IEC 60364-4-42:2010

IEC 60364-4-42 ®
Edition 3.0 2010-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
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IEC 60364-4-42 ®
Edition 3.0 2010-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
S
CODE PRIX
ICS 29.120.50; 91.140.50 ISBN 978-2-88910-942-5
– 2 – 60364-4-42 © IEC:2010
CONTENTS
FOREWORD.3
420.1 Scope .5
420.2 Normative references .5
420.3 Terms and definitions.5
421 Protection against fire caused by electrical equipment .6
421.1 General requirements .6
422 Precautions where particular risks of fire exist.8
422.1 General .8
422.2 Conditions of evacuation in an emergency.8
422.3 Locations with risks of fire due to the nature of processed or stored
materials .9
422.4 Locations with combustible constructional materials .11
422.5 Fire propagating structures.12
422.6 Selection and erection of installations in locations with endangering
of irreplaceable goods .12
423 Protection against burns .13
424 Protection against overheating .13
424.1 Forced air heating systems.13
424.2 Appliances producing hot water or steam .13
424.3 Space heating appliances.14
Annex A (informative) List of notes concerning certain countries.15
Bibliography.19

Table 42.1 – Temperature limits in normal service for accessible parts of equipment
within arm’s reach.13

60364-4-42 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 4-42: Protection for safety –
Protection against thermal effects

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60364-4-42 has been prepared by IEC technical committee 64:
Electrical installations and protection against electric shock.
This third edition cancels and replaces the second edition, published in 2001, and constitutes
a technical revision.
The main changes with respect to the previous edition are listed below:
– The scope now includes protection against all thermal effects and flames in case of a fire
hazard being propagated from electrical installations to other fire compartments
segregated by barriers which are in the vicinity.
– Requirements associated with escape routes for evacuation in an emergency have been
expanded/modified.
– Requirements associated with the nature of processed or stored materials have been
expanded/modified.
– 4 – 60364-4-42 © IEC:2010
– Requirements associated with combustible constructional materials have been
expanded/modified.
– Requirements associated with fire propagating structures have been modified slightly.
– New requirements for the selection and erection of installations in locations which might
endanger precious goods have been added.
– Protection against overheating now includes space heating appliances.
The text of this standard is based on the following documents:
FDIS Report on voting
64/1725/FDIS 64/1729/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The reader's attention is drawn to the fact that Annex A lists all of the "in-some-country"
clauses on differing practices of a less permanent nature relating to the subject of this
standard.
A list of all parts in the IEC 60364 series, under the general title Low-voltage electrical
installations, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60364-4-42 © IEC:2010 – 5 –
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 4-42: Protection for safety –
Protection against thermal effects

420.1 Scope
This part of IEC 60364 applies to electrical installations with regard to measures for the
protection of persons, livestock and property against
– thermal effects, combustion or degradation of materials, and risk of burns caused by
electrical equipment,
– flames in case of a fire hazard being propagated from electrical installations to other fire
compartments segregated by barriers which are in the vicinity, and
– the impairment of the safe functioning of electrical equipment including safety services.
NOTE 1 For protection against thermal effects, national statutory requirements may be applicable.
NOTE 2 Protection against overcurrent is dealt with in IEC 60364-4-43.
420.2 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.
IEC 60332 (all parts), Tests on electric and optical fibre cables under fire conditions
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60364-5-51:2005, Electrical installations of buildings – Part 5-51: Selection and erection
of electrical equipment – Common rules
IEC 61084 (all parts), Cable trunking and ducting systems for electrical installations
IEC 61386 (all parts), Conduit systems for cable management
IEC 61534 (all parts), Power track systems
IEC 61537, Cable management – Cable tray systems and cable ladder systems
IEC 60598-2-24, Luminaires – Part 2-24: Particular requirements – Luminaires with limited
surface temperatures
420.3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

– 6 – 60364-4-42 © IEC:2010
420.3.1
combustible
capable of burning
420.3.2
fire
– a process of combustion characterized by the emission of heat and effluent accompanied
by smoke, and/or flame and/or glowing
– rapid combustion spreading uncontrolled in time and space
420.3.3
flammability
ability of a material or product to burn with a flame under specified test conditions
420.3.4
ignitability
measure of the ease with which a specimen can be ignited due to the influence of an external
source, under specified test conditions
420.3.5
ignition
initiation of combustion
NOTE For more information see IEC 60695-4.
420.3.6
non-flame propagating component
component which is liable to ignite, as a result of an applied flame, but in which the flame
does not propagate and which extinguishes itself within a limited time after the flame is
removed
[IEC 60050-442:1998, 442-01-12]
421 Protection against fire caused by electrical equipment
421.1 General requirements
Persons, livestock and property shall be protected against damage or injury caused by heat or
fire which may be generated or propagated in electrical installations by taking into account the
requirements of this standard and the instructions of equipment manufacturers.
The heat generated by electrical equipment shall not cause danger or harmful effects to
adjacent fixed material or to material which may foreseeably be in proximity to such
equipment. Electrical equipment shall not present a fire hazard to adjacent materials.
NOTE Damage, injury or ignition may be caused by effects such as
– heat accumulation, heat radiation, hot elements,
– reduction of the safe function of electrical equipment, e.g. protective devices such as protective switchgear,
thermostats, temperature limiters, seals of cable penetrations and wiring systems,
– overcurrent,
– insulation faults and/or arcs causing interference,
– harmonic currents,
– lightning strikes, see the IEC 62305 series,
– overvoltages, see Clause 443 of IEC 60364-4-44:2007,
– inappropriate selection or erection of equipment.
Any relevant manufacturer’s erection instructions shall be taken into account in addition to the
requirements of the IEC 60364 series.

60364-4-42 © IEC:2010 – 7 –
421.2 Where fixed equipment may attain surface temperatures which could cause a fire
hazard to adjacent materials, the equipment shall either
• be mounted on or within materials that will withstand such temperatures and are of low
thermal conductance, or
• be screened from elements of building construction by materials which will withstand such
temperatures and are of low thermal conductance, or
• be mounted so as to allow safe dissipation of heat at a sufficient distance from any
material on which such temperatures could have deleterious thermal effects, any means of
support being of low thermal conductance.
421.3 Where arcs or sparks may be emitted by permanently connected equipment in normal
service, the equipment shall either
• be totally enclosed in arc-resistant material, or
• be screened by arc-resistant material from materials on which the emission could have
harmful effects, or
• be mounted so as to allow safe extinction of the emissions at a sufficient distance from
material upon which the emissions could have harmful effects.
Arc-resistant material used for this protective measure shall be non-ignitable, of low thermal
conductivity, and of adequate thickness to provide mechanical stability.
NOTE For example, a sheet made of fibreglass silicone of 20 mm thickness may be considered as arc-resistant.
421.4 Fixed equipment causing a concentration of heat shall be at a sufficient distance from
any fixed object or building element so that the object or element, in normal conditions, is not
subjected to a dangerous temperature. For example, a temperature in excess of its ignition
temperature.
NOTE Any information from the manufacturer of the equipment should be taken into account.
421.5 Where electrical equipment in a single location contains flammable liquid in significant
quantity, adequate precautions shall be taken to prevent the spread of liquid, flame and the
products of combustion.
NOTE 1 Examples of such precautions include:
• a retention pit to collect any leakage of liquid and ensure extinction in the event of fire;
• installation of the equipment in a chamber of adequate fire resistance and the provision of sills or other means
of preventing liquid spreading to other parts of the building, such a chamber being ventilated solely to the
external atmosphere.
NOTE 2 The generally accepted lower limit for a significant quantity is 25 l.
NOTE 3 For quantities less than 25 l, it is sufficient to take precautions to prevent the escape of liquid.
NOTE 4 Products of combustion of liquid are considered to be flame, smoke and gas.
NOTE 5 It is desirable to switch off the supply at the onset of a fire.
421.6 The materials of enclosures installed around electrical equipment during erection shall
withstand the highest temperature likely to be produced by the electrical equipment.
Combustible materials are not suitable for the construction of these enclosures unless
preventive measures against ignition are taken, such as covering with non-combustible or not
readily combustible material of low thermal conductivity.

– 8 – 60364-4-42 © IEC:2010
422 Precautions where particular risks of fire exist
422.1 General
422.1.1 Electrical equipment shall be restricted to that necessary for the use of these
locations, except wiring systems according to 422.3.5.
422.1.2 Electrical equipment shall be so selected and erected that its temperature in normal
use and foreseeable temperature rise during a fault cannot cause a fire.
These arrangements may be effected by the construction of equipment or its conditions of
installation.
Special measures are not necessary where the temperature of surfaces is unlikely to cause
ignition of nearby substances.
422.1.3 Thermal cut-out devices shall have manual resetting only.
422.2 Conditions of evacuation in an emergency
Condition BD2: Low density occupation, difficult conditions of evacuation
BD3: High density occupation, easy conditions of evacuation
BD4: High density occupation, difficult conditions of evacuation
(according to Table 51A of IEC 60364-5-51:2005).
NOTE Authorities responsible for building construction, public gatherings, fire prevention, etc. may specify which
BD condition is applicable.
422.2.1 In conditions BD2, BD3 and BD4, wiring systems shall not encroach on escape
routes unless the wiring in the wiring system is provided with sheaths or enclosures, provided
by the cable management system itself or by other means.
Wiring systems encroaching on escape routes shall not be within arm's reach unless they are
provided with protection against mechanical damage likely to occur during an evacuation.
Wiring systems in escape routes shall be as short as practicable and shall be non-flame
propagating.
NOTE 1 Compliance with this requirement may be achieved by using the following products:
– cables fulfilling tests under fire conditions of IEC 60332-1-2, and appropriate fire conditions as follows:
IEC 60332-3-21, IEC 60332-3-22, IEC 60332-3-23, IEC 60332-3-24 and IEC 60332-3-25;
– conduit systems classified as non-flame propagating according to IEC 61386-1;
– cable trunking systems classified as non-flame propagating according to IEC 61084-1;
– cable tray systems and cable ladder systems classified as non-flame propagating according to IEC 61537;
– for powertrack systems: the IEC 61534 series.
In conditions BD2, BD3 and BD4, wiring systems that are supplying safety circuits shall have
a resistance to fire rating of either the time authorized by regulations for building elements or
1 h in the absence of such a regulation.
NOTE 2 For the requirements for maintaining the function of wiring systems of safety services under fire
conditions, refer to Part 56.
Wiring within escape routes shall have a limited rate of smoke production.
NOTE 3 In the absence of any detailed requirement provided by cable standards, it is recommended that a value
of 60 % light transmittance is adopted as a minimum for any cable tested against IEC 61034-2.
422.2.2 In conditions BD2, BD3 and BD4, switchgear and controlgear devices, except
certain devices to facilitate evacuation, shall be accessible only to authorized persons. If they

60364-4-42 © IEC:2010 – 9 –
are placed in passages, they shall be enclosed in cabinets or boxes constructed of non-
combustible or not readily combustible material.
NOTE This clause does not prohibit plastic enclosures that are not readily combustible.
422.2.3 In conditions BD3 and BD4 and in escape routes, electrical equipment containing
flammable liquids shall not be installed.
NOTE Individual capacitors incorporated in equipment are not subject to this requirement. This exception
principally concerns discharge luminaires and capacitors of motor starters.
422.3 Locations with risks of fire due to the nature of processed or stored
materials
Condition BE2: Fire risk (according to Table 51A of IEC 60364-5-51:2005).
NOTE 1 Quantities of flammable materials or the surface or volume of the location may be regulated by national
authorities.
NOTE 2 For explosion risks, see IEC 60079-14.
422.3.1 Luminaires shall be kept at an adequate distance from combustible materials. If no
other information is given by manufacturers, spotlights and projectors shall be installed at the
following minimum distances from combustible materials:
≤ 100 W 0,5 m
> 100 W to 300 W 0,8 m
> 300 W to 500 W 1,0 m
> 500 W greater distances can be necessary.
NOTE In the absence of manufacturers’ instructions, the above distances imply all directions.
Lamps and other components of luminaires shall be protected against foreseeable mechanical
stresses. Such protective means shall not be fixed on lampholders unless they form an
integral part of the luminaire. Modifications to luminaires are not acceptable.
A luminaire with a lamp that could eject flammable materials in case of failure shall be
installed with a safety protective shield for the lamp in accordance with the manufacturer’s
instructions.
NOTE Luminaires suitable for direct mounting on normally flammable surfaces were earlier marked with the
symbol
according to IEC 60598-1:2003 (sixth edition).
1)
With the publication of IEC 60598-1:2008 , luminaires suitable for direct mounting have no special marking and
only luminaires not suitable for mounting on normally flammable surfaces are marked with symbols
and/or
(see Clause N.4 of IEC 60598-1:2008 for further explanations).
———————
1)
This seventh edition cancelled and replaced the sixth edition.

– 10 – 60364-4-42 © IEC:2010
422.3.2 Measures shall be taken to prevent an electrical enclosure of equipment such as a heater or
resistor from exceeding the following temperatures:
• 90 °C under normal conditions, and
• 115 °C under fault conditions.
Where materials such as dust or fibres sufficient to cause a fire hazard could accumulate on
an enclosure of electrical equipment, adequate measures shall be taken to prevent that
enclosure from exceeding the temperatures stated above.
NOTE Luminaires marked in compliance with IEC 60598-2-24 are designed to provide limited surface
temperature.
422.3.3 Switchgear for protection, control and isolation shall be placed outside locations
presenting condition BE2, unless it is in an enclosure providing a degree of protection
appropriate for such a location of at least IP4X or, in the presence of dust, IP5X or, in the
presence of conductive dust, IP6X, except where 422.3.11 applies.
422.3.4 Except where wiring and wiring systems are embedded in non-combustible material,
only non-flame-propagating wiring systems shall be used.
As a minimum, equipment shall be selected in accordance with the following requirements:
– cables shall satisfy the test under fire conditions specified in the IEC 60332 series;
– conduit systems shall satisfy the test for resistance to flame propagation specified in the
IEC 61386 series;
– cable trunking systems and cable ducting systems shall satisfy the test for resistance to
flame propagation specified in the IEC 61084 series;
– cable tray systems and cable ladder systems shall satisfy the test for resistance to flame
propagation specified in the IEC 61537 series;
– powertrack systems shall satisfy the test for resistance to flame propagation specified in
the IEC 61534 series.
NOTE 1 Where the risk of flame propagation is high, e.g. in long vertical runs of bunched cables, cables should
meet the flame propagation characteristics of the appropriate part in the IEC 60332-3 series.
NOTE 2 Flame propagation tests for cable management systems are always performed in a vertical configuration.
422.3.5 Wiring systems which traverse these locations, but are not necessary for the use of
the locations, shall satisfy the following conditions:
• the wiring systems shall meet the requirements of 422.3.4;
• they have no connection along the route inside the locations, unless these connections
are placed in fire-resistant enclosures;
• they are protected against overcurrent in accordance with 422.3.10;
• bare conductors shall not be used.
422.3.6 In forced-air heating installations, the air intake shall be outside locations where a
presence of combustible dust may be expected.
The temperature of the outgoing air shall not be such as to cause fire in the location.
422.3.7 Motors which are automatically or remotely controlled, or which are not continuously
supervised, shall be protected against excessive temperature rise by temperature responsive
devices, unless specifically designed to be inherently heat-limiting.
422.3.8 Every luminaire shall
• be appropriate for the location, and

60364-4-42 © IEC:2010 – 11 –
• be provided with an enclosure providing a degree of protection of at least IP4X or, in the
presence of dust, IP5X or, in the presence of conductive dust, IP6X, and
• have a limited surface temperature in accordance with IEC 60598-2-24, and
• be of a type that prevents lamp components from falling from the luminaire.
In locations where there may be fire hazards due to dust or fibres, luminaires shall be
installed so that dust or fibres cannot accumulate in dangerous amounts.
NOTE Luminaires should also comply with relevant parts of the IEC 60598 series. See also Clause 559 of
IEC 60364-5-55:2001.
422.3.9 Final circuits and current-using equipment shall be protected against insulation
faults as follows:
a) In TN and TT systems, RCDs with a rated residual operating current I ≤300 mA shall be
∆n
used. Where resistive faults may cause a fire, e.g. for overhead heating with heating film
elements, the rated residual operating current shall be I ≤30 mA.
∆n
b) In IT systems, insulation monitoring devices monitoring the whole installation or RCMs
(residual current monitoring devices) in the final circuits, both with audible and visual
signals, shall be provided. Alternatively, RCDs with a rated residual operating current as
specified in a) may be used. In the event of a second fault see Part 41 for disconnection
times.
Mineral insulated cables and busbar trunking systems are not considered likely to cause a fire
from insulation faults and therefore need not be protected.
NOTE Cables with metallic coverings are recommended. The metallic covering should be connected to the
protective conductor.
422.3.10 Circuits supplying or traversing locations where condition BE2 applies, shall be
protected against overload and short-circuit by protective devices located outside and on the
supply side of these locations. Circuits originating inside the locations shall be protected
against overcurrent by protective devices located at their origin.
422.3.11 In circuits supplied at SELV or PELV, live parts shall be
• contained in enclosures affording the degree of protection IP2X or IPXXB, or
• provided with insulation capable of withstanding a test voltage of 500 V d.c. for 1 min.
regardless of the nominal voltage of the circuit. This is in addition to the requirements of
414.4.5 of IEC 60364-4-41:2005.
422.3.12 PEN conductors are not allowed in locations where condition BE2 applies, except
for circuits traversing such locations and having no connection between their traversing PEN
conductor and any conductive part in the locations.
422.3.13 Every circuit supplying equipment in locations where condition BE2 applies shall be
provided with a means of isolation from all live supply conductors such that no live supply
conductor can remain closed when one or more others are open. This may be achieved, for
example, by a mechanically linked switch or a mechanically linked circuit-breaker.
NOTE Provision may be made for isolation of a group of circuits by a common means, if the service conditions
allow this.
422.4 Locations with combustible constructional materials
Condition CA2: Combustible materials (according to Table 51A of IEC 60364-5-51:2005).

– 12 – 60364-4-42 © IEC:2010
422.4.1 Precautions shall be taken to ensure that electrical equipment cannot cause the
ignition of walls, floors or ceilings. This can be achieved by proper design, choice and
installation of electrical equipment.
To avoid the ingress of solid foreign objects, boxes and enclosures installed in prefabricated
hollow walls liable to be drilled during erection of the wall shall have a degree of protection of
at least IP3X.
422.4.2 Luminaires shall be kept at an adequate distance from combustible materials. If no
other information is given by manufacturers, spotlights and projectors shall be installed at the
following minimum distances from combustible materials:
≤ 100 W 0,5 m
> 100 W to 300 W 0,8 m
> 300 W to 500 W 1,0 m
> 500 W greater distances can be necessary.
NOTE 1 In the absence of manufacturers’ instructions, the above distances imply all directions.
Lamps and other components of luminaires shall be protected against foreseeable mechanical
stresses. Such protective means shall not be fixed on lampholders, unless they form an
integral part of the luminaire.
A luminaire with a lamp that could eject flammable materials in case of failure shall be
installed with a safety protective shield for the lamp in accordance with the manufacturer’s
instructions.
NOTE 2 Luminaires suitable for direct mounting on normally flammable surfaces were earlier marked with the
symbol
according to IEC 60598-1:2003 (sixth edition).
With the publication of IEC 60598-1:2008, luminaires suitable for direct mounting have no special marking and only
luminaires not suitable for mounting on normally flammable surfaces are marked with symbols
and/or
(see Clause N.4 of IEC 60598-1:2008 for further explanations).
422.5 Fire propagating structures
Condition CB2: Propagation of fire (according to Table 51A of 60364-5-51:2005).
422.5.1 In structures where the shape and dimensions facilitate the spread of fire,
precautions shall be taken to ensure that the electrical installation cannot propagate a fire
(e.g. chimney effect).
NOTE Fire detectors may be provided which ensure the implementation of measures for preventing propagation
of fire, for example, the closing of fire-proof shutters in ducts, building voids and the like. Boxes and enclosures
according to IEC 60670-1 for hollow walls and cables in accordance with the IEC 60332-3 series can be used.
IEC 60670-1 includes marking with the symbol H for boxes and enclosures for hollow walls.
422.6 Selection and erection of installations in locations with endangering of
irreplaceable goods
The requirements of 422.1.2 shall be met.

60364-4-42 © IEC:2010 – 13 –
NOTE 1 The locations include buildings or rooms with assets of significant value.
Examples include: national monuments, museums and other public buildings. Buildings such as railway stations
and airports, buildings or facilities such as laboratories, computer centres and certain industrial and storage
facilities.
NOTE 2 The following measures may be considered:
– installation of mineral insulated cables according to IEC 60702-1;
– installation of cables with improved fire-resisting characteristics in case of a fire hazard, and complying with
IEC 60331-1 or IEC 60331-21 or similar;
– installation of cables in non-combustible solid walls, ceilings and floors;
– installation of cables in areas with constructional partitions having a fire-resisting capability for a time of
30 min or 90 min, the latter in locations housing staircases and needed for an emergency escape.
Where these measures are not practicable, enhanced fire protection may be possible by use of reactive fire
protection systems.
423 Protection against burns
Accessible parts of electrical equipment within arm’s reach shall not attain a temperature
likely to cause burns to persons, and shall comply with the appropriate limit stated in
Table 42.1. All parts of the installation likely in normal service to attain, even for short
periods, temperatures exceeding the limits stated in Table 42.1 shall be guarded so as to
prevent any accidental contact. However, the values in Table 42.1 do not apply to equipment
complying with IEC standards for the type of equipment concerned.
NOTE Lower temperatures may be applicable where condition BA2 (children) applies.
Table 42.1 – Temperature limits in normal service for accessible
parts of equipment within arm’s reach
Accessible parts Material of Maximum
accessible surfaces temperatures
°C
Hand-held means of operation Metallic 55
Non-metallic 65
Parts intended to be touched but not Metallic 70
hand-held
Non-metallic 80
Parts which need not be touched for Metallic 80
normal operation
Non-metallic 90
424 Protection against overheating
424.1 Forced air heating systems
Forced air heating systems shall be such that their heating elements, other than those of
central storage heaters, cannot be activated until the prescribed air flow has been established
and are deactivated when the air flow is less than the prescribed value. In addition, they shall
have two temperature limiting devices independent of each other which prevent permissible
temperatures from being exceeded in air ducts.
Supporting parts, frames and enclosures of heating elements shall be of non-combustible
material.
424.2 Appliances producing hot water or steam
All appliances producing hot water or steam shall be protected by design or erection against
overheating in all service conditions. Unless the appliances comply as a whole with the

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appropriate IEC standards, the protection shall be by means of an appropriate non-self-
resetting device, functioning independently of the thermostat.
If an appliance has no free outlet, it shall also be provided with a device which limits the
internal water pressure.
424.3 Space heating appliances
The frame and enclosure of space heating appliances shall be of non-combustible material.
NOTE In operating areas with a fire risk, space heating appliances may not be operated if the air from these
areas is guided through the appliance.
The side walls of radiant heaters which are not touched by the heat radiation should have a sufficient distance from
flammable parts. In case of a reduction of the distance by a non-flammable partition, this partition should have a
distance of at least 1 cm to the enclosure of the radiant heater and to flammable parts.
Unless otherwise declared by the manufacturer, radiant heaters should be mounted so that in the direction of
radiation a safety distance of at least 2 m from flammable parts is ensured.

60364-4-42 © IEC:2010 – 15 –
Annex A
(informative)
List of notes concerning certain countries

Country Clause Text
Czech 422.3.9 Replace the introduction to items a) and b) with the following:
Republic
“Final circuits and current-using equipment, with the exception of
wiring systems enclosed in enclosures having degree of protection at least IP4X, shall be
protected against insulation faults as follows:”
Germany 420.1 In Germany, the following additional requirements to the scope apply to the second
indent of 420.1:
– against flames and smoke in case of a fire hazard being propagated from electrical
installations to other fire compartments segregated by barriers which are in the
vicinity, and
DE 421.3 In Germany, the following additional requirements for protection against arcing apply:
Protective devices should be installed for protection in case of arcing where the
electrical installation shall meet a high degree of reliability.
Protective devices for the protection against arcing shall detect the light effect of the
arc and the increase of current in the line conductors. Furthermore, they shall
extinguish the arc within a time of 5 ms and disconnect the electrical installation from
the supply. The extinguishing of the arc may not be generated before the set limiting
values regarding the light and current detection are exceeded.
Slowly acting protective devices are not able to prevent damage of goods and that
can make it impossible to put the electrical installation in to operation again within a
short time.
In general a separation by use of a metal sheet does not provide the required arc
withstand capability.
DE 421.7 In Germany the following additional requirements apply :
Where in case of a fire hazard from switchgear assemblies heavy smoke generation
in escape corridors may be assumed a sealed fire barrier for the erection of the
switchgear assembly is necessary.
This requirement is fulfilled if the switchgear assembly is placed in an enclosure of
non- combustible material or in a separate location. Ceilings and walls of the
separating location shall have a fire-resisting capability for a time of at least 90 min
and doors for a time of at least 30 min.
DE 422.2 In Germany, the following additional requirements for escape routes apply:
For wiring in escape routes there are special conditions established by federal state
authorities on the basis of the Muster-Richtlinie über brandschutztechnische
Anforderungen an Leitungsanlagen (Muster- Leitungsanlagen-Richtlinien MLAR).
DE 422.3 In Germany the following additional requirements apply:
Subclause 422.3 includes, for example, the selection and erection of installations in
locations with risk of fire due to the nature of processed or stored materials such as
the place chosen for manufacturing, processing, storage of combustible materials,
including the accumulation of dust in barns, wood working factories, paper mills,
textile factories or similar.
NOTE The nature and allowed quantities of combustible materials, or surface or volume of the locations may
be regulated by national authorities
DE 422.3.1 In Germany the following additional requirements apply:
Luminaires marked D in accordance with IEC 60598-1 are suitable for mounting on
normally flammable surfaces. For luminaires marked with the symbol D protection
against deposition of dust and other substances shall be provided also inside the
luminaire. For compliance with this requirement the luminaire is covered in the
direction of the spot light with a protective glass cover or a tube of IP5X.
DE 422.3.9 a) In Germany the following additional requirement applies to 422.3.9 a)
NOTE 1 This requirement is generally fulfilled if the disconnection occurs in a time not exceeding 5 s. In
electrical installations with a rated voltage 230/ 400V AC for this purpose RCD with a rated residual operating
current not exceeding 300 mA are used.
NOTE 2 In the case of panel heating systems this requirement is fulfilled if the disconnection occurs at a

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Country Clause Text
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