SIST EN 62395-1:2014

SLOVENSKI STANDARD
01-marec-2014
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SIST EN 62395-1:2007
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Electrical resistance trace heating systems for industrial and commercial applications -
Part 1: General and testing requirements
/
Systèmes de traçage par résistance électrique pour applications industrielles et
commerciales - Partie 1: Exigences générales et d'essai
Ta slovenski standard je istoveten z: EN 62395-1:2013
ICS:
25.180.10 (OHNWULþQHSHþL Electric furnaces
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62395-1
NORME EUROPÉENNE
December 2013
EUROPÄISCHE NORM
ICS 25.180.10 Supersedes EN 62395-1:2006

English version
Electrical resistance trace heating systems for industrial
and commercial applications -
Part 1: General and testing requirements
(IEC 62395-1:2013)
Systèmes de traçage par résistance Elektrische Widerstands-Begleitheizungen
électrique pour applications industrielles für industrielle und gewerbliche Zwecke -
et commerciales - Teil 1: Allgemeine Anforderungen und
Partie 1: Exigences générales et d'essai Prüfanforderungen
(CEI 62395-1:2013) (IEC 62395-1:2013)

This European Standard was approved by CENELEC on 2013-10-14. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified
to the CEN-CENELEC Management Centre has the same status as the official versions.

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

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62395-1:2013 E
Foreword
The text of document 27/926/FDIS, future edition 2 of IEC 62395-1, prepared by IEC/TC 27 "Industrial
electroheating and electromagnetic processing" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 62395-1:2013.

The following dates are fixed:
(dop) 2014-07-14
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2016-10-14
standards conflicting with the
document have to be withdrawn
This document supersedes EN 62395-1:2006.

EN 62395-1:2006:
- tests have been added for trace heating on sprinkler systems;
- the flammability test has been changed to align with the latest draft of future
1)
IEC/IEEE 60079-30-1 ;
- a supplementary test has been added for the verification of sheath temperature using trace heating
mounted on a plate fixture.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This standard covers the Principle Elements of the Safety Objectives for Electrical Equipment
Designed for Use within Certain Voltage Limits (LVD - 2006/95/EC).

Endorsement notice
The text of the International Standard IEC 62395-1:2013 was approved by CENELEC as a European
Standard without any modification.

1)
Under consideration.
- 3 - EN 62395-1:2013
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60068-2-5 - Environmental testing - EN 60068-2-5 -
Part 2-5: Tests - Test Sa: Simulated solar
radiation at ground level and guidance for
solar radiation testing
IEC 60519-1 - Safety in electroheating installations - EN 60519-1 -
Part 1: General requirements
IEC 60519-10 - Safety in electroheating installations - EN 60519-10 -
Part 10: Particular requirements for electrical
resistance trace heating systems for
industrial and commercial applications

IEC 62395-2 2013 Electrical resistance trace heating systems EN 62395-2 2013
for industrial and commercial applications -
Part 2: Application guide for system design,
installation and maintenance
ASTM D 5025-05 - Standard Specification for Laboratory Burner
Used for Small-Scale Burning Tests on
Plastic Materials
ASTM D 5207-09 - Standard Practice for Confirmation of 20-mm
(50-W) and 125-mm (500-W) Test Flames
for Small-Scale Burning Tests on Plastic
Materials
IEC 62395-1 ®
Edition 2.0 2013-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical resistance trace heating systems for industrial and commercial

applications –
Part 1: General and testing requirements

Systèmes de traçage par résistance électrique pour applications industrielles et

commerciales –
Partie 1: Exigences générales et d'essai

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 25.180.10 ISBN 978-2-8322-1079-6

– 2 – 62395-1 © IEC:2013
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 General requirements . 13
4.1 General . 13
4.2 Electrically conductive covering . 13
4.3 Electrical circuit protection requirements for branch circuits . 13
4.4 Temperature requirements . 14
4.4.1 General . 14
4.4.2 Stabilized design . 14
4.4.3 Controlled design . 14
5 Testing . 14
5.1 Type tests – General . 14
5.2 Type tests – All applications . 14
5.2.1 Dielectric test . 14
5.2.2 Electrical insulation resistance test . 15
5.2.3 Flammability test . 16
5.2.4 Room temperature impact test . 17
5.2.5 Minimum temperature impact test . 19
5.2.6 Deformation test . 20
5.2.7 Cold bend test . 21
5.2.8 Water resistance test . 22
5.2.9 Integral components resistance to water test . 22
5.2.10 Verification of rated output . 23
5.2.11 Thermal stability of electrical insulating material . 25
5.2.12 Thermal performance test for parallel trace heaters . 26
5.2.13 Determination of maximum sheath temperature . 27
5.2.14 Verification of start-up current . 34
5.2.15 Verification of the electrical resistance of the electrically conductive
covering . 34
5.2.16 Strain relief test for connections (terminations) . 34
5.3 Type tests – Additional tests for outdoor exposed surface heating
installations without thermal insulation . 35
5.3.1 Verification of rated output . 35
5.3.2 Determination of maximum sheath temperature . 35
5.3.3 Increased moisture resistance test . 35
5.3.4 UV test . 35
5.3.5 Resistance to cutting test . 35
5.3.6 Abrasion test . 35
5.3.7 Tension test . 36
5.3.8 Rail system voltage spike test . 36
5.3.9 Rail system over-voltage test . 37
5.4 Type tests – Additional tests and test modifications for embedded heating
applications . 37
5.4.1 Verification of rated output . 37

62395-1 © IEC:2013 – 3 –
5.4.2 Determination of maximum sheath temperature . 37
5.4.3 Resistance to cutting test . 37
5.4.4 Flammability test . 37
5.5 Type tests – Additional tests for applications of trace heating internal to
conduit and piping . 37
5.5.1 Verification of rated output . 37
5.5.2 Determination of maximum sheath temperature . 37
5.5.3 Increased moisture resistance test . 37
5.5.4 Pull-strength test . 38
5.6 Type tests – Additional requirements for sprinkler systems . 38
5.6.1 Normal and abnormal operation test . 38
5.6.2 Normal operation test . 38
5.6.3 Abnormal operation test . 41
5.7 Routine tests . 41
5.7.1 Dielectric test . 41
5.7.2 Verification of rated output . 41
6 Marking . 41
6.1 General . 41
6.2 Product markings . 42
7 Installation instructions . 42
Bibliography . 44

Figure 1 – Flammability test . 17
Figure 2 – Room temperature impact test . 18
Figure 3 – Example of room temperature impact test apparatus . 19
Figure 4 – Example of minimum temperature impact test apparatus . 20
Figure 5 – Cold bend test . 22
Figure 6 – Moisture resistance test . 23
Figure 7 – Verification of rated output . 25
Figure 8 – Pipe fixture. 29
Figure 9 – Plate fixture. 30
Figure 10 – Plate fixture when trace heaters are allowed to touch . 31
Figure 11 – Maximum sheath temperature using the product approach . 34
Figure 12 – Abrasion test . 36
Figure 13 – Sprinkler system temperature control test – branch line arrangement . 39
Figure 14 – Sprinkler system temperature control test – branch line – alternative
arrangement . 40
Figure 15 – Sprinkler system temperature control test – supply pipe arrangement . 40

Table 1 – Test voltages for the dielectric test . 15
Table 2 – Product marking . 42

– 4 – 62395-1 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL RESISTANCE TRACE HEATING SYSTEMS
FOR INDUSTRIAL AND COMMERCIAL APPLICATIONS –

Part 1: General and testing requirements

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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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 62395-1 has been prepared by IEC technical committee 27:
Industrial electroheating and electromagnetic processing.
This second edition cancels and replaces the previous edition published in 2006 and
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– Tests have been added for trace heating on sprinkler systems;
– The flammability test has been changed to align with the latest draft of future
IEC/IEEE 60079-30-1 ;
—————————
Under consideration.
62395-1 © IEC:2013 – 5 –
– A supplementary test has been added for the verification of sheath temperature using
trace heating mounted on a plate fixture.
The text of this standard is based on the following documents:
FDIS Report on voting
27/926/FDIS 27/935/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.
A list of all parts in the IEC 62395 series, published under the general title Electrical
resistance trace heating systems for industrial and commercial applications, can be found on
the IEC website.
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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – 62395-1 © IEC:2013
INTRODUCTION
IEC 62395-1 provides the essential requirements and testing appropriate to electrical
resistance trace heating equipment used in industrial and commercial applications. While
some of this work already exists in national or international standards, this standard has
collated much of this existing work and added considerably to it.
IEC 62395-2 provides detailed recommendations for the system design, installation and
maintenance of electric trace heating systems in industrial and commercial applications.
It is the objective of IEC 62395 that, when in normal use, electrical trace heating systems
operate safely under their defined conditions of use, by
a) employing heaters of the appropriate construction and meeting the test criteria detailed in
IEC 62395-1. The construction includes a metallic sheath, braid, screen or equivalent
electrically conductive covering;
b) operating at safe temperatures when designed, installed, and maintained in accordance
with IEC 62395-2.
c) having at least the minimum levels of overcurrent and earth-fault protection required in
IEC 62395-1 and IEC 62395-2.
62395-1 © IEC:2013 – 7 –
ELECTRICAL RESISTANCE TRACE HEATING SYSTEMS
FOR INDUSTRIAL AND COMMERCIAL APPLICATIONS –

Part 1: General and testing requirements

1 Scope
This part of IEC 62395 specifies requirements for electrical resistance trace heating systems
and includes general test requirements.
This standard pertains to trace heating systems that may comprise either factory-fabricated or
field-assembled (work-site) units, and which may be series and parallel trace heaters or
surface heaters (heater pads and heater panels) that have been assembled and/or terminated
in accordance with the manufacturer’s instructions.
This standard also includes requirements for termination assemblies and control methods
used with trace heating systems.
This standard provides the essential requirements and testing appropriate to electrical
resistance trace heating equipment used in industrial and commercial applications. The
products certified according to this standard are intended to be installed by persons who are
suitably trained in the techniques required and that only trained personnel carry out especially
critical work, such as the installation of connections and terminations. Installations are
intended to be carried out under the supervision of a qualified person who has undergone
supplementary training in electric trace heating systems.
This standard does not include or provide for any applications in potentially explosive
atmospheres.
This standard does not cover induction, impedance or skin effect heating.
Trace heating systems can be grouped into different types of applications and the different
conditions found during and after installation necessitate different requirements for testing.
Trace heating systems are usually certified for a specific type of installation or application.
Typical applications for the different types of installation include, but are not limited to:
a) installations of trace heating for surface heating on pipes, vessels and associated
equipment – applications include:
– freeze protection and temperature maintenance;
– hot water lines;
– oil and chemical lines;
– sprinkler system mains and supply piping;
b) outdoor exposed area installations of trace heating – applications include:
– roof de-icing;
– gutter and down-spout de-icing;
– catch basins and drains;
– rail heating ;
—————————
Further evaluation may be required to address application specific conditions such as fluctuations in impressed
voltage and voltage spikes.
– 8 – 62395-1 © IEC:2013
c) installation with embedded trace heating – applications include:
– snow melting;
– frost heave protection;
– floor warming;
– energy storage systems;
– door frames;
d) installations of trace heating internal to conduit and piping – applications include:
– snow melting – in conduit;
– frost heave protection – in conduit;
– floor warming – in conduit;
– energy storage systems – in conduit;
– internal trace heating for freeze protection of potable water lines;
– enclosed drains and culverts.
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.
IEC 60068-2-5, Environmental testing – Part 2-5: Tests – Test Sa: Simulated solar radiation at
ground level and guidance for solar radiation testing
IEC 60519-1, Safety in electroheating installations – Part 1: General requirements
IEC 60519-10, Safety in electroheating installations – Part 10: Particular requirements for
electrical resistance trace heating systems for industrial and commercial applications
IEC 62395-2:2013, Electrical resistance trace heating systems for industrial and commercial
applications – Part 2: Application guide for system design, installation and maintenance
ASTM D 5025-05, Standard Specification for Laboratory Burner Used for Small-Scale Burning
Tests on Plastic Materials
ASTM D 5207-09, Standard Practice for Confirmation of 20-mm (50-W) and 125-mm (500-W)
Test Flames for Small-Scale Burning Tests on Plastic Materials
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60519-10 and the
following apply.
NOTE 1 General definitions are given in the International Electrotechnical Vocabulary, IEC 60050. Terms relating
to industrial electroheat are defined in IEC 60050-841.
NOTE 2 The terms defined in this clause are used both in IEC 62395-1 and IEC 62395-2.
3.1
ambient temperature
temperature surrounding the object under consideration

62395-1 © IEC:2013 – 9 –
Note 1 to entry: Where trace heaters or surface heaters are enclosed in thermal insulation, the ambient
temperature is the temperature exterior to such thermal insulation.
3.1.1
maximum ambient temperature
the highest specified ambient temperature
3.1.2
minimum ambient temperature
the lowest specified ambient temperature
Note 1 to entry: Heat-loss calculations in IEC 62395-2 are based on the minimum ambient temperature.
3.2
branch circuit
portion of the wiring installation between the overcurrent device protecting the circuit and the
trace heater(s) or surface heater(s)
3.3
cold lead
electrically insulated conductor or conductors used to connect a trace heater or surface
heater to the branch circuit and designed so that it does not produce significant heat
3.4
connection
termination or splice used to attach trace heaters or surface heaters to power wiring or to
connect sections of these devices
3.5
dead leg
segment of process piping segregated from the normal flow pattern for the purpose of
providing a heat loss reference
3.6
design loading
minimum power that will meet the design requirements, in the worst conditions, after voltage
and resistance tolerances and appropriate safety factors have been considered
3.7
electrically conductive covering
metallic sheath, metallic braid, or electrically conductive material
3.8
end termination
termination, which may be heat producing, applied to a trace heater at the end opposite to
that where the power is supplied
[SOURCE: IEC 60050-426:2008, 426-20-04]
3.9
factory-fabricated unit
trace heater unit or set or surface heater unit or set, including the necessary terminations and
connections, assembled by the manufacturer
3.10
field-assembled unit
trace heaters or surface heaters supplied unterminated with terminating components to be
assembled at the work site
– 10 – 62395-1 © IEC:2013
3.11
heat loss
energy flow from a pipe, vessel or equipment to its surroundings
3.12
heat sink
part that conducts and dissipates heat away from a workpiece
Note 1 to entry: Typical heat sinks are pipe shoes, pipe supports and items of large mass such as valve actuators
or pump bodies.
3.13
heat transfer aids
thermally conductive materials, such as metallic foils or heat transfer compounds used to
increase the heat-transfer efficiency from trace heaters or surface heaters to the workpiece
3.14
heater pad
surface heater, comprising series or parallel connected elements having sufficient flexibility to
conform to the shape of the surface to be heated
3.15
heater panel
non-flexible surface heater, comprising series or parallel connected elements fabricated to
conform to the general shape of the surface to be heated
3.16
high limit temperature
maximum allowable temperature of the system, including piping, fluid and trace heating
system
3.17
integral component
component such as a heat shrink termination, a cold lead connection, a moulded end seal or
a splice, which conforms to the general shape of the trace heater or surface heater and is
exposed to the same environment as the trace heater or surface heater, which may be
factory-fabricated or field-assembled, and which is not intended to be re-used in the event of
a repair or modification
3.18
low risk of mechanical damage
installations and applications where only lower levels of impact and deformation are expected
to occur
3.19
maximum sheath temperature
maximum temperature of the outermost continuous covering of the trace heater or surface
heater
3.20
maximum withstand temperature
maximum operating or exposure temperature that does not adversely affect the thermal
stability of the trace heater or surface heater and its component parts
3.21
operating voltage
actual voltage applied to the trace heater or surface heater when in service

62395-1 © IEC:2013 – 11 –
3.22
overjacket
continuous layer of material applied outside the electrically conductive covering to protect
against corrosion
3.23
parallel trace heater
heating elements electrically connected in parallel, with the heating element either continuous
or in discrete units or zones, such that the watt density per unit length is not significantly
changed with any change in circuit length
3.24
power density
power output in watts per linear metre for trace heaters, and in watts per square metre for
surface heaters
3.25
power termination
termination applied to the end of a trace heater or surface heater at which the power is
supplied
3.26
rated output
total power or power per unit length or unit surface area of the trace heater or surface heater,
at rated voltage and temperature, which is normally expressed in watts, watts per metre or
watts per square metre
3.27
rated voltage
voltage assigned by the manufacturer to which operating and performance characteristics of
trace heaters or surface heaters are referred
3.28
routine test
test to which each individual device is subjected during or after manufacture to ascertain
whether it complies with certain criteria
3.29
series trace heater
heating elements electrically connected in series with a single current path and with a specific
resistance at a given temperature for a given length
3.30
sheath
uniform and continuous covering(s), metallic or non-metallic, enclosing the insulated
conductor(s), used to protect the trace heater or surface heater against mechanical damage
and influences from the surroundings (corrosion, moisture, etc.), which may provide an
electrical path to enable an electrical protection device to operate as intended
Note 1 to entry: See overjacket (3.22).
3.31
stabilized design
concept where the temperature of the trace heater or surface heater will, by design and use,
stabilize below the limiting temperature, under the most unfavourable conditions, without the
need for a protective system to limit the temperature

– 12 – 62395-1 © IEC:2013
3.32
start-up current
current of a trace heater or surface heater immediately upon energizing
3.33
surface heater
heater pad or panel intended to provide heat over a relatively large area, typically constructed
of one or more metallic conductors that may also include one or more discrete or continuous
electric heating elements, suitably insulated and protected
3.34
surface heater unit
surface heater suitably terminated in conformity with the manufacturer’s instructions
3.35
system documentation
information typically provided by the supplier to allow satisfactory understanding, installation
and safe use of the trace heating system
3.36
tee
electrical connection of trace heaters or surface heaters, in series or in parallel, to
accommodate a branch in the circuit and resembling the shape of a capital T
3.37
temperature controller
device or combination of devices incorporating a means of sensing temperature and of
controlling the power supplied to the trace heater or surface heater
3.38
temperature sensor
device designed to respond to temperature providing an electrical signal or mechanical
operation
3.39
thermal insulation
material having air- or gas-filled pockets, void spaces, or heat-reflecting surfaces that, when
properly applied, retard the transfer of heat
3.40
trace heater
device of linear geometry designed for the purpose of producing heat on the principle of
electrical resistance
3.41
trace heater unit
trace heater suitably terminated in conformity with the manufacturer’s instructions
3.42
trace heating
utilization of trace heaters and surface heaters as well as support components, designed for
the purpose of producing heat through heating elements electrically connected in series or in
parallel, used to maintain or raise temperatures of piping, tanks and other surfaces
3.43
type test
conformity test made on one or more items representative of the production

62395-1 © IEC:2013 – 13 –
[SOURCE: IEC 60050-151:2001, 151-16-16]
3.44
weather barrier
material that, when installed on the outer surface of thermal insulation, protects the thermal
insulation from water or other liquids, from physical damage caused by sleet, wind or
mechanical abuse, and from deterioration caused by solar radiation or atmospheric
contamination
3.45
workpiece
object to which a trace heater is applied
4 General requirements
4.1 General
Electrical resistance trace heating systems within the scope of this standard shall be designed
and constructed so as to ensure electrical, thermal and mechanical durability and reliable
performance such that, in normal use, they pose no danger to the user or the surroundings.
Trace heaters which are identified for use only in areas with a low risk of mechanical damage
are subjected to a reduced load in the impact tests in 5.2.4 and 5.2.5 and a reduced force in
the deformation test in 5.2.6, and shall be clearly marked as specified in Clause 7.
Trace heaters and surface heaters may be supplied with additional mechanical protection to
meet the requirements of this standard if they are supplied as an integral assembly
(prefabricated), and shall be marked as required by Clause 7, item g).
Trace heating equipment intended for use in contact with potable water shall be constructed
of materials that meet relevant toxicity requirements.
The manufacturer shall declare the maximum withstand temperature in degrees Celsius. The
materials used in the trace heater or surface heater shall withstand a temperature 20 K
greater than its maximum withstand temperature, when tested in accordance with 5.2.11.
4.2 Electrically conductive covering
Trace heaters and surface heaters shall be provided with an evenly distributed electrically
conductive covering which shall cover at least 70 % of the surface. Surface heating units shall
be constructed such that the electrically conductive covering shall be opposite the surface to
be heated.
4.3 Electrical circuit protection requirements for branch circuits
The minimum requirements for trace heating systems are:
a) a means of isolating all line conductors from the supply;
b) over-current protection provided for each branch circuit;
c) Earth-fault protection for each branch circuit.
The trace heater or surface heater branch circuit electrical protection shall be capable of
interrupting earth faults, as well as short-circuit faults. An earth-fault protective device or a
controller with earth-fault interruption capability shall be used. A nominal 30 mA trip rating is
recommended except where capacitive leakage may lead to nuisance tripping, in which case
devices having a trip current not greater than 300 mA may be used. These devices are
intended for use in conjunction with circuit overcurrent protection. Where conditions of
maintenance and supervision ensure that only qualified persons will service the installed

– 14 – 62395-1 © IEC:2013
systems and continued circuit operation is necessary for the safe operation of the equipment
or processes, earth-fault detection without interruption is acceptable if alarmed in a manner
assuring an acknowledged response.
4.4 Temperature requirements
4.4.1 General
A trace heating system shall be designed so that under all conditions that may reasonably be
foreseen, the surface temperature of the trace heater or surface heater does not exceed its
maximum withstand temperature or any maximum system temperature ratings. This shall be
achieved by a stabilized design or controlled design.
4.4.2 Stabilized design
Stabilized design applications, in which the maximum surface temperature of the trace heater
or surface heater is determined without thermostatic control, shall employ either the systems
approach specified in 5.2.13.2 or the product approach specified in 5.2.13.3.
4.4.3 Controlled design
The surface temperature obtained through controlled design is based on energy limitation by
temperature controllers or limiting devices.
5 Testing
5.1 Type tests – General
All trace heaters and surface heaters shall meet the requirements of the type tests given in
5.2. Trace heaters and surface heaters intended for applications described in Clause 1, items
b), c) and d) shall also meet the requirements of 5.3, 5.4 and 5.5, respectively.
Samples of trace heaters selected for testing shall be at least 3 m in length, unless otherwise
specified.
Integral components shall be subjected to the same type test as the trace heater or surface
heater unless otherwise noted. System components, other than those identified as integral,
shall be evaluated in accordance with standards relevant to their construction and use.
Tests shall be conducted at a room temperature between 10 ºC and 40 ºC unless otherwise
specified.
Separate samples shall be used for each test unless otherwise specified. These shall be
prepared in accordance with the manufacturer's recommendations.
5.2 Type tests – All applications
5.2.1 Dielectric test
The dielectric test shall be performed on trace heaters or surface heaters in accordance with
Table 1.
62395-1 © IEC:2013 – 15 –
Table 1 – Test voltages for the dielectric test
Rated voltage Test voltage
U V a.c. (r.m.s.)
< 30 V a.c. (r.m.s.)
< 60 V d.c.
≥ 30 V a.c. (r.m.s.) 2U + 1 000
√2U + 1 000
≥ 60 V d.c.
For single conductor series trace heaters or surface heaters the voltage shall be applied
between the conductor and the metallic sheath, braid, screen or equivalent electrically
conductive covering.
For multi-conductor series trace heaters or surface heaters the voltage shall be applied
between the conductors connected together and the metallic sheath, braid, screen or
equivalent electrically conductive covering, and also between each conductor in turn with the
remaining conductor(s) connected together.
For parallel trace heaters or surface heaters the voltage shall be applied between the
conductors connected together and the metallic sheath, braid, screen or equivalent
electrically conductive covering.
Alternatively the dielectric test may be conducted by submerging the trace heaters or surface
heaters in tap water at room temperature (resistivity typically 50 000 Ω·cm). The test voltage
shall be applied between the heating conductors and the water.
The rate of rise shall be neither less than 100 V/s nor more than 200 V/s and maintained for
1 min at the specified test voltage without dielectric breakdown. The test voltage waveform
shall be essentially sinusoidal, with a frequency of 45 Hz to 65 Hz.
For type tests 5.2.4, 5.2.5, 5.2.6, 5.2.7, 5.2.8, 5.2.9, 5.2.11, 5.3.3, 5.3.8, 5.3.9, 5.5.3.2, 5.5.4
and 5.7.1, for MI trace heaters, the required test voltage in 5.2.1 is reduced to 2U + 500 V a.c.
for MI trace heaters rated at or over 30 V a.c. and to √2U + 500 V d.c. for MI trace heaters
rated at or over 60 V d.c.
When determining U, the correct use of phase-to-phase or phase-to-ne
...