NORME
INTERNATIONALECEI
IEC
INTERNATIONAL
STANDARD61347-2-2
Première édition
First edition
2000-10
Appareillages de lampes –
Partie 2-2:
Prescriptions particulières pourles convertisseurs abaisseurs électroniques
alimentés en courant continu ou alternatif
pour lampes à incandescence
Lamp controlgear –
Part 2-2:
Particular requirements for d.c.
or a.c. supplied electronic step-down
convertors for filament lamps
Num éro de r éférence
Reference number
CEI/IEC 61347-2-2:200061347-2-2  IEC:2000 – 3 –
CONTENTS
Page
FOREWORD ....................................................................................................................... ... 5
INTRODUCTION ................................................................................................................... .9
Clause
1 Scope ......................................................................................................................... ... 11
2 Normative references ..................................................................................................... 113 Definitions................................................................................................................... ... 13
4 General requirements..................................................................................................... 155 General notes on tests ................................................................................................... 176 Classification ................................................................................................................ .1 7
7 Marking....................................................................................................................... ... 17
8 Protection against accidental contact with live parts........................................................ 199 Terminals..................................................................................................................... .. 21
10 Provisions for earthing.................................................................................................... 2111 Moisture resistance and insulation.................................................................................. 2112 Electric strength ............................................................................................................ .2 1
13 Thermal endurance test for windings .............................................................................. 2114 Fault conditions............................................................................................................. .2 1
15 Transformer heating....................................................................................................... 2116 Abnormal conditions....................................................................................................... 2317 Construction................................................................................................................. .. 25
18 Creepage distances and clearances ............................................................................... 2519 Screws, current-carrying parts and connections .............................................................. 2520 Resistance to heat, fire and tracking............................................................................... 2521 Resistance to corrosion.................................................................................................. 25
Annexes ........................................................................................................................ ....... 27
Table I.1 – Values of temperature rises in normal use ........................................................... 43
Table I.2 – Test temperature and testing time (in days) per cycle .......................................... 47Table I.3 – Maximum values of temperature rises under short circuit or overload conditions .. 51Table I.4 – Rated current of the protection fuse-link .............................................................. 53Table I.5 – Values of insulation resistances........................................................................... 57Table I.6 – Test voltages ...................................................................................................... 59
Table I.7 – Creepage distances (cr) and clearances (cl) and distances through
insulation (dti)............................................................................................................... ........ 6361347-2-2  IEC:2000 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
LAMP CONTROLGEAR –
Part 2-2: Particular requirements for d.c. or a.c. supplied
electronic step-down convertors for filament lamps
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the International Organizationfor Standardization (ISO) in accordance with conditions determined by agreement between the twoorganizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.
4)  In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.
5)  The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6)  Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61347-2-2 has been prepared by subcommittee 34C: Auxiliaries for
lamps, of IEC technical committee 34: Lamps and related equipment.
This first edition of IEC 61347-2-2, together with IEC 61347-1, cancels and replaces the
second edition of IEC 61046, published in 1993, and constitutes a minor revision.
This standard shall be used in conjunction with IEC 61347-1. It was established on the basis of
the first edition (2000) of that edition.
This part 2 supplements or modifies the corresponding clauses in IEC 61347-1, so as to
convert that publication into the IEC Standard: Particular requirements for d.c. or a.c. suppliedelectronic step-down convertors for filament lamps.
NOTE  In this standard, the following print types are used:
–Requirements proper: in roman type.
–Test specifications: in italic type .
– Explanatory matter: in smaller roman type .61347-2-2  IEC:2000 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
34C/499/FDIS 34C/513/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.
Annexes A, B, C, D, E, F, H and I form an integral part of this standard.Annex G is for information only.IEC 61347 consists of the following parts, under the general title 
Lamp controlgear:
–Part 1: General and safety requirements
–Part 2-1: Particular requirements for starting devices (other than glow starters)
–Part 2-2: Particular requirements for d.c. or a.c. supplied electronic step-down convertors
for filament lamps
–Part 2-3: Particular requirements for a.c. supplied electronic ballasts for fluorescent lamps
–Part 2-4: Particular requirements for d.c. electronic ballasts for general lighting
–Part 2-5: Particular requirements for d.c. supplied electronic ballasts for public transport
lighting
–Part 2-6: Particular requirements for d.c. supplied electronic ballasts for aircraft lighting
–Part 2-7: Particular requirements for d.c. supplied electronic ballasts for emergency lighting
–Part 2-8: Particular requirements for ballasts for fluorescent lamps
–Part 2-9: Particular requirements for ballasts for discharge lamps (excluding fluorescent
lamps)
–Part 2-10: Particular requirements for electronic invertors and convertors for high-frequency
operation of cold start tubular discharge lamps (neon tubes)
–Part 2-11: Particular requirements for miscellaneous electronic circuits used with
luminaires 1)
The committee has decided that the contents of this publication will remain unchanged until2003. At this date, the publication will be
•reconfirmed;
•withdrawn;
•replaced by a revised edition, or
•amended.
___________
1)  To be published.61347-2-2  IEC:2000 – 9 –
INTRODUCTION
This first edition of IEC 61347-2-2, published in conjunction with IEC 61347-1, represents an
editorial review of IEC 61046. The formatting into separately published parts provides for easeof future amendments and revisions. Additional requirements will be added as and when aneed for them is recognized.
This standard, and the parts which make up IEC 61347-2, in referring to any of the clauses of
IEC 61347-1, specify the extent to which such a clause is applicable and the order in which thetests are to be performed; they also include additional requirements, as necessary. All partswhich make up IEC 61347-2 are self-contained and, therefore, do not include references toeach other.
Where the requirements of any of the clauses of IEC 61347-1 are referred to in this standard
by the phrase "The requirements of clause n of IEC 61347-1 apply", this phrase is interpretedas meaning that all requirements of the clause in question of part 1 apply, except any which areclearly inapplicable to the specific type of lamp controlgear covered by this particular part ofIEC 61347-2.61347-2-2  IEC:2000 – 11 –
LAMP CONTROLGEAR –
Part 2-2: Particular requirements for d.c. or a.c. supplied
electronic step-down convertors for filament lamps
1 Scope
This part of IEC 61347 specifies particular safety requirements for electronic step-down
convertors for use on d.c. supplies up to 250 V or a.c. supplies up to 1 000 V at 50 Hz or 60 Hz
and rated output voltage ≤50 V r.m.s. at a frequency deviating from the supply frequency or
≤502  V unsmoothed d.c. between conductors or between any conductor and earth,
associated with tungsten-halogen lamps as specified in IEC 60357 and other filament lamps.
NOTE  The limit of 50 V rated output voltage is in accordance with band I of IEC 60449.
Particular requirements for electronic step-down convertors with means of protection against
overheating are given in annex C.
Particular requirements for stationary independent SELV convertors, which are part of the
wiring in installations, are given in annex I.
Performance requirements are covered by IEC 61047.Plug-in convertors, being part of the luminaire, are covered as for built-in convertors by the
additional requirements of the luminaire standard.
2 Normative references
For the purpose of this part of IEC 61347, the normative references given in clause 2 ofIEC 61347-1 which are mentioned in this standard apply, together with the following normativereferences.
IEC 60051 (all parts), 
Direct acting indicating analogue electrical measuring instruments and
their accessories
IEC 60065, Safety requirements for mains operated electronic and related apparatus for
household and similar general use
IEC 60083, Plugs and socket-outlets for domestic and similar general use standardized in
member countries of IEC
IEC 60085, Thermal evaluation and classification of electrical insulation
IEC 60127 (all parts), Miniature fuses
IEC 60269-2, Low-voltage fuses – Part 2: Supplementary requirements for fuses for use by
authorized persons (fuses mainly for industrial application)61347-2-2  IEC:2000 – 13 –
IEC 60269-2-1, Low-voltage fuses – Part 2-1: Supplementary requirements for fuses for use by
authorized persons (fuses mainly for industrial application) – Sections I to V: Examples of types
of standardized fuses
IEC 60269-3:1987, Low-voltage fuses – Part 3: Supplementary requirements for fuses for use
by unskilled persons (fuses mainly for household and similar applications)
IEC 60269-3-1, Low-voltage fuses – Part 3-1: Supplementary requirements for fuses for use by
unskilled persons (fuses mainly for household and similar applications) – Sections I to IV
IEC 60357, Tungsten-halogen lamps (non-vehicle)
IEC 60364-4-41, Electrical installations of buildings – Part 4: Protection for safety – Chapter 41:
Protection against electric shock
IEC 60449, Voltage bands for electrical installations of buildings
IEC 60454 (all parts), Specifications for pressure-sensitive adhesive tapes for electrical
purposes
IEC 60598-2-6, Luminaires – Part 2: Particular requirements – Section 6: Luminaires with
built-in transformers for filament lamps
IEC 60742:1983, Isolating transformers and safety isolating transformers – Requirements
Amendment 1 (1992)
IEC 60906 (all parts), IEC system of plugs and socket-outlets for household and similar
purposes
IEC 60906-1, IEC system of plugs and socket-outlets for household and similar purposes –
Part 1: Plugs and socket-outlets 16 A 250 V a.c.
IEC 61047, DC or a.c. supplied electronic step-down convertors for filament lamps –
Performance requirements
IEC 61347-1,  Lamp controlgear – Part 1: General and safety requirements
3 Definitions
For the purpose of this part of IEC 61347, the definitions given in clause 3 of IEC 61347-1
apply, together with the following:
3.1
electronic step-down convertor (convertor)
unit inserted between the supply and one or more tungsten-halogen or other filament lamps
which serves to supply the lamp(s) with its (their) rated voltage, generally at high frequency.The unit may consist of one or more separate components and may include means fordimming, correcting the power factor and suppressing radio interference61347-2-2  IEC:2000 – 15 –
3.2
d.c. or a.c. supplied convertor
convertor that includes stabilizing elements for operating one or more filament lamps, generally
at high frequency
3.3
safety extra-low voltage (SELV)-equivalent convertor
built-in or associated convertor for operating one or more filament lamps with an output voltage
equivalent to a SELV
NOTE  For the purposes of this standard, SELV-equivalent convertors, complying with 8.1 and 8.2 are deemed as
giving protection against electric shock equivalent to SELV.
3.4
independent SELV convertor
convertor providing a SELV output isolated from the supply mains by means such as a safety
isolating transformer, as specified in IEC 60742
3.5
associated convertor
convertor designed to supply specific appliances or equipment, incorporated or not incor-
porated, but specially designed to be used only with the specific appliance(s) or equipment
3.6
stationary convertor
either a fixed convertor or one which cannot be easily moved from one place to another
3.7
plug-in convertor
convertor incorporated in an enclosure provided with an integral plug as the means of
connection of the electrical supply
3.8
rated output voltage
output voltage, at rated supply voltage, rated frequency and at unity power factor, assigned to
the convertor
3.9
half-resistance effect
effect which can occur at the end of lamp life due to filament deformation or crystallization
effects resulting in a partial short-circuit of the lamp filament, which can cause overloading ofthe convertor
3.10
arcing
effect which can occur in lamps at a voltage of ≥20 V and which can cause overloading of the
convertor
4 General requirements
The requirements of clause 4 of IEC 61347-1 apply, together with the following additionalrequirement:
Independent SELV convertors shall comply with the requirements of annex I. This includes
insulation resistance, electric strength, creepage distances and clearances of the outer case.61347-2-2  IEC:2000 – 17 –
5 General notes on tests
The requirements of clause 5 of IEC 61347-1 apply, with the following additional requirement:
Number of specimens
The following number of specimens shall be submitted for testing:
–one unit for the tests of clauses 6 to 12 and 15 to 21;
–one unit for the tests of clause 14 (additional units or components, where necessary, may
be required in consultation with the manufacturer).
6 Classification
Convertors are classified according to the method of installation given in clause 6 ofIEC 61347-1 and according to:
Protection against electric shock
– SELV-equivalent or isolating convertors (this type of convertor can be used instead of
double-wound transformers with reinforced insulation; see IEC 60598-2-6);
–auto-wound convertors;
–independent SELV convertors.
7 Marking
7.1 Mandatory marking
Convertors, other than integral convertors, shall be clearly and durably marked, in accordance
with the requirements of 7.2 of IEC 61347-1, with the following mandatory markings:
–items a), b), c), d), e), f), k), l), m) of 7.1 of IEC 61347-1 together with
–rated output voltage.
7.2 Information to be provided if applicable
In addition to the above mandatory markings, the following information, if applicable, shall be
given either on the convertor, or be made available in the manufacturer ’s catalogue or similar:
–items h), i), and j) of 7.1 of IEC 61347-1 together with
–mention whether the convertor has mains-connected windings,
–mention that they are SELV-equivalent convertors, if applicable.61347-2-2  IEC:2000 – 19 –
8 Protection against accidental contact with live parts
The requirements of clause 10 of IEC 61347-1 apply, together with the following additional
requirements:
8.1 
For SELV-equivalent convertors, the accessible parts shall be insulated from live parts by
double or reinforced insulation.
Subclauses 9.3.4 and 9.3.5 of IEC 60065 shall apply.
8.2 
Output circuits of SELV-equivalent convertors may have exposed terminals if
–the rated output voltage under load does not exceed 25 V r.m.s.;
–the no-load output voltage does not exceed 33 V r.m.s. or 33 2  V peak or 33 2 V
unsmoothed d.c.
Compliance is checked by measuring the output voltage when steady conditions are
established, the convertor being connected to rated supply voltage and rated frequency. For
the test under load, the convertor is loaded with a resistance which would give rated output at
rated output voltage.
For convertors with more than one rated supply voltage, the requirement is applicable for each
of the rated supply voltages.
NOTE  The limit of 25 V r.m.s. is based on IEC 60364-4-41.
Convertors with a rated output voltage above 25 V shall have insulated terminals.
In the case of capacitors which are connected between SELV-equivalent output and primary
circuits, two capacitors in series with the same value according to 9.3.4 of IEC 60065 shall beused.
Each capacitor shall comply with the requirements of 14.2 of IEC 60065.
In the case of resistors which are connected to SELV-equivalent output and primary circuits,
two resistors in series with the same value shall be used.
If other components are necessary for bridging the separating transformer, for example
resistors, clause 14 of IEC 60065 shall apply.
8.3 
Convertors incorporating capacitors of a total capacitance exceeding 0,5 µF shall be
constructed so that the voltage at the convertor terminations does not exceed 50 V, 1 min afterdisconnection of the convertor from a source of supply at rated voltage.61347-2-2  IEC:2000 – 21 –
9 Terminals
The requirements of clause 8 of IEC 61347-1 apply.
10 Provisions for earthing
The requirements of clause 9 of IEC 61347-1 apply.
11 Moisture resistance and insulation
The requirements of clause 11 of IEC 61347-1 apply, together with the following additional
requirements:
For SELV-equivalent convertors, the insulation between input and output terminals not bonded
together shall be adequate.
With double or reinforced insulation, the resistance shall be not less than 4 M Ω.
12 Electric strength
The requirements of clause 12 of IEC 61347-1 apply, together with the following additional
requirement.
Insulation conditions of windings of separating transformers in SELV-equivalent convertors
shall apply according to 14.3.2 of IEC 60065.
13 Thermal endurance test for windings
The requirements of clause 13 of IEC 61347-1 are not applicable.
14 Fault conditions
The requirements of clause 14 of IEC 61347-1 apply, together with the following additionalrequirements:
In the case of convertors provided with the marking 
, the requirements specified in annex C
shall be fulfilled.
In addition, the output voltage of the convertor, when operated under fault conditions, shall not
exceed 115 % of the rated output voltage.
15 Transformer heating
In SELV-equivalent convertors, windings of separating transformers shall be tested accordingto 7.1 of IEC 60065.
15.1 Normal operation
For normal operation the values in column I of table 3 of IEC 60065 shall apply.61347-2-2  IEC:2000 – 23 –
15.2 Abnormal operation
For operation under abnormal conditions according to clause 16 and fault conditions according
to clause 14 of this standard, the values in column II of table 3 of IEC 60065 shall apply.
The values of the temperature rise in table 3 of IEC 60065, columns I and II, are based on a
maximum ambient temperature of 35 °C. Because the test will be made with the case
temperature at tc, the relevant ambient temperature shall be measured and the values in
table 3 changed respectively. If these temperature rises are higher than those allowed by the
class of the relevant insulating material, the nature of the material is the governing factor. Thepermissible temperature rises are based on the recommendations in IEC 60085. The materialsquoted in table 3 of IEC 60065 are shown only as examples. If materials other than those listedin IEC 60085 are used, the maximum temperatures shall not exceed those which have provedto be satisfactory.
Tests shall be made under conditions such that the convertor is brought to 
tc as reached under
normal operation.
NOTE  The test can be carried out in such a way that the convertor is operated at thermal equilibrium under normal
conditions in the test enclosure described in annex F, in an ambient temperature such that a case temperature of
tc0
5+
− °C is obtained.
For moulded-in transformers specially prepared samples provided with thermocouples shall be
submitted for testing.
16 Abnormal conditions
The convertor shall not impair safety when operated under abnormal conditions.
In addition, the output voltage of the convertor when operated under fault conditions shall not
exceed 115 % of the rated output voltage.
Compliance is checked by the following test at any voltage between 90 % and 110 % of the
rated supply voltage.
Each of the following conditions shall be applied with the convertor operating according to the
manufacturer's instructions (including heatsinks, if specified) for 1 h.
a) No lamp is inserted.
b) Double the number of lamps of the type for which the convertor is designed are connected
in parallel to the output terminals.
c) The output terminals of the convertor shall be short-circuited. If the convertor is designed
for operation of more than one lamp, each pair of output terminals for connecting a lamp
shall be short-circuited in turn.
During and at the end of the tests specified under a) to c), the convertor shall show no defect
impairing safety, nor shall any smoke or flammable gases be produced.61347-2-2  IEC:2000 – 25 –
17 Construction
The requirements of clause 15 of IEC 61347-1 apply, together with the following additional
requirement.
Socket-outlets in the output circuit shall not accept plugs complying with IEC 60083 and
IEC 60906; neither shall it be possible to engage plugs accepted by socket-outlets in the outputcircuit with socket-outlets complying with IEC 60083 and IEC 60906.
Compliance is checked by inspection and by manual test.
18 Creepage distances and clearances
Unless otherwise specified in clause 14, the requirements of clause 16 of IEC 61347-1 apply.
19 Screws, current-carrying parts and connections
The requirements of clause 17 of IEC 61347-1 apply.
20 Resistance to heat, fire and tracking
The requirements of clause 18 of IEC 61347-1 apply.
21 Resistance to corrosion
The requirements of clause 19 of IEC 61347-1 apply .61347-2-2  IEC:2000 – 27 –
Annex A
(normative)
Test to establish whether a conductive part
is a live part which may cause an electric shock
The requirements of annex A of IEC 61347-1 apply.
Annex B
(normative)
Particular requirements for thermally protected
lamp controlgear
The requirements of annex B of IEC 61347-1 are not applicable.
Annex C
(normative)
Particular requirements for electronic lamp controlgear
with means of protection against overheating
The requirements of annex C of IEC 61347-1 apply.
Annex D
(normative)
Requirements for carrying out the heating
tests of thermally protected lamp controlgear
The requirements of annex D of IEC 61347-1 apply.
Annex E
(normative)
Use of constant S other than 4 500 in tw tests
The requirements of annex E of IEC 61347-1 apply only for windings of 50/60 Hz.61347-2-2  IEC:2000 – 29 –
Annex F
(normative)
Draught-proof enclosure
The requirements of annex F of IEC 61347-1 apply.
Annex G
(informative)
Explanation of the derivation of the values of pulse voltages
The requirements of annex G of IEC 61347-1 are not applicable.
Annex H
(normative)
Tests
The requirements of annex H of IEC 61347-1 apply.61347-2-2  IEC:2000 – 31 –
Annex I
(normative)
Particular additional requirements for independent
 SELV d.c. or a.c. supplied electronic step-down
convertors for filament lamps
NOTE  The text of this annex is partially taken from IEC 60742 and its amendment 1.
I.1  Scope
This annex applies to independent convertors for use as the SELV supply for class III
luminaires of 25 A maximum. It consists of the relevant requirements of IEC 60742 accordingto 4.12 of that standard for associated transformers.
I.2  Definitions
I.2.1
short-circuit proof convertor
convertor in which the temperature rise does not exceed the specified limits when the convertor
is overloaded or short-circuited and which remains capable of functioning after the overload isremoved
I.2.2
non-inherently short-circuit proof convertor
short-circuit proof convertor which incorporates a protective device which opens the circuit or
reduces the current in the input circuit or the output circuit when the convertor is overloaded orshort-circuited
NOTE  Examples of protective devices are fuses, overload releases, thermal fuses, thermal links, thermal cut-outs,
PTC resistors and automatic break-off mechanical devices.
I.2.3
inherently short-circuit proof convertor
short-circuit proof convertor in which the temperature, in the case of overload or short circuit
and in the absence of a protective device, does not exceed the specified limits, and whichcontinues to function after the overload or short circuit is removed
I.2.4
fail-safe convertor
convertor which, after abnormal use, fails to function but presents no danger to the user or
surroundings
I.2.5
non-short-circuit proof convertor
convertor designed to be protected against excessive temperature by means of a protective
device which is not incorporated in the convertor
I.2.6
HF transformer
component part of the convertor operating with frequency deviating from the supply frequency61347-2-2  IEC:2000 – 33 –
I.3  Classification
Independent convertors are classified as follows:
I.3.1  According to their protection against electric shock
–class I convertors;
–class II convertors.
I.3.2  According to the short-circuit protection or protection against abnormal use
–non-inherently short-circuit proof convertors;
–inherently short-circuit proof convertors;
–fail-safe convertors;
–non-short-circuit proof convertors.
I.4  Marking
When symbols are used, they shall be as follows:
PRI  Input
SEC  Output
 Direct current
N  Neutral
 Single phase
 Fuse link (add symbol for time-current characteristic)
ta  Rated maximum ambient temperature
 Frame or core terminal
 Safety isolating convertor
 F  or F Fail-safe convertor
   or  Non-short-circuit proof convertor
   or  Short-circuit proof convertor
 (inherently or non-inherently)
The last three symbols may be arranged with symbols for isolating convertors or for safety
isolating convertors.
EXAMPLE  The dimensions of the symbol for class II construction shall be such that the length
of the sides of the outer square is about twice the length of the sides of the inner square. Thelength of the sides of the outer square shall be not less than 5 mm, unless the largestdimension of the convertor does not exceed 15 cm, in which case the dimension of the symbolmay be reduced, but the length of the sides of the outer square shall be not less than 3 mm.61347-2-2  IEC:2000 – 35 –
I.5  Protection against electric shock
I.5.1   There shall be no connection between the output circuit and the body or the protective
earthing circuit, if any, unless this is allowed under the conditions specified in 8.2.
Compliance is checked by inspection.
I.5.2   The input and output circuits shall be electrically separated from each other, and the
construction shall be such that there is no possibility of any connection between these circuits,
either directly or indirectly, through other metal parts.
The expression ‘circuits ’ also covers windings of the internal HF transformer of the convertor, if
any.
In particular, precautions shall be taken to prevent
–undue displacement of input or output windings or the turns of the HF transformer thereof;
–undue displacement of internal circuits or wires for external connections;
–undue displacement of parts of circuits, or of internal wiring, in the event of rupture of wires
or loosening of connections;
–wires, screws, washers and the like from bridging any part of the insulation between the
input and output circuits, including the connections of windings of the HF transformer,should they loosen or become free.
It is not to be expected that two independent fixings will become loose at the same time.
Compliance is checked for the convertor by inspection, taking I.5.2.1 up to and including I.5.2.5
into consideration, and, for the convertor enclosure, by the tests of 4.13 of IEC 60598-1.
I.5.2.1   The insulation between the input and output winding(s) of the HF transformer shall
consist of double or reinforced insulation, unless the requirements of I.5.2.4 are complied with.
In addition, the following requirements apply:
–for class II convertors, the insulation between the input circuits and the body, and between
the output circuits and the body shall consist of double or reinforced insulation;
–for class I convertors, the insulation between the input circuits and the body shall consist of
basic insulation, and the insulation between the output circuits and the body shall consist ofsupplementary insulation.
I.5.2.2   Where an intermediate metal part (for example, the magnetic core of the HF
transformer) not connected to the body is located between the input and output windings of the
HF transformer, the insulation between the input and output windings via the intermediatemetal part shall consist of double or reinforced insulation, and, for class II convertors, theinsulation between the input windings and the body and between the output windings and thebody via the intermediate metal part of the HF transformer shall consist of double or reinforcedinsulation.61347-2-2  IEC:2000 – 37 –
The insulation between the intermediate metal part and the input or output windings of the HF
transformer shall, in both cases, consist of at least basic insulation rated for the relevant circuitvoltage.
An intermediate part which is separated from one of the windings by double or reinforced
insulation is considered as being connected to the other winding of the HF transformer.
I.5.2.3   Where serrated tape is used as insulation, at least one additional layer shall be applied
to reduce the risk of serration of two adjacent layers.
I.5.2.4   For class I convertors for fixed connection, the insulation between the input and output
windings of the HF transformer may consist of basic insulation plus protective screening
instead of double or reinforced insulation, provided the following conditions are complied with.
For the purpose of this subclause, the expression "windings" does not include internal circuits.
a) The insulation between the input winding and the protective screen shall comply with the
requirements for basic insulation (rated for the input voltage).
b) The insulation between the protective screen and the output winding shall comply with the
requirements for basic insulation (rated for the output voltage).
c) The metal screen shall, unless otherwise specified, consist of a metal foil or of a wire-
wound screen extending at least the full width of one of the windings adjacent to thescreen; a wire-wound screen shall be wound tight without space between the turns.
d) The metal screen shall, in order to prevent eddy current losses due to creation of a shorted
turn, be so arranged that both edges cannot simultaneously touch a magnetic core.
e) The metal screen and its lead-out wire shall have a cross-section sufficient to ensure that,
if a breakdown of insulation should occur, an overload device will open the circuit beforethe screen is destroyed.
f) The lead-out wire shall be soldered to the metal screen or fixed in an equally reliable
manner.
I.5.2.5   The last turn of each winding of the HF transformer shall be retained by suitable
means, for example, by tape or a suitable bonding agent.
Where cheekless bobbins are used, the end turns of each layer shall be retained by suitable
means. Each layer can, for example, be interleaved with adequate insulation materialprojecting beyond the end turns of each layer and, moreover
either
–the winding(s) shall be impregnated with hard-baking or cold-setting material, substantially
filling the intervening spaces and effectively sealing off the end turns;
or–the winding(s) shall be held together by means of insulating material.
It is not expected that two independent fixings will become loose at the same time.
Compliance is checked for the convertor by inspection, taking I.5.2.1 up to and including I.5.2.5
into consideration and clauses 11, 12 and I.8 of this standard, and, for the convertor enclosure,
by the tests of 4.13 of IEC 60598-1.61347-2-2  IEC:2000 – 39 –
I.5.3   The input and output circuits are permitted to be bridged by components, such as
capacitors, resistors and opto-couplers.
I.5.3.1   Capacitors and resistors shall comply with 8.2 of this standard.
I.5.3.2   Opto-couplers
Under consideration.
I.6  Heating
I.6.1   Convertors and their supports shall not attain excessive temperature in normal use.
Compliance is checked by the test of I.6.2. Moreover, the following requirements apply to the
windings.
I.6.1.1   If the manufacturer has neither stated which classified material has been used, nor
stated any value of ta and the measured temperature rise does not exceed the value given in
table I.1 for class A material, the tests of I.6.3 are not made.
However, if the measured temperature rise exceeds the value given in table I.1 for class A
material, the active parts of convertors (magnetic core and windings) are submitted to the testsof I.6.3. The temperature of the heating cabinet is chosen according to table I.2. Thetemperature rise value to be chosen in table I.2 is the next higher value to the measuredtemperature rise value.
I.6.1.2   If the manufacturer has not stated which classified material has been used but has
stated a value of
 ta, and the measured temperature rise does not exceed the value given in
table I.1 for class A material, taking the value of ta into account (see I.6.2), the tests of I.6.3
are not made.
However, if the measured temperature rise, taking the value of ta into account, exceeds the
value given in table I.1 for class A material, the active parts of convertors (magnetic core and
windings) are submitted to the tests of I.6.3. The temperature of the heating cabinet is chosenaccording to table I.2, taking the value of 
ta into account. The temperature rise value to be
chosen in table I.2 is the next higher value to the calculated temperature rise value.
I.6.1.3   If the manufacturer has stated which classified material has been used, but has not
stated any value of ta and the measured temperature rise does not exceed the relevant value
given in table I.1, the tests of I.6.3 are not made.
However, if the measured temperature rise exceeds the value given in table I.1, the convertor
is deemed not to comply with the requirements of this clause.
I.6.1.4  If the manufacturer has stated which classified material has been used and has stated
a value of ta, and the measured temperature rise does not exceed the relevant value given in
table I.1, taking the value of  ta into account, the tests of I.6.3 are not made.
However, if the measured temperature rise, taking the value of  ta into account, exceeds the
value given in table I.1, the convertor is deemed not to comply with the requirements of this
clause.61347-2-2  IEC:2000 – 41 –
I.6.2   Temperature rises are determined under the following conditions when steady state is
established.
The test and the measurements are made in a draught-free location having dimensions such
that the test results are not influenced. If the ta rating of the convertor exceeds 50 °C, the room
temperature during the test shall be within 5 °C of the ta rating and shall preferably be at the ta
rating.
Portable convertors are placed on a dull, black painted plywood support, stationary convertors
are mounted as in normal use, also on a dull, black painted plywood support. The support isapproximately 20 mm thick and has dimensions which are at least 200 mm in excess of thoseof the orthogonal projection of the specimen on the support.
Convertors are connected to rated supply voltage and loaded with a resistance which would
give rated output at rated output voltage and, for a.c. current, at rated power factor.
No adjustments are made, except that the supply voltage is increased by 6 %.Associated convertors are operated under the conditions occurring when the appliances or
other equipment is operated under the conditions of normal use indicated in the specificationfor the relevant appliance or equipment. If the design of the appliance or other equipment issuch that the convertor can be operated without load, the test is repeated under no-loadconditions.
Temperature rises of windings are determined by the resistance method or by means of
thermocouples so chosen and positioned that they have the minimum effect on the temperatureof the part under test. In this case, specially prepared samples need to be submitted.
When determining the temperature rise of windings, the ambient temperature is measured at
such a distance from the specimen that it does not influence the temperature reading. At thispoint, the temperature of the air shall not vary by more than 10
 K during the test.
During the test,
–for convertors without a ta marking, the temperature rise shall not exceed the values shown
in table I.1;
–for convertors with a ta marking, the sum of the temperature rise and ta shall not exceed the
sum of the values shown in table I.1 and 25 °C.
EXAMPLE – Allowed temperature rise of windings for
a) convertor  ta = +35 °C, class A material
∆t + 35 ≤ 75 + 25
∆t ≤ 65 K
b) convertor ta = –10 °C, class E material
∆t + (–10) ≤ 90 + 25
∆t ≤ 125 K61347-2-2  IEC:2000 – 43 –
Also, the electrical connections shall not work loose, creepage distances and clearances shall
not be reduced to less than the values specified in I.11. Sealing compound shall not flow outand overload protection devices shall not operate.
Table I.1 – Values of temperature rises in normal use
Parts Temperature rise
K
Windings (with which bobbins and laminations have
contact), if the winding insulation is
–of class A material a
–of class E material
–of class B material
–of class F material
–of class H material
–of other material b75
9095
115140
a  The material classification is in accordance with IEC 60085 or IEC 60317-0-1 or equivalent standards.
b  If materials other than those specified in IEC 60085 under classes A, E, B, F and H are used, they shall
withstand the tests of I.6.3
NOTE  In the future, this classification will be replaced by  tw marking (requirements are under consideration).
The values in the table are based on an ambient temperature not normally exceeding 25 °C,
but occasionally reaching 35 °C.
The winding temperatures are based on IEC 60085, but have been adjusted to take into
account the fact that, in these tests, the temperatures are mean and not hot-spot values.
Immediately after this test, the sample shall withstand an electric strength test as specified in
I.8.3, the test voltage being applied between input and output windings only.
For class I convertors, care is taken that other insulation is not stressed by a voltage exceeding
the relevant value specified in I.8.3.
It is recommended that the measurement be made on each winding separately, and that the
resistance of windings at the end of the test be determined by taking resistance measurementsas soon as possible after switching off, and then at short intervals, so that a curve of resistanceagainst time can be plotted to ascertain the resistance at the instant of switching off.
For convertors with more than one output winding or a tapped output winding, the results to be
considered are those showing the greatest temperature rise.
For convertors having other than continuous working conditions, the test conditions may be
found in the relevant clauses.61347-2-2  IEC:2000 – 45 –
The value of the temperature rise of a winding is calculated from the formula with
x = 234,5 for copper;
x = 229 for aluminium;
() ( )1 2 1
11 2tt txRR Rt − − +−=∆
and where
∆t is the temperature rise above t2, in kelvins;
R1is the resistance at the beginning of the test, at temperature t1, in ohms;
R2is the resistance at the end of the test, when steady conditions have been established,
in ohms;
t1 is the room temperature at the beginning of the test, in degrees Celsius;
t2 is the room temperature at the end of the test, in degrees Celsius.
At the beginning of the test, the windings shall be at room temperature.
I.6.3  Tests
When applicable (see I.6.1), the active parts of the convertors (magnetic core and windings)
are subjected to the following cycling test, each cycle consisting of a heat run, a moisturetreatment and a vibration test. Measurements are made after each cycle.
The number of specimens shall be as indicated in clause 5 (three additional specimens). The
specimens shall be subjected to 10 test cycles.
I.6.3.1  Heat run
Dependent on the type of insulation, the specimens are kept in a heating cabinet for the time
and the temperature specified in table I.2.
The temperature in the heating cabinet shall be maintained to within a tolerance of ±3 °C.61347-2-2  IEC:2000 – 47 –
Table I.2 – Test temperature and testing time (in days) per cycle
Test temperature
°CTemperature rise for insulation systems*
K
75 90 95 115 140
220
210200190180170160150140130120–
––––––––47–
––––––47–––
––––47–––––
–47
14
––––––4
7
14
––––––––
Temporary classification
assigned for the tests ofclause I.7 onlyAE B F H
* Based on an ambient temperature of 25 °C, occasionally reaching 35 °C.
I.6.3.2   Moisture treatment
The specimens are submitted for two days (48 h) to a moisture treatment according to
clause 11 of IEC 61347-1.
I.6.3.3  Vibration test
With the axis of the windings vertical, the specimens are submitted for 1 h to a vibration test,
exerting a maximum acceleration of 1,5 g at rated supply frequency.
I.6.3.4  Measurements
After each cycle the insulation resistance and electric strength are measured according to
I.8.1. After the heat runs, the specimens are allowed to cool down to ambient temperaturebefore the moisture treatment is made.
The values of the test voltage for the dielectric test according to clause I.8 are, however,
reduced to 35 % of the specified values and the testing time shall be doubled, except that thewindings test according to I.8.3 shall be made with a test voltage of at least 1,2 times ratedsupply voltage. A specimen is considered not to comply with the windings test if the no-loadcurrent or the ohmic component of the no-load input deviates from the corresponding value,obtained during the first measurement, by more than 30 %. If, after completion of all 10 cycles,one or more specimens have failed, the convertor is considered as not complying with theendurance test.
In the case of one specimen failing due to breakdown between the turns of a winding, this is
not considered to be a failure of the endurance test. The test can be continued with theremaining two specimens.61347-2-2  IEC:2000 – 49 –
I.7  Short-circuit and overload protection
I.7.1   Convertors shall not become unsafe due to short circuits and overloads which may occur
in normal use.
Compliance is checked by inspection and by the following tests which are made immediately
after the test according to I.6.2 without the position of the convertor being changed at 1,06
times rated supply voltage, or, for non-inherently short-circuit proof transformers, at any value
of the supply voltage between 0,94 and 1,06 times rated supply voltage:
–for inherently short-circuit proof convertors, by the tests of I.7.2;
–for non-inherently short-circuit proof convertors, by the tests of I.7.3;
–for convertors provided with non-self-resetting thermal cut-outs which can neither be reset
nor replaced, by the tests of I.7.5 as if they were of the fail-safe type;
–for non-short-circuit proof convertors, by the tests of I.7.4;
–for fail-safe convertors, by the tests of I.7.5;
–for convertors combined with a rectifier, the tests of I.7.2 or I.7.3 are made twice, once with
the short circuit applied on one side of the rectifier and again with the short circuit applied
at the other side of the rectifier;
–for high-frequency transformers with more than one output winding or a tapped output
winding, the results to be considered are those showing the greatest temperature rise. All
windings which are intended to be loaded at the same time are loaded at rated output and
then the short circuit or overload, as specified, is made on the chosen output winding.
For the tests of I.7.2, I.7.3 and I.7.4, temperature rise shall not exceed the values given in
table I.3.61347-2-2  IEC:2000 – 51 –
Table I.3 – Maximum values of temperature rises under short circuit or overload conditions
Insulation classification A E B F H
Maximum temperature rise
K
Type of protection:
Winding protected inherently 125 140 150 165 185
Winding protected by protective device:
–  during first hour or, for fuses having a
rated current exceeding 63 A, during the firsttwo hours a175 190 200 215 235
–  after first hour, peak value b150 165 175 190 210
–  after first hour, arithmetic mean value b125 140 150 165 185
External enclosures (which may be touched with
the standard test finger) 80
Rubber insulation of wiring 60
PVC insulation of wiring 60
Supports (i.e. any area on the pine plywoodsurface covered by convertor)80
a  After the test of I.7.3.3, these values may be exceeded due to the thermal inertia of the convertor.
b  Does not apply to the test of I.7.3.3.
I.7.2   Inherently short-circuit proof convertors are tested by short-circuiting the output windings
until steady-state conditions are reached.
I.7.3   Non-inherently short-circuit proof convertors are tested as indicated in I.7.3.1 to I.7.3.5.
I.7.3.1   The output terminals are short-circuited. The incorporated overload protection device
shall operate before the temperature rise exceeds the values shown in table I.3 for any value of
the supply voltage between 0,94 and 1,06 times rated supply voltage.
I.7.3.2   If protected by a fuse in accordance with either IEC 60269-2 or IEC 60269-3, or a
technically equivalent fuse, the convertor is loaded for a time T and with a current equal to k
times the current marked on the convertor as the rated current of the protection fuse-link,
where k and T have the values shown in table I.4.61347-2-2  IEC:2000 – 53 –
Table I.4 – Rated current of the protection fuse-link
Values marked as rated current
of protection fuse-link In for gG
AT
hk
In ≤ 4
4 < In < 16
16 ≤ In ≤ 63
63 < In ≤ 160
160 < In ≤ 2001
11232,1
1,91,61,61,6
For cylindric fuses gG type B for use by unskilled persons (IEC 60269-3-1) and for fuses for use by authorized
persons with fuse-links for bolted connections (IEC 60269-2-1), the value of k is 1,6 for In < 16 A.
For D-type fuses for use by unskilled persons (IEC 60269-3-1) for a rated current of 16 A, the value of k is 1,9.
I.7.3.3   If protected by miniature fuses in accordance with IEC 60127 or by a technically
equivalent fuse, the convertor is loaded for 30 min with a current equal to 2,1 times the value of
the rated current of the fuse.
I.7.3.4   If protected by an overload protection device other than a fuse, the convertor is loaded
by a current equal to 0,95 times the value of the lowest current which causes the device to
operate, until steady-state conditions are reached.
I.7.3.5   For the tests of I.7.3.2 and I.7.3.3, the fuse-link is replaced by a link of negligible
impedance.
For the tests of I.7.3.4, the test current is obtained at ambient temperature, commencing at
1,1 times the rated tripping current, which is slowly decreased in steps of 2 % until the currentvalue is obtained for which the overload protection device does not operate.
If thermal fuses are used, the test current of one specimen shall be increased in steps of 5 %.
After each step, the convertor shall reach steady-state conditions. This is continued until thethermal fuse-link fails. This current value is noted. The test is repeated with the other specimenusing 0,95 times the noted value.
I.7.4   Non-short-circuit proof convertors are loaded as indicated in I.7.3. The protective device
specified by the manufacturer is fitted to the relevant input or output circuit.
Associated non-short-circuit-proof convertors are tested under the most unfavourable
conditions of normal use, with the correct protective device specified by the manufacturer fitted
in the input or output circuit, and in the most unfavourable load conditions for the type of
equipment or circuit for which the convertor is designed. Examples of unfavourable load
conditions may be continuous, intermittent or temporary use.61347-2-2  IEC:2000 – 55 –
I.7.5  Fail-safe convertors
I.7.5.1   Three additional specimens are used only for the following test. Convertors used in the
other tests are not subjected to this test.
Each of the three specimens is mounted as for normal use on a 20 mm thick, dull black painted
plywood surface. Each convertor is operated at 1,06 times the rated primary voltage, the output
winding which produced the highest temperature rise during the test of I.6.2 being initially
loaded with 1,5 times rated output current (or, if this is not possible, the maximum value of the
output current obtainable) until steady-state conditions are reached or the convertor fails
(whichever occurs first).
If the convertor fails, it shall comply, during and after the tests, with the criteria in I.7.5.2.
If the convertor does not fail, the time to reach steady-state conditions is noted and the chosen
output winding is then short-circuited. The test is continued until the convertor fails. For this
part of the test, each specimen shall do so within a time not longer than that necessary to
attain steady-state conditions, but not exceeding 5 h.
The convertors shall fail safely and comply during and after the tests with the criteria given
in I.7.5.2.
I.7.5.2  At any time, during the tests of I.7.5.1,
–the temperature rise of any part of the enclosure of the convertors which may be touched
with the standard test finger shall not exceed 150 K;
–the temperature rise of the plywood support shall nowhere exceed 100 K;
–the convertors shall not emit flames, molten material, glowing particles or burning drops of
insulating material.
After the tests of I.7.5.1 and after cooling down to ambient temperature,
–the convertors shall withstand a dielectric strength test, the test voltage being 35 % of the
values given in table I.6, for primary-to-secondary and primary-to-body only;
–enclosures, if any, shall show no holes allowing the standard test finger (see IEC 60529) to
touch bare live parts. In case of doubt, contact with life parts is shown by means of anelectrical contact indicator, the voltage being not less than 40 V.
If one specimen does not pass the test, the complete test is considered as having failed.
I.8  Insulation resistance and electric strength
I.8.1   The insulation resistance and the electric strength of convertors shall be adequate.
Compliance is checked by the tests of clauses 11 and 12 and subclauses I.8.2 and I.8.3, which
are made immediately after the test of clause 11 in the humidity or in the room in which the
specimen was brought to the prescribed temperature, after reassembly of those parts which
may have been removed.61347-2-2  IEC:2000 – 57 –
I.8.2  Insulation resistance is measured with a d.c. voltage of approximately 500 V applied, the
measurement being made 1 min after application of the voltage.
The insulation resistance shall be not less than that shown in table I.5.
Table I.5 – Values of insulation resistances
Insulation to be tested Insulation resistance
MΩ
Between live parts and the body:
–for basic insulation
–for reinforced insulation
Between input circuits and output circuitsBetween metal parts of class II convertors which are separated from live parts by
basic insulation only and the body
Between metal foil in contact with the inner and outer surfaces of enclosures of
insulating material2
45
52
I.8.3   Immediately after the test of I.8.2, the insulation is subjected for 1 min to a voltage of
substantially sine-wave form at rated frequency. The value of the test voltage and the points of
application are given in table I.6.61347-2-2  IEC:2000 – 59 –
Table I.6 – Test voltages
Application of test voltageWorking voltage a
V
≤50 200 <200
≤450700 1 000
Between live parts of input circuits and live
parts of output circuits b500 2 000 3 750 5 000 5 500
Over basic or supplementary insulationbetween
a) live parts which are or may become of
different polarity (for example, by the actionof a fuse);
b) live parts and the body if intended to be
connected to protective earth;
c) accessible metal parts and a metal rod of
the same diameter as the flexible cable orcord (or metallic foil wrapped round thecable cord) inserted inside inlet bushings,cord guards and anchorages and the like;
d) live parts and an intermediate metal part;e) intermediate metal parts and the body.250 1 000 1 875 2 500 2 750
Over reinforced insulation between the body
and live parts500 2 000 3 750 5 000 5 500
a Values of test voltage for intermediate values of working voltage are found by interpolation
between tabulated values, except in the column <200 ≤450, where the values apply without
interpolation.
b These requirements do not apply to circuits separated by an earthed metal screen as
described in I.5.2.4.
Initially, not more than half the prescribed voltage is applied; then, it is raised rapidly to the full
value.
No flashover or breakdown shall occur during the test, corona effects and similar phenomena
being disregarded.
The high-voltage transformer used for the test shall be capable of supplying a current of at
least 200 mA when the output terminals are short-circuited. The overload releases of the circuitshall not operate for any current less than 100 mA. The voltmeter used to measure the r.m.svalue of the test voltage shall be of class 2,5 according to IEC 60051.
Care shall be taken that the voltage applied for test between input and output circuits does not
overstress other insulations. If it is stated by the manufacturer that a double insulation systemexists between primary and secondary windings, such as from primary winding to magneticcore and from magnetic core to secondary winding, each insulation is then tested separately.The same applies to a double insulation between primary and the body.
For class II constructions incorporating both reinforced insulation and double insulation, care
shall be taken that the voltage applied to the reinforced insulation does not overstress thebasic or supplementary insulation.61347-2-2  IEC:2000 – 61 –
I.9  Construction
I.9.1   The construction of convertors shall be such that they comply with all the requirements
of specified applications and be resistant to heat, moisture, water and shock (mechanical and
magnetic).
Compliance is checked by the relevant test.
I.9.2   The input and output terminals for the connection of external wiring shall be so located
that the distance between the clamping units of these terminals is not less than 25 mm. If the
distance is achieved by a barrier, this barrier shall be of insulating material and be permanentlyfixed to the convertor.
Compliance is checked by inspection and by measurement disregarding intermediate metal
parts.
I.10  Components
I.10.1   Sockets-outlets in the output circuit shall not accept plugs complying with IEC 60083,
and IEC 60906-1, neither shall it be possible to engage plugs accepted by socket-outlets in the
output circuit with socket-outlets complying with IEC 60083 and IEC 60906-1.
Compliance is checked by inspection and by manual test.
I.10.2   Self-resetting devices shall not be used unless it is certain that there will be no
hazards.
Compliance is checked by inspection and by connecting the convertor for 48 h (two days) at
1,06 times the rated input voltage with the output terminals short-circuited.
During these tests, no sustained arcing shall occur and there shall be no damage from other
causes. The device shall also operate satisfactorily.
I.11  Creepage distances and clearances
Creepage distances and clearances shall be not less than the values shown in clause 16,
table 3, of IEC 61347-1 and table I.7.
Creepage distances and clearances in table I.7 replace the relevant requirements of
IEC 60598-1, including the illustration of creepage distance and clearance measurements at a
supply terminal as shown in figure 24 of that standard.
The required distances in table I.7 apply to the terminal without conductors inserted.61347-2-2  IEC:2000                                     – 63 –Table I.7 – Creepage distances (cr) and clearances (cl) and distances through insulation (dti)Dimensions in millimetres
Measurement Working voltage a
V
Type of insulationThrough
winding
enamel bOther than
through
winding
enamel/G9450 150 250 440 690 1 000
NPcSP dNP SP cl cr cl cr cl cr cl cr cl cr cl cr
1) Insulation between
input and outputcircuitsa) Creepage distances and
clearances between liveparts of input circuitsand live parts of outputcircuits 
eX
XX
X1,5
1,51,01,01,5
2,01,21,64,0
4,02,72,74,0
5,03,24,06,0
6,04,04,06,0
7,04,85,28,0
8,05,45,48,0
9,76,47,810,0
10,0
6,66,610,0
13,2
8,0
10,611,0
11,0
7,47,411,0
15,4
8,8
12,4
dti dti dti dti dti dti
b) Distances through
insulation between inputor output circuits and anearthed metal screen(see note 2, except that atleast two layers arerequired)XX X X 0 , 1
(0,05)0,25
(0,08)0,5
(0,15)0,65
(0,18)0,75
(0,20)1,0
(0,25)
c) Distances through
insulation between inputand output circuits (seenote 2)XX X X 0 , 2
(0,1)0,5
(0,15)1,0
(0,3)1,3
(0,35)1,5
(0,4)2,0
(0,5)
cl cr cl cr cl cr cl cr cl cr cl cr
2) Insulation between
adjacent input circuitsor insulation betweenadjacent outputcircuits (see note 3)Creepage distance and
clearancesXXXX 0 , 5
0,50,9
0,51,0
0,71,5
1,01,5
1,02,0
1,42,0
1,42,5
1,72,5
1,73,0
2,03,0
2,03,5
2,461347-2-2  IEC:2000                                     – 65 –Table I.7 (continued)Dimensions in millimetres
MeasurementWorking voltage a
V
Type of insulationThrough
winding
enamel bOther than
through
winding
enamel/G9450 150 250 440 690 1 000
NP cSP dNP SP cl cr cl cr cl cr cl cr cl cr cl cr
a) Up to and including
6 AX X X X 3,0 4,0 6,0 8,0 10,0 12,0
b) Over 6 A up to and
including 16 AX X X X 5,0 7,0 10,0 12,0 14,0 16,03) Creepage distances
and clearancesbetween terminalsfor the connection ofexternal cables andcords excludingthose betweenterminals for inputand for outputcircuitsc) Over 16 A X X X X 10,0 12,0 14,0 16,0 18,0 20,0
Between
a) Live parts which are
or may become ofdifferent polarity (forexample by the actionor a fuse)0,8 1,0 2,0 2,0 3,0 3,0 4,0 4,0 5,0 5,0 5,5 5,5
4) Basic or
supplementaryinsulation
b) Live parts and the
body if intended to beconnected toprotective earthX 0,8 1,0 2,0 2,5 3,0 3,5 4,0 4,9 5,0 6,6 5,5 7,7
c) Accessible metal
parts and a metal rodof the same diameteras the flexible cable orcord (or metal foilwrapped around thecable or cord) insertedinside inlet bushings,anchorages and thelike0,5 1,0 1,4 1,6 2,0 2,4 2,7 3,2 3,3 4,0 3,7 4,461347-2-2  IEC:2000                                     – 67 –Table I.7 (continued)Dimensions in millimetres
Measurement Working voltage a
V
Type of insulation Through
winding
enamel bOther than
through
winding
enamel/G9450 150 250 440 690 1 000
NP cSP dNP SP cl cr cl cr cl cr cl cr cl cr cl cr
d) Live parts and an
intermediate metal part
e) An intermediate metalpart and the bodyX 0,5 1,0 1,4 2,0 2,0 2,6 2,7 3,9 3,3 5,8 3,7 6,2
5) Reinforced
insulationBetween the body and live
parts
X
XXX 1 , 5
1,51,01,01,5
2,01,21,64,0
4,02,72,74,0
5,01,24,06,0
6,04,04,06,0
7,04,85,28,0
8,05,45,48,0
9,86,47,810,0
10,0
6,66,610,0
13,2
8,0
10,011,0
11,0
7,47,411,0
15,4
8,8
12,4
dti dti dti dti dti dti
a) Between metal parts
separated bysupplementaryinsulationX X X X 0,5 0,6 0,8 1,0 1,2 1,5
6) Distance through
insulation(excludinginsulation betweeninput and outputcircuits) 
f b) Between metal parts
separated by reinforcedinsulationX X X X 0,7 0,8 1,0 1,5 2,0 2,5
c) Supplementary
insulation where thereare no metal partsadjacent to one of thesurfaces 
eX X X X 0,3 0,4 0,5 0,6 0,8 0,9
d) Reinforced insulation
where there are nometal parts adjacent toone of the surfaces 
eX X X X 0,5 0,6 0,8 1,0 1,2 1,561347-2-2  IEC:2000                                     – 69 –Table I.7 (continued)
NOTE 1  Values for printed wiring where failure may cause a hazard in the sense of this standard, must be the same as values fo r live parts as in the table. Where
printed wiring circuits are for operational purposes only, the values of IEC 60065 for basic insulation (curve A of figure 9) m ay be used.
NOTE 2  The distance throu gh insulation shown in brackets in item 1 of this table may be used provided that the insulation is in thin sheet form and consi sts of at
least three layers and that, with one layer removed, the remaining layer(s) withstand the prescribed electric strength test of I.8.3.
Additional layers may be required if serrated tape is used (see I.5.2.3).For transformers having a rated output greater than 100 VA, the figures in brackets apply.For transformers having a rated output of 25 VA up to and including 100 VA, the figures in brackets may be reduced to two-third s of their value.
For transformers having a rated output less than 25 VA, the figure in brackets may be reduced to one-third of their value.Smaller distances through insulation may be used if it can be shown by the tests of I.6.3 that the materials have adequate mech anical strength and are resistant
to ageing.
NOTE 3  These values do not apply inside each windin
g and do not apply inside each windin g intended to be connected to gether; they do apply, however, if the
windings are intended to be connected in a series-or-parallel arrangement (for example 110/220 V inputs).
NOTE 4  If the pollution generates hi gh and persistent conductivity, caused, for instance, by conductive dust or by rain or snow, the creepa ge distances and
clearances, as given for severe pollution, must be further increased with a minimum clearance of 1,6 mm and a value of X in appendix ID of IEC 60742 of 4,0 mm.
NOTE 5  Windin gs which are sealed by means such as impre gnation or are covered with adhesive bondin g tape which adheres to the flan ges of a coil former, are
considered to have no creepage distances or clearances at these places, provided that all insulating materials are classified a ccording to IEC 60085.
NOTE 6  The requirements concerning distance through insulation do not imply that the prescribed distance shall be through soli d insulation only. It may consist of
a thickness of solid insulation plus one or more air layers.
NOTE 7  Where an insulation barrier consisting of an uncemented, pushed-on partition wall is used, creepage distances are measu red through the joint. If the joint
is covered by an adhesive bonding tape in accordance with IEC 60454, one layer of adhesive bonding tape is required on each sid e of the wall in order to reduce the
risk of tape folding over during production.
NOTE 8  Transformers having a reasonably tight enclosure are considered to have a normal degree of pollution and hermetic seali ng is not required.
aValues of creepa ge distances, clearances and distances throu gh insulation may be found for intermediate values of workin g volta ges by interpolation between
tabulated values.
bMeasurement through winding wire enamel if the winding wire complies with grade 1 of IEC 60317-0-1.
cNP = Normal pollution.
dSP = Severe pollution.
eThis requirement does not apply to windings separated by an earthed metal screen, as described in I.5.2.4
fThis requirement does not apply to supplementary insulation consisting of three layers.
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ICS  29.140.99
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