavitve ima nastavljeno mejno alarmno vrednost temperature ter ne loči med kratkim stikom in alarmnim stanjem.
Ta evropski standard določa zahteve in merila učinkovitosti, ustrezne preskusne metode ter omogoča ocenjevanje in preverjanje nespremenljivosti zmogljivosti (AVCP) linijskih toplotnih javljalnikov brez ponastavitve v skladu s tem evropskim standardom.
Ta evropski standard zajema tudi linijske toplotne javljalnike brez ponastavitve, namenjene uporabi pri lokalni zaščiti obrata in opreme.
Linijski toplotni javljalniki brez ponastavitve s posebnimi značilnostmi, ki so razviti za posebna tveganja, niso zajeti v tem standardu.

General Information

Status
Published
Public Enquiry End Date
29-Oct-2015
Publication Date
19-Apr-2016
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
25-Feb-2016
Due Date
01-May-2016
Completion Date
20-Apr-2016

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SLOVENSKI STANDARD
SIST EN 54-28:2016
01-maj-2016
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 de type
linéaire non réenclenchables
Ta slovenski standard je istoveten z: EN 54-28:2016
ICS:
13.220.20 3RåDUQD]DãþLWD Fire protection
13.320 Alarmni in opozorilni sistemi Alarm and warning systems
SIST EN 54-28:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 54-28:2016

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SIST EN 54-28:2016


EN 54-28
EUROPEAN STANDARD

NORME EUROPÉENNE

February 2016
EUROPÄISCHE NORM
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 de type linéaire non linienförmige Wärmemelder
réenclenchables
This European Standard was approved by CEN on 13 December 2015.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 54-28:2016 E
worldwide for CEN national Members.

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SIST EN 54-28:2016
EN 54-28:2016 (E)
Contents Page
European foreword . 4
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Abbreviations . 9
4 Product characteristics . 9
4.1 General . 9
4.2 Nominal activation conditions/sensitivity . 9
4.3 Operational reliability . 10
4.4 Tolerance to supply voltage . 12
4.5 Performance parameters under fire condition . 12
4.6 Durability of Performance parameters under fire condition . 12
5 Testing, assessment and sampling methods . 14
5.1 General . 14
5.2 Test procedures nominal activation conditions/sensitivity . 18
5.3 Test procedures operational reliability. 18
5.4 Tolerance to supply parameters . 20
5.5 Performance parameters under fire condition . 20
5.6 Durability of performance parameters under fire condition . 21
6 Assessment and Verification of Constancy of Performance (AVCP) . 38
6.1 General . 38
6.2 Type testing . 38
6.3 Factory Production Control (FPC) . 40
7 Classification and designation . 45
8 Marking, labelling and packaging . 45
8.1 Marking, labelling . 45
8.2 Packaging . 46
Annex A (normative) Mounting of the sensing element of NLTHD in the heat tunnel . 47
A.1 General . 47
A.2 Mounting arrangement of sensing element . 47
Annex B (normative) Heat tunnel for response temperature measurements . 49
B.1 General . 49
B.2 Description of the heat tunnel . 49
Annex C (informative) Construction of the heat tunnel . 50
C.1 General . 50
C.2 Heat tunnel construction . 50
Annex D (normative) Test arrangement for vibration tests for sensing element . 52
2

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EN 54-28:2016 (E)
D.1 General . 52
D.2 Test setup . 52
Annex E (normative) Test apparatus for impact test on the sensing element . 53
E.1 General . 53
E.2 Test apparatus . 53
E.3 Test setup . 53
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the
EU Construction Products Regulation . 56
Bibliography . 66

3

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SIST EN 54-28:2016
EN 54-28:2016 (E)
European foreword
This document (EN 54-28:2016) has been prepared by Technical Committee CEN/TC 72 “Fire detection
and fire alarm systems”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2016, and conflicting national standards shall
be withdrawn at the latest by February 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports the basic requirements of Regulation (EU) 305/2011.
For relationship with EU Regulations, 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 detectors using an optical 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
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SIST EN 54-28:2016
EN 54-28:2016 (E)
— Part 21: Alarm transmission and fault warning routing equipment
— Part 22: Resettable line-type heat detectors
— Part 23: Fire alarm devices – Visual alarm devices
— Part 24: Components of voice alarm systems – Loudspeakers
— Part 25: Components using radio links
— Part 26: Carbon monoxide detectors – Point detectors
— Part 27: Duct smoke detectors
— Part 28: Non-resettable line-type heat 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 fire detectors – 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.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
5

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SIST EN 54-28:2016
EN 54-28:2016 (E)
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 relevant authorities. 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 differentiated by a
type code which reflects the nominal alarm temperature, the tolerance range and the maximum
ambient temperature at which they could be used.
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EN 54-28:2016 (E)
1 Scope
This European Standard applies to non-resettable line-type heat detectors consisting of a sensing
element using an electrical sensor cable which can be connected to a sensor control unit or 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 (see
EN 54-1:2011).
The non-resettable sensing element has a fixed temperature alarm threshold and does not distinguish
between short circuit and alarm condition.
This European Standard specifies the requirements and performance criteria, the corresponding test
methods and provides for the Assessment and Verification of Constancy of Performance (AVCP) of non-
resettable line-type heat detectors to this European Standard.
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.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 54-1:2011, Fire detection and fire alarm systems - Part 1: Introduction
EN 50130-4:2011, Alarm systems - Part 4: Electromagnetic compatibility - Product family standard:
Immunity requirements for components of fire, intruder, hold up, CCTV, access control and social alarm
systems
EN 60068-1:2014, Environmental testing - Part 1: General and guidance (IEC 60068-1:2013)
EN 60068-2-1:2007, Environmental testing - Part 2-1: Tests - Test A: Cold (IEC 60068-2-1:2007)
EN 60068-2-2:2007, Environmental testing - Part 2-2: Tests - Test B: Dry heat (IEC 60068-2-2:2007)
EN 60068-2-27:2009, Environmental testing - Part 2-27: Tests - Test Ea and guidance: Shock (IEC 60068-
2-27:2009)
EN 60068-2-30:2005, Environmental testing - Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h
cycle) (IEC 60068-2-30:2005)
EN 60068-2-42:2003, Environmental testing - Part 2-42: Tests - Test Kc: Sulphur dioxide test for contacts
and connections (IEC 60068-2-42:2003)
EN 60068-2-6:2008, Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal) (IEC 60068-
2-6:2008)
EN 60068-2-75:1997, Environmental testing - Part 2-75: Tests - Test Eh: Hammer tests (IEC 60068-2-
75:1997)
EN 60068-2-78:2013, Environmental testing - Part 2-78: Tests - Test Cab: Damp heat, steady state
(IEC 60068-2-78:2012)
7

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EN 54-28:2016 (E)
3 Terms, definitions and abbreviations
For the purposes of this document, the terms and definitions given in EN 54-1:2011 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 1 to entry: 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
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).
3.1.4
non-resettable line-type heat detectors
NLTHD
detector which responds to heat sensed in the vicinity of a continuous line, and which can only respond
once
Note 1 to entry: A non-resettable line-type heat detector may consist of a sensor control unit, a sensing element
and functional units.
3.1.5
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 to entry: A sensing element may consist of different segments separated, e.g. by functional units or
splices.
Note 2 to entry: 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 3.1.6).
3.1.6
sensor control unit
unit that supervises the sensing element and communicates to the control and indicating equipment
Note 1 to entry: The unit can be remote or an integral part of the control and indicating equipment as defined
by EN 54–2.
8

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3.2 Abbreviations
For the purposes of this document, the following abbreviation applies.
NLTHD: non-resettable line-type heat detector
4 Product characteristics
4.1 General
4.1.1 Compliance
In order to comply with the present standard, detectors NLTHD shall comply with the requirements of
Clause 4, which shall be verified by visual inspection or engineering assessment as described in Clause 5
and shall meet the requirements of the tests.
4.1.2 NLTHD performance type
To simplify/standardize/rationalize product marking (see Clause 8), the performance type of the
NLTHD is described using the following format, Txxx-Vyy-Azzz, where:
— Txxx is the nominal alarm temperature in the range 54 °C to 160 °C;
— Vyy is the variance of the nominal alarm temperature in ± %, which is either 05 or 10;
— Azzz is 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 NLTHD 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 is to
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 an NLTHD:
The sensing element is in either environmental group II or III.
The sensor control unit and the functional unit are in 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 outdoors.
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
9

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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.
To confirm this, the detector shall be assessed in accordance with 5.2.1.
4.2.2 Signalling
The NLTHD 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.
To confirm this, the detector shall be assessed in accordance with 5.2.2.
4.3 Operational reliability
4.3.1 Maximum ambient temperature
The sensing element of the NLTHD shall be capable of withstanding long term exposure to
temperatures as specified in 5.3.1.
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.
Where such connections are present the detector shall be assessed in accordance with 5.3.2.
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).
To confirm this, the detector shall be assessed in accordance with 5.3.3.
4.3.4 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,
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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.
To confirm this, the detector shall be assessed in accordance with 5.3.4.
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4.3.5 Sensing element fault
The NLTHD shall signal a fault condition when the sensing element is interrupted.
To confirm this, the detector shall be assessed in accordance with 5.3.5.
4.3.6 On-site adjustment of response 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.
These adjustments may be carried out at the sensor control unit or at the control and indicating
equipment.
To confirm this, the detector shall be assessed in accordance with 5.3.6.
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 5.4.1.
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 5.4.2.
4.5 Performance parameters under fire condition
The response temperature of the tested NLTHD's shall be within the manufacturer's performance type
declaration as specified in 5.5.
4.6 Durability of Performance param
...

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