EN 60238:2004

SLOVENSKI STANDARD
01-junij-2005
1DGRPHãþD
SIST EN 60238:2000
Okovi za žarnice in sijalke z Edisonovim navojem (IEC 60238:2004) (vsebuje
popravek AC:2005)
Edison screw lampholders
Lampenfassungen mit Edisongewinde
Douilles à vis Edison pour lampes
Ta slovenski standard je istoveten z: EN 60238:2004
ICS:
29.140.10 Grla in držala žarnic Lamp caps and holders
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60238
NORME EUROPÉENNE
EUROPÄISCHE NORM December 2004

ICS 29.140.10 Supersedes EN 60238:1998 + A1:1999 + A2:2002
Incorporates Corrigendum January 2005

English version
Edison screw lampholders
(IEC 60238:2004)
Douilles à vis Edison pour lampes Lampenfassungen mir Edisongewinde
(CEI 60238:2004) (IEC 60238:2004)

This European Standard was approved by CENELEC on 2004-10-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

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

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

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60238:2004 E
Foreword
The text of document 34B/1151/FDIS, future edition 8 of IEC 60238, prepared by SC 34B, Lamp caps
and holders, of IEC TC 34, Lamps and related equipment, was submitted to the IEC-CENELEC
parallel vote and was approved by CENELEC as EN 60238 on 2004-10-01.
This European Standard supersedes EN 60238:1998 + corrigendum February 1999 + A1:1999 +
A2:2002 + A2:2002/corrigendum July 2003.
In this edition the new requirements for creepage distances and clearances have been adopted which
are currently circulated by IEC/SC 34D to amend the EN 60598 family of luminaire standards.
Additionally guidances for requirements in EN 61058-1 applicable to switches in lampholders (see
Annex B) and for special requirements in appliance standards (see Annex C) have been included.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2005-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-10-01
Annex ZA has been added by CENELEC.
The contents of the corrigendum of January 2005 have been included in this copy.
__________
Endorsement notice
The text of the International Standard IEC 60238:2004 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60238:2004
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60061 Series Lamp caps and holders together with EN 60061 Series
(mod) gauges for the control of
interchangeability and safety
1) 2)
IEC 60061-1 - Part 1: Lamp caps EN 60061-1 1993
(mod)
1) 2)
IEC 60061-2 - Part 2: Lampholders EN 60061-2 1993
(mod)
1) 2)
IEC 60061-3 - Part 3: Gauges EN 60061-3 1993
(mod)
3)
IEC 60068-2-20 1979 Basic environmental testing procedures HD 323.2.20 S3 1988
Part 2: Tests - Test T: Soldering

4)
IEC 60068-2-32 1975 Part 2: Tests - Test Ed: Free fall EN 60068-2-32  1993

IEC 60068-2-75 1997 Part 2-75: Tests - Test Eh: Hammer tests EN 60068-2-75 1997

5)
IEC 60112 1979 Method for determining the comparative HD 214 S2 1980
and the proof tracking indices of solid
insulating materials under moist
conditions
6)
IEC 60227 Series Polyvinyl chloride insulated cables of - -
rated voltages up to and including
450/750 V
7)
IEC 60245 Series Cables of rated voltages up to and - -
(mod) including 450/750 V and having cross-
linked insulation
1)
Undated reference.
2)
Valid edition at date of issue.
3)
HD 323.2.20 S3 includes A1:1987 to IEC 60068-2-20.
4)
EN 60068-2-32 includes A2:1990 to IEC 60068-2-32.
5)
HD 214 S2 is superseded by EN 60112:2003, which is based on IEC 60112:2003.
6)
The HD 21 series, which is related to, but not directly equivalent with the IEC 60227 series, applies instead.
7)
The HD 22 series, which is related to, but not directly equivalent with the IEC 60245 series, applies instead.

Publication Year Title EN/HD Year
IEC 60335-1 2001 Household and similar electrical EN 60335-1 2002
(mod) appliances - Safety + A11 2004
Part 1: General requirements
IEC 60352-1 1997 Solderless connections EN 60352-1 1997
Part 1: Wrapped connections - General
requirements, test methods and practical
guidance
1) 2)
IEC 60399 - Barrel thread for lampholders with shade EN 60399 2004
holder ring
database
IEC 60417 Graphical symbols for use on equipment - -

IEC 60529 1989 Degrees of protection provided by EN 60529 1991
enclosures (IP Code) + corr. May 1993
A1 1999 A1 2000
IEC 60598 Series Luminaires EN 60598 Series
(mod)
1) 2)
IEC 60598-1 - Part 1: General requirements and tests EN 60598 2004

IEC 60664-1 1992 Insulation coordination for equipment
+ A1 2000 within low-voltage systems
+ A2 2002 Part 1: Principles, requirements and tests EN 60664-1 2003

IEC 60695-2-2 1991 Fire hazard testing – EN 60695-2-2 1994
Part 2: Test methods – Section 2: Needle-
flame test
IEC 60695-2-10 2000 Part 2-10: Glowing/hot-wire based test EN 60695-2-10 2001
methods –
Glow-wire apparatus and common test
procedure
IEC 60695-2-11 2000 Part 2-11: Glowing/hot-wire based test EN 60695-2-11 2001
methods –
Glow-wire flammability test method for end-
products
IEC 61058-1 2000 Switches for appliances –
+ A1 (mod) 2001 Part 1: General requirements EN 61058-1 2002

ISO 4046-4 2002 Paper, board, pulp and related terms – – –
Vocabulary –
Part 4: Paper and board grades and
converted products
NORME CEI
INTERNATIONALE
IEC
INTERNATIONAL
Huitième édition
STANDARD
Eighth edition
2004-10
Douilles à vis Edison pour lampes

Edison screw lampholders
 IEC 2004 Droits de reproduction réservés  Copyright - all rights reserved
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60238  IEC:2004 – 3 –
CONTENTS
FOREWORD.7

1 General.11
2 Definitions.15
3 General requirement.21
4 General conditions for tests .23
5 Standard ratings.25
6 Classification.27
7 Marking.29
8 Dimensions.33
9 Protection against electric shock.37
10 Terminals.41
11 Provision for earthing.49
12 Construction.51
13 Switched lampholders.61
14 Moisture resistance, insulation resistance and electric strength .65
15 Mechanical strength.69
16 Screws, current-carrying parts and connections .77
17 Creepage distances and clearances.81
18 Normal operation.85
19 General resistance to heat .87
20 Resistance to heat, fire and tracking .93
21 Resistance to excessive residual stresses (season cracking) and to rusting .97

Annex A (normative)  Season cracking/corrosion test . 101
Annex B (informative) Guidance for requirements in IEC 61058-1 applicable to switches
in lampholders (see 13.2). 105
Annex C (informative) Guidance for special requirements in appliance standards –
Household and similar electrical appliances. 109

Figure 1a – Nipple thread for lampholders. Basic profile and design profile for the nut
and for the screw . 113
Figure 1b – Nipple thread for lampholders. Basic profile and design profile for the nut
and for the screw . 115
Figure 2a – Gauges for metric ISO thread for nipples . 117
Figure 2b – Gauges for ISO standard pipe thread for nipples . 119
Figure 3 – Gauge for holes for backplate lampholder screws . 121
Figure 4 – Normal operation test apparatus . 123
Figure 5 – Test caps for the test of clause 18 . 125
Figure 6 – Torque apparatus . 127
Figure 7 – Tumbling barrel . 129

60238  IEC:2004 – 5 –
Figure 8 – Impact-test apparatus . 131
Figure 8a – Mounting support . 131
Figure 9 – Pressure apparatus . 133
Figure 10 – Ball-pressure test apparatus . 133
Figure 11 – Test cap for the tests of 14.4 and 19.3 . 135
Figure 12 – Bending apparatus. 137
Figure 13 – Test cap A and test cap B for lampholders E14 . 139
Figure 13 – Test cap A and test cap B for lampholders E14 (continued) . 141
Figure 14 – Test cap for lampholders E27 . 143
Figure 15 – Test cap for lampholders E40 . 145
Figure 16 – Standard test finger (according to IEC 60529) . 147
Figure 17 – Clarification of some definitions . 149
Figure 18 – Preparation of specimens for the needle-flame test of 20.4 . 151

Table 1 – Thickness of screw shells and contacts.35
Table 2 – Minimum effective screw lengths.35
Table 3 – Dimensions of threaded entries and set screws.37
Table 4 – Minimum dimensions of pillar-type terminals .45
Table 5 – Minimum dimensions of screw-type terminals.45
Table 6 – Pull and torque values .57
Table 7 – Insertion torque .61
Table 8 – Minimum and maximum removal torques .61
Table 9 – Test cap dimensions.69
Table 10 – Heights of fall .73
Table 11 – Maximum deformation values.75
Table 12 – Torque values.79
Table 13a – Minimum distances for a.c. (50/60 Hz) sinusoidal voltages Impulse
withstand category II .83
Table 13b – Minimum distances for a.c. (50/60 Hz) sinusoidal voltages Impulse
withstand category III .83
Table 14 – Minimum distances for non-sinusoidal pulse voltages .85
Table 15 – Heating cabinet temperatures .91
Table A.1 – pH adjustment . 101

60238  IEC:2004 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EDISON SCREW LAMPHOLDERS
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 60238 has been prepared by subcommittee 34B: Lamp caps and
holders, of IEC technical committee 34: Lamps and related equipment.
This eighth edition cancels and replaces the seventh edition published in 1998 and its
amendments 1 (1999) and 2 (2002). This eighth edition constitutes a technical revision.
In this edition the new requirements for creepage distances and clearances have been adopted
which are currently circulated by SC34D to amend the IEC 60598 family of luminaire standards.
Additionally guidances for requirements in IEC 61058-1 applicable to switches in lampholders
(see Annex B) and for special requirements in appliance standards (see Annex C) have been
included.
60238  IEC:2004 – 9 –
The text of this standard is based on the following documents:
FDIS Report on voting
34B/1151/FDIS 34B/1170/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result 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.
60238  IEC:2004 – 11 –
EDISON SCREW LAMPHOLDERS
1 General
1.1 Scope
This International Standard applies to lampholders with Edison thread E14, E27 and E40,
*
designed for connection to the supply of lamps and semi-luminaires only.
It also applies to switched-lampholders for use in a.c. circuits only, where the working voltage
does not exceed 250 V r.m.s.
This standard also applies to lampholders with Edison thread E5 designed for connection to the
supply mains of series connected lamps, with a working voltage not exceeding 25 V, to be used
indoors, and to lampholders with Edison thread E10 designed for connection to the supply
mains of series connected lamps, with a working voltage not exceeding 60 V, to be used
indoors or outdoors. It also applies to lampholders E10 for building-in, for the connection of
single lamps to the supply. These lampholders are not intended for retail sale.
As far as it reasonably applies, this standard also covers lampholders other than lampholders
with Edison thread designed for connection of series-connected lamps to the supply.
NOTE This type of lampholder is for example used in Christmas tree lighting chains.
As far as it reasonably applies, this standard also covers adapters.
This standard also covers lampholders which are, wholly or partly, integral with a luminaire or
intended to be built into appliances. It covers the requirements for the lampholder only. For all
other requirements, such as protection against electric shock in the area of the terminals or of
the lamp cap, the requirements of the relevant appliance standard shall be observed and
tested after building into the appropriate equipment, when that equipment is tested according to
its own standard. Such lampholders as well as lampholders provided with a snap-on outer
shell, for use by luminaire manufacturers only, are not for retail sale.
This standard applies to lampholders to be used indoors or outdoors in residential as well as in
industrial lighting installations. It also applies to candle lampholders. In locations where special
conditions prevail, as for street lighting, on board ships, in vehicles and in hazardous locations,
e.g. where explosions are liable to occur, special constructions may be required.
NOTE 1 This standard does not apply to three-light lampholders E26d.
NOTE 2 This standard is based on the following data relative to lamps for general lighting service:
– caps E14 are used for lamps with a current not exceeding 2 A;
– caps E27 are used for lamps with a current not exceeding 4 A;
– caps E40 are used for lamps with a current not exceeding 16 A.
NOTE 3 If the nominal voltage of the supply does not exceed 130 V, the maximum current for caps E40 is 32 A
(see 4.5 and 5.3).
NOTE 4 Where lampholders are used in luminaires, their maximum operating temperatures are specified in
IEC 60598.
___________
*
Requirements for lampholders suitable for semi-luminaires are under consideration.

60238  IEC:2004 – 13 –
1.2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
NOTE With regard to IEC 60598-1, the references cited in this document are liable to change.
IEC 60061 (all parts), Lamp caps and holders together with gauges for the control of
interchangeability and safety
IEC 60061-1: Lamp caps and holders together with gauges for the control of interchangeability
and safety – Part 1: Lamp caps
IEC 60061-2: Lamp caps and holders together with gauges for the control of interchangeability
and safety – Part 2: Lampholders
IEC 60061-3: Lamp caps and holders together with gauges for the control of interchangeability
and safety – Part 3: Gauges
IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering
IEC 60068-2-32:1975, Environmental testing – Part 2: Tests – Test Ed: Free fall
IEC 60068-2-75:1997, Environmental testing – Part 2: Tests – Test Eh: Hammer tests
IEC 60112:1979, Method for determining the comparative and the proof tracking indices of solid
insulating materials under moist conditions
IEC 60227 (all parts), Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V
IEC 60245 (all parts), Rubber insulated cables – Rated voltages up to and including 450/750 V
IEC 60335-1:2001, Household and similar electrical appliances – Safety – Part 1: General
requirements
IEC 60352-1:1997, Solderless connections – Part 1: Wrapped connections – General require-
ments, test methods and practical guidance
IEC 60399, Barrel thread for lampholders with shade holder ring
**)
IEC 60417-DB:2002 Graphical symbols for use on equipment
*)
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
Amendment 1 (1999)
IEC 60598 (all parts and sections), Luminaires
IEC 60598-1: Luminaires – Part 1: General requirements and tests
IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1:
***)
Principles, requirements and tests
Amendment 1 (2000)
Amendment 2 (2002)
___________
)
* A consolidated edition 2.1 (2001) exists including edition 2.0 (1989) and its amendment 1(1999).

**) “DB” refers to the IEC on-line database.
***)
A consolidated edition 1.2 (2002) exists including edition 1.0 (1992) and its amendment 1 (2000) and
amendment 2 (2002).
60238  IEC:2004 – 15 –
IEC 60695-2-2:1991, Fire hazard testing – Part 2: Test methods – Section 2: Needle-flame test
IEC 60695-2-10:2000, Fire hazard testing – Part 2–10: Glowing/hot-wire based test methods –
Glow-wire apparatus and common test procedure
IEC 60695-2-11:2000, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end products
IEC 61058-1:2000, Switches for appliances – Part 1: General requirements
ISO 4046-4:2002, Paper, board, pulps and related terms – Vocabulary – Part 4: Paper and
board grades and converted products
2 Definitions
For the purpose of this International Standard, the following definitions apply. For clarification
of some definitions, see also figure 17.
2.1
cord-grip lampholder
a lampholder incorporating a method of retaining a flexible cord by which it may then be
suspended
2.2
threaded entry lampholder
a lampholder incorporating a threaded component at the point of entry of the supply wires
permitting the lampholder to be mounted on a mating threaded support (formerly called "nipple
lampholder")
2.3
backplate lampholder
a lampholder so designed as to be suitable for mounting by means of an associated or integral
back plate, directly onto a supporting surface or appropriate box
2.4
lampholder for building-in
a lampholder designed to be built into a luminaire, an additional enclosure or the like
2.4.1
unenclosed lampholder
a lampholder for building-in so designed that it requires additional means, for example an enclo-
sure, to meet the requirements of this standard with regard to protection against electric shock
2.4.2
enclosed lampholder
a lampholder for building-in so designed that on its own it fulfils the requirements of this
standard with regard to protection against electric shock and IP classification, if appropriate
2.5
independent lampholder
a lampholder so designed that it can be mounted separately from a luminaire and at the same
time providing all the necessary protection according to its classification and marking

60238  IEC:2004 – 17 –
2.6
terminal/contact assembly
a part or assembly of parts which provide(s) a means of connection between the termination
of a supply conductor and the contact making surfaces of the corresponding lamp cap
2.7
outer shell
a cylindrical component protecting the user from contact with the lamp cap. It may or may not
be provided with an external screw thread for fixing a shade ring
2.7.1
snap-on outer shell
an outer shell for screwless assembly which does not contain the screw shell
NOTE The lampholder should not be used when the snap-on outer shell is removed.
It is therefore recommended to place an approval mark, if provided, in such a way that it is not visible when this
type of outer shell is removed.
2.8
screw shell
a cylindrical component having an internal screw thread of Edison form for the retention of the
corresponding lamp (cap)
In some constructions, the screw shell is permanently fixed to or integral with the outer shell.
2.9
insulating ring
a cylindrical intermediate piece of insulating material separating a metal screw shell and a
metal outer shell
2.10
shade ring
a cylindrical component having an internal thread or other means to engage a corresponding
support on the outer shell and intended to carry or retain a shade

2.11
dome
a part of a cord-grip lampholder or threaded entry lampholder which shields the connecting
terminals
2.12
basic insulation
an insulation applied to live parts to provide basic protection against electric shock
NOTE Basic insulation does not necessarily include insulation used exclusively for functional purposes.
2.13
supplementary insulation
an independent insulation applied in addition to basic insulation in order to provide protection
against electric shock in the event of a failure of basic insulation
2.14
double insulation
an insulation comprising both basic insulation and supplementary insulation

60238  IEC:2004 – 19 –
2.15
reinforced insulation
a single insulation system applied to live parts, which provides a degree of protection against
electric shock equivalent to double insulation under the conditions specified
NOTE The term "insulation system" does not imply that the insulation must be one homogeneous piece. It may
comprise several layers which cannot be tested singly as supplementary or basic insulation.
2.16
live part
a conductive part which may cause an electric shock
2.17
type test
a test or series of tests made on a type test sample, for the purpose of checking compliance of
the design of a given product with the requirements of the relevant standard
2.18
type test sample
a sample consisting of one or more similar specimens submitted by the manufacturer or
responsible vendor for the purpose of a type test
2.19
semi-luminaire
a unit similar to a self-ballasted lamp but designed to utilize a replaceable light source and/or
starting device
2.20
rated operating temperature
the highest temperature for which the holder is designed
2.21
rated minimum temperature
the lowest temperature for which the holder is designed (applicable only to lampholders
intended for use in refrigerators and food freezers)
2.22
angled lampholder
lampholder, the rear side of which (threaded entry and/or dome) is at an angled position to the
screw shell axis
2.23
lampholder with retention device
lampholder with a device intended to prevent the lamp from becoming loose in the holder
NOTE Lamps may, for example, become loose due to changes in temperature or to vibrations.

60238  IEC:2004 – 21 –
2.24
impulse withstand categories
a numeral defining a transient overvoltage condition
NOTE Impulse withstand categories I, II, III and IV are used.
a) Purpose of classification of impulse withstand categories
Impulse withstand categories are to distinguish different degrees of availability of equipment with regard to required
expectations on continuity of service and on an acceptable risk of failure.
By selection of impulse withstand levels of equipment insulation co-ordination can be achieved in the whole
installation, reducing the risk of failure to an acceptable level providing a basis for overvoltage control.
A higher characteristic numeral of an impulse withstand category indicates a higher specific impulse withstand of
the equipment and offers a wider choice of methods for overvoltage control.
The concept of impulse withstand categories is used for equipment energized directly from the mains.
b) – Description of impulse withstand categories
Equipment of impulse withstand category I is equipment which is intended to be connected to the fixed electrical
installations of buildings. Protective means are taken outside the equipment – either in the fixed installation or
between the fixed installation and the equipment – to limit transient overvoltages to the specific level.
Equipment of impulse withstand category II is equipment to be connected to the fixed electrical installations of
buildings.
Equipment of impulse withstand category III is equipment which is part of the fixed electrical installations and other
equipment where a higher degree of availability is expected.
Equipment of impulse withstand category IV is for use at or in the proximity of the origin of the electrical
installations of buildings upstream of the main distribution board.

2.25
primary circuit
a circuit which is directly connected to the AC mains supply. It includes, for example, the
means for connection to the AC mains supply, the primary windings of transformers, motors
and other loading devices
2.26
secondary circuit
a circuit which has no direct connection to a primary circuit and derives its power from a
transformer, converter or equivalent isolation device, or from a battery
Exception: autotransformers. Although having direct connection to a primary circuit, the tapped
part of them is also deemed to be a secondary circuit in the sense of this definition.
NOTE Mains transients in such a circuit are attenuated by the corresponding primary windings. Also inductive
ballasts reduce the mains transient voltage height. Therefore, components located after a primary circuit or after an
inductive ballast can be suited for an impulse withstand category of one step lower, i.e. for impulse withstand
category II.
2.27
adapter
a component used for the electrical and mechanical connection of a lamp to a lampholder
NOTE This definition is specific for this standard. The definition of an adapter in principle could vary very much
depending on its use. In most cases such a component is used to bridge differences in the screw thread diameter
between the lampholder and the lamp.
3 General requirement
Lampholders shall be so designed and constructed that in normal use they function reliably and
cause no danger to persons or surroundings.
In general, compliance is checked by carrying out all the tests specified.
In addition, the enclosure of independent lampholders shall comply with the requirements of
IEC 60598-1, including the classification and marking requirements of that standard.

60238  IEC:2004 – 23 –
4 General conditions for tests
4.1 Tests according to this standard are type tests.
NOTE The requirements and tolerances permitted by this standard are related to testing of a type test sample
submitted for that purpose.
Compliance of the type test sample does not ensure compliance of the whole production of a manufacturer with this
safety standard.
In addition to type testing, conformity of production is the responsibility of the manufacturer and may include routine
tests and quality assurance.
*****)
For further information see IEC 60061-4 (inclusion of guidance on conformity testing during manufacture is in
preparation).
4.2 Unless otherwise specified, the tests are made at an ambient temperature of 20 °C ± 5 °C
and with the holder tested as delivered and installed as in normal use.
4.3 The tests and inspections are carried out on a total of
– nine specimens for non-switched lampholders, or
– 12 specimens for switched lampholders
in the following order of clauses:
– three specimens clauses 1 to 12 (except for 9.1 and 10.2) and 14 to 17;
– three specimens clause 13 (switched-lampholder tests only);
– three specimens subclause 9.1 and clauses 18 and 19;
– two specimens clause 20 (of which one specimen for the test of 20.1 and the other for the
tests of 20.3 or 20.4);
– one specimen 20.5 and clause 21.
For testing lampholders with a retention device, the retention device shall be removed.
For testing lampholders with a retention device according to 12.14, three additional specimens
are required with the retention device kept in place.
NOTE For testing of screwless terminals according to 10.2, separate specimens are required in addition.
4.4 In case of doubt, gauges, test caps and mandrels are introduced into the specimens,
unless otherwise specified, by applying the following torques:
– 0,2 Nm for lampholders E5;
– 0,2 Nm for lampholders E10;
– 0,2 Nm for lampholders E14;
– 0,4 Nm for lampholders E27;
– 0,8 Nm for lampholders E40.
4.5 For lampholders E40 with a rated current of 32 A, the tests shall be based on this rated
current.
4.6 Lampholders are deemed to comply with this standard if no specimen fails in the complete
series of tests specified in 4.3.
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)
****
IEC 60061-4: Lamp caps and holders together with gauges for the control of interchangeability and safety –
Part 4: Guidelines and general information

60238  IEC:2004 – 25 –
If one specimen fails in one test, that test and the preceding ones which may have influenced
the result of that test are repeated on another set of specimens to the number required by 4.3,
all of which shall then comply with the repeated tests and with the subsequent tests.
Lampholders are deemed not to comply with this standard if there are more failures than one.
NOTE In general, it will only be necessary to repeat the relevant test unless the specimen fails in the tests
according to clauses 18 and 19, or if failure occurs with regard to resilient side or central contact(s); in these cases,
both tests are repeated with a second set of three specimens.
The applicant may submit, together with the first set of specimens, the additional set which may be wanted in case
of failure of one specimen. The testing station shall then, without further request, test the additional specimens and
will reject only if a further failure occurs.
If the additional set of specimens is not submitted at the same time, a failure of one specimen entails a rejection.
5 Standard ratings
5.1 Standard rated voltages are: 250 V, 500 V and 750 V.
For lampholders E14, and for switched lampholders E27, a rated voltage of 250 V only is
allowed.
For lampholders E5 and E10 intended for the connection of series-connected lamps to the
supply, the rated voltage shall not exceed 25 V for lampholders E5 and not exceed 60 V for
lampholders E10.
NOTE These values refer to the voltage between parts of different polarity.
For lampholders E10 intended for the connection of single lamps to the supply, a rated voltage
of 250 V only is allowed.
NOTE These lampholders should also be used for such special cases as series-connected lamps, whereby the low
number of lamps 60 V per lampholder is exceeded.
With the exception given for lampholders E5 and E10 the rated voltage shall be not less than
250 V. Additionally a rated voltage of 125 V is allowed for lampholders E40.
Compliance is checked by inspection of the marking.
5.2 Standard rated currents are
– 0,2 A for lampholders E5;
– 0,5 A for lampholders E10;
– 2 A for lampholders E14;
– 2 A for switched-lampholders E27;
– 4 A for other lampholders E27;
– 16 A for lampholders E40.
The rated current shall be not less than the standard value.
Compliance is checked by inspection of the marking.
5.3 Lampholders E40 to be used on 125 V (see note) installations may have an additional
nominal rating of 32 A.
NOTE This nominal rating covers the voltages up to and including 130 V.
Compliance is checked by inspection of the marking.

60238  IEC:2004 – 27 –
5.4 The rated operating temperature for lampholders intended for use in high temperature
conditions (T marked holders) shall be not lower than 140 °C for E14 lampholders, not lower
than 170 °C for E27 lampholders and not lower than 230 °C for lampholders E40.
NOTE The values of the temperature marking should be increased by steps of 10 °C.
Compliance is checked by inspection of the marking.
NOTE The rated operating temperatures for Edison screw lampholders without T marking are given in IEC 60598-1,
table 12.1. They are
– 135 °C for lampholders E14;
– 165 °C for lampholders E27;
– 225 °C for lampholders E40.
6 Classification
Lampholders are classified:
6.1 According to the material of the external parts:
– lampholders of insulating material;
– metal lampholders.
NOTE Lampholders with external parts consisting partly of metal and lampholders comprising external parts of
insulating material with a conductive outer surface, for example a metallized outer shell, are considered as metal
lampholders (see 12.3). This does not apply to threaded entries and external parts, as for example a metal shade
ring mounted onto the outside of a lampholder of insulating material, which cannot become live even in the case of
an insulation fault. Metal holders with insulating coverings are considered as metal lampholders (see 9.5).
In order to check whether or not a surface is conductive, two stripe-electrodes 1,5 mm wide,
25 mm long and with a distance of 2 mm from each other are applied to the surface (e.g. with
silver conductive paint). In accordance with 14.4, the insulating resistance is measured
between the stripes. The surface is considered to be conductive if the resistance is less than
5 MΩ.
6.2 According to degree of protection against ingress of water:
– ordinary lampholders;
– drip-proof lampholders.
6.3 According to method of fixing:
– threaded entr
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