IEC 60352-7:2026

IEC 60352-7 ®
Edition 3.0 2026-01
INTERNATIONAL
STANDARD
REDLINE VERSION
Solderless connections -
Part 7: Spring clamp connections - General requirements, test methods and
practical guidance
ICS 31.220.10 ISBN 978-2-8327-0996-2
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either
IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright
or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local
IEC member National Committee for further information.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.
replaced and withdrawn publications.
Electropedia - www.electropedia.org
The world's leading online dictionary on electrotechnology,
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: sales@iec.ch.
IEC 60352-7:2025 RLV © IEC 2025
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Requirements . 11
4.1 WorkmanshipQuality of work . 11
4.2 Tools . 11
5 Pre-requisites for basic test schedule . 12
5.1 Spring clamp terminations . 12
5.1.1 Materials . 12
5.1.2 Surface finishes . 12
5.1.3 Design features . 12
5.1.4 Dimensions . 12
5.2 Wires . 12
5.2.1 General . 12
5.2.2 Materials . 12
5.2.3 Dimensions . 12
5.2.4 Surface finishes . 13
5.2.5 Wire insulation . 13
5.3 Spring clamp connections . 13
6 Testing . 13
6.1 General . 13
6.2 Standard conditions for testing . 13
6.3 Preconditioning . 13
6.4 Recovery . 14
6.5 Mounting of specimen . 14
7 Tests . 14
7.1 General examination . 14
7.2 Mechanical tests . 14
7.2.1 Tensile strength . 14
7.2.2 Wire deflection . 15
7.2.3 Vibration . 17
7.2.4 Repeated connections and disconnections . 18
7.3 Electrical tests . 18
7.3.1 Contact resistance . 18
7.3.2 Electrical load and temperature . 20
7.4 Climatic tests . 20
7.4.1 General . 20
7.4.2 Rapid change of temperature . 20
7.4.3 Climatic sequence . 21
7.4.4 Flowing mixed gas corrosion test . 21
8 Test schedules . 21
8.1 General . 21
8.2 Basic test schedule . 22
8.2.1 General . 22
IEC 60352-7:2025 RLV © IEC 2025
8.2.2 Initial examination. 22
8.2.3 Testing of spring clamp connections with spring clamp terminations with
and without a specified wire range . 22
8.3 Full test schedule . 23
8.3.1 General . 23
8.3.2 Initial examination. 23
8.3.3 Testing of spring clamp connections with and without a specified wire
range . 23
8.4 Flow charts . 25
Annex A (informative) Practical guidance . 30
A.1 Current-carrying capacity . 30
A.2 Tool information . 30
A.3 Termination information . 30
A.3.1 General . 30
A.3.2 Design features . 30
A.3.3 Materials . 31
A.3.4 Surface finishes . 31
A.4 Wire information . 31
A.4.1 General . 31
A.4.2 Materials . 32
A.4.3 Surface finishes . 32
A.4.4 Stripping information. 32
A.5 Connection information . 33
Annex B (normative) Tests for resiliency in metallic parts to compensate for any
shrinkage or yielding of insulating material with regards to contact pressure transmitted
via insulating material (CoPI) . 35
B.1 Ageing test sequence for connections with contact pressure via insulating
material . 35
B.2 Cold storage (preconditioning step 1) . 37
B.3 Dry heat storage (preconditioning step 2). 37
B.4 Current cycling ageing test procedure . 37
Bibliography . 39

Figure 1 – Examples of spring clamp connections . 10
Figure 2 – Example of a spring clamp terminal . 10
Figure 3 – Example of a spring clamp connecting device with CoPI . 11
Figure 4 – Information for the Test arrangement, wire deflection . 17
Figure 5 – Test arrangement, vibration . 17
Figure 6 – Test arrangement, current method . 19
Figure 7 – Basic test schedule (see 8.2) . 27
Figure 8 – Full test schedule (see 8.3) . 29
Figure A.1 – Correctly stripped wire . 32
Figure A.2 – Examples of stripping faults . 33
Figure B.1 – Examples of spring clamp terminal with contact pressure via insulating
material with solid (left) and flexible wire (right) . 35
Figure B.2 – Test sequence CoPI . 36
Figure B.3 – Test assembly for the voltage-drop measurement . 36
Figure B.4 – Current cycling ageing test procedure . 38
IEC 60352-7:2025 RLV © IEC 2025
Table 1 – Values of tensile strength . 14
Table 2 – Value of force for wire deflection test . 16
Table 3 – Vibration, test severities . 18
Table 4 – Rated current of the wires, initial and final contact resistance. 20
Table 5 – Number of specimens required . 22
Table 6 – Test group P1 . 22
Table 7 – Test group P2 . 23
Table 8 – Test group A . 23
Table 9 – Test group B . 24
Table 10 – Test group C . 24
Table 11 – Test group D . 24

IEC 60352-7:2025 RLV © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Solderless connections -
Part 7: Spring clamp connections -
General requirements, test methods and practical guidance

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of a patent, which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes made
to the previous edition IEC 60352-7:2020. A vertical bar appears in the margin wherever a
change has been made. Additions are in green text, deletions are in strikethrough red text.

IEC 60352-7:2025 RLV © IEC 2025
IEC 60352-7 has been prepared by subcommittee 48B: Electrical connectors, of IEC technical
committee 48: Electrical connectors and mechanical structures for electrical and electronic
equipment. It is an International Standard.
This third edition cancels and replaces the second edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Addition of definition 3.6 contact pressure via insulating material CoPI;
b) Addition of definition 3.7 spring clamp connecting device with CoPI;
c) Addition of a dedicated test group for spring clamp connections made with spring clamp
terminations, which achieve contact pressure through insulating material (CoPI), which shall
be tested according to Annex B in Subclause 6.1;
d) Addition of test group “CoPI” in Clause 8;
e) Addition of Annex B to detail tests for resiliency in metallic parts to compensate for any
shrinkage or yielding of insulating material with regards to contact pressure transmitted
through the insulating material (CoPI), referenced in the “Test group CoPI” added in both
test schedules.
The text of this International Standard is based on the following documents:
Draft Report on voting
48B/3177/FDIS 48B/3186/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60352 series, published under the general title Solderless
connections, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
IEC 60352-7:2025 RLV © IEC 2025
INTRODUCTION
This part of IEC 60352 covers spring clamp connections and includes requirements, tests and
practical guidance information.
Two test schedules are provided.
a) The basic test schedule applies to spring clamp connections which conform to all
requirements of Clause 5. These requirements are derived from experience with successful
applications of such spring clamp connections.
b) The full test schedule applies to spring clamp connections which do not fully conform to all
requirements of Clause 5, for example which are manufactured using materials or finishes
not included in Clause 5.
This approach ensures cost and time effective performance verification using a limited basic
test schedule for established spring clamp connections and an expanded full test schedule for
spring clamp connections requiring more extensive performance validation.
In this third edition, a dedicated test group providing requirements and tests for spring clamp
connections with contact pressure transmitted via insulating material (CoPI) has been added in
both test schedules, referring to the new Annex B (normative). In such instance, this provides
means to fulfil both the requirement of 6.6.3 of IEC 61984:2008 concerning the design of
electrical connections of connectors, and the requirement of 8.2 of IEC 60999-1:1999
concerning the design of clamping units connecting devices.
The values given in this document are minimum values, which are harmonized with other IEC
documents. Other standardsor the manufacturer’s specification may can specify other values.
The test procedure for resiliency in metallic parts to compensate for any shrinkage or yielding
of insulating material with regards to contact pressure transmitted via insulating material (CoPI)
has been derived from IEC 60947-7-4:2019.

IEC 60352-7:2025 RLV © IEC 2025
1 Scope
This part of IEC 60352 is applicable to spring clamp connections made with stripped wire of the
following types and sizes according to IEC 60228 or IEC 60189-3, without further preparation
(later described “unprepared”):
– solid conductors (e.g. class 1 of IEC 60228) of 0,32 mm to 3,7 mm nominal diameter
2 2
(0,08 mm to 10 mm cross-section), or
2 2
– stranded conductors (e.g. class 2 of IEC 60228) of 0,08 mm to 10 mm cross-section, or
2 2
– flexible conductors (e.g. class 5 or 6 of IEC 60228) of 0,08 mm to 10 mm cross-section,
according to IEC 60228 or IEC 60189-3 for use in electrical and electronic equipment and
components.
Information on materials and data from industrial experience is included in addition to the test
procedures to provide electrically stable connections under prescribed environmental
conditions.
The object of this document is to determine the suitability of spring clamp connections under
specified mechanical, electrical and atmospheric conditions.
NOTE IEC Guide 109 advocates the need to minimize the impact of a product on the natural environment throughout
the product life cycle. It is understood that some of the materials permitted in this document can have a negative
environmental impact. As technological advances lead to acceptable alternatives for these materials, they will be
eliminated from this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-581, International Electrotechnical Vocabulary (IEV) - Part 581: Electromechanical
components for electronic equipment
IEC 60068-1:2013, Environmental testing - Part 1: General and guidance
IEC 60189-3:2007, Low-frequency cables and wires with PVC insulation and PVC sheath -
Part 3: Equipment wires with solid or stranded conductor wires, PVC insulated, in singles,
pairs and triples
IEC 60228:2004, Conductors of insulated cables
IEC 60512-1, Connectors for electrical and electronic equipment - Tests and measurements -
Part 1: Generic specification
IEC 60512-1-1, Connectors for electronic equipment - Tests and measurements -
Part 1-1: General examination - Test 1a: Visual examination
IEC 60512-1-2, Connectors for electronic equipment - Tests and measurements -
Part 1-2: General examination - Test 1b: Examination of dimension and mass
IEC 60512-2-1, Connectors for electronic equipment - Tests and measurements -
Part 2-1: Electrical continuity and contact resistance tests - Test 2a: Contact resistance -
Millivolt level method
IEC 60352-7:2025 RLV © IEC 2025
IEC 60512-2-2:2003, Connectors for electronic equipment - Tests and measurements -
Part 2-2: Electrical continuity and contact resistance tests - Test 2b: Contact resistance -
Specified test current method
IEC 60512-2-5, Connectors for electronic equipment - Tests and measurements -
Part 2-5: Electrical continuity and contact resistance tests - Test 2e: Contact disturbance
IEC 60512-6-4, Connectors for electronic equipment - Tests and measurements -
Part 6-4: Dynamic stress tests - Test 6d: Vibration (sinusoidal)
IEC 60512-9-2, Connectors for electronic equipment – Tests and measurements – Part 9-2:
Endurance tests – Test 9b: Electrical load and temperature
IEC 60512-9-5, Connectors for electrical and electronic equipment - Tests and measurements -
Part 9-5: Endurance tests - Test 9e: Current loading, cyclic
IEC 60512-11-1, Connectors for electrical and electronic equipment - Tests and measurements -
Part 11-1: Climatic tests - Test 11a - Climatic sequence
IEC 60512-11-4, Connectors for electronic equipment - Tests and measurements -
Part 11-4: Climatic tests - Test 11d: Rapid change of temperature
IEC 60512-11-7, Connectors for electronic equipment - Tests and measurements -
Part 11-7: Climatic tests - Test 11g: Flowing mixed gas corrosion test
IEC 60512-11-9, Connectors for electronic equipment - Tests and measurements -
Part 11-9: Climatic tests - Test 11i: Dry heat
IEC 60512-11-10, Connectors for electronic equipment - Tests and measurements -
Part 11-10: Climatic tests - Test 11j: Cold
IEC 60512-16-20, Electromechanical components for electronic equipment - Basic testing
procedures and measuring methods - Part 16: Mechanical tests on contacts and terminations -
Section 20: Test 16t: Mechanical strength (wired termination of solderless connections)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-581,
IEC 60512-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
spring clamp termination
part of the contact or terminal to which one single conductor only is connected by means of a
spring
IEC 60352-7:2025 RLV © IEC 2025
3.1.1
universal spring clamp termination
spring clamp termination intended to accept solid, stranded and flexible unprepared conductors
Note 1 to entry: For the meaning of solid, stranded and flexible, see IEC 60228 where conductors are classified as
class 1 (solid conductors), class 2 (stranded conductors), class 5 (flexible conductors) and class 6 (flexible
conductors which are more flexible than class 5).
3.1.2
non-universal spring clamp termination
spring clamp termination intended to accept conductors of one class only, for example solid
conductors only, or conductors of two classes only, for example solid and stranded but not
flexible
Note 1 to entry: For the meaning of solid, stranded and flexible, see IEC 60228 where conductors are classified as
class 1 (solid conductors), class 2 (stranded conductors), class 5 (flexible conductors) and class 6 (flexible
conductors which are more flexible than class 5).
3.1.3
push-in spring clamp termination
non-universal spring clamp termination in which the connection is made by pushing in a solid
or stranded conductor without the aid of a tool or of an actuating element
Note 1 to entry: For the meaning of solid and stranded, see IEC 60228 where solid conductors are classified as
class 1, stranded conductors are classified as class 2.
Note 2 to entry: Flexible conductor ends can become solid by e.g. ultrasonic welding according to IEC 60352-9.
3.2
spring clamp connection
solderless connection achieved by clamping a conductor with a spring clamp termination
Note 1 to entry: See Figure 1.
IEC 60352-7:2025 RLV © IEC 2025

a) Spring clamp connection, operated without a tool

b) Spring clamp connection, operated with a tool

c) Spring clamp connection, operated with an actuating element

d) Spring clamp connections, with a push-in spring clamp termination, with solid wires
Figure 1 – Examples of spring clamp connections
3.3
spring clamp terminal
terminal designed to accept a conductor for the purpose of establishing a spring clamp
connection
Note 1 to entry: See Figure 2.

Figure 2 – Example of a spring clamp terminal
IEC 60352-7:2025 RLV © IEC 2025
3.4
spring clamp connecting device
device for the electrical connection of one or more conductors comprising one or more spring
clamp terminations and, if necessary, either insulation and/or auxiliary parts, or both
3.5
actuating element
part of a spring clamp termination or terminal to which an external force is to be applied, and
the resulting movement of which provides a means for activating or deactivating the spring
Note 1 to entry: Movement of the actuating element provides a means for activating or deactivating the spring.
3.6
contact pressure via insulating material
CoPI
contact pressure due to contact force transmitted through insulating material
3.7
spring clamp connecting device with CoPI
spring clamp connecting device where the electrical connection of one or more conductors
depends on contact pressure transmitted via insulating material with sufficient resiliency in the
metallic parts to assure necessary contact pressure
Note 1 to entry: See Figure 3.

Figure 3 – Example of a spring clamp connecting device with CoPI
4 Requirements
4.1 WorkmanshipQuality of work
The connection shall be processed in a careful and workmanlike professional manner, in
accordance with good current practice. Annex A (informative) provides practical guidance and
may can constitute a benchmark for the assessment of workmanship the quality of work.
NOTE Some industry sectors (e.g. automotive, aerospace, marine, nuclear, military) use workmanship standards
for the quality of work which can be considered upon agreement between manufacturer and user.
4.2 Tools
Tools, if necessary, shall be used and inspected according to the instructions given by the
manufacturer.
IEC 60352-7:2025 RLV © IEC 2025
5 Pre-requisites for basic test schedule
5.1 Spring clamp terminations
5.1.1 Materials
– Materials for the current-carrying parts:
Suitable grades of copper or copper alloy shall be used.
– Materials for the spring clamp parts:
Suitable (according to manufacturer´s instructions) grades of copper alloy or steel shall be
used.
5.1.2 Surface finishes
The contact area of the current-carrying parts shall be plated with tin or tin-alloy.
The surface shall be free of detrimental contamination or corrosion.
5.1.3 Design features
Spring clamp terminations shall be designed so that the spring clamp parts establish a force to
connect the conductors which ensures that the necessary contact pressure is maintained.
In a spring clamp connecting device, each conductor shall be clamped individually.
The openings for use of a tool intended to assist the insertion or withdrawal of the conductor
shall be clearly distinguishable from the conductor’s entry hole.
5.1.4 Dimensions
The suitability of a spring clamp connection depends on the dimensions of the termination
together with the characteristics of the materials used.
The dimensions of the termination shall be chosen so as to be suitable for (i.e. able to accept)
the cross-sectional area of the conductor or the range of conductors for which the termination
is designed.
The suitability is verified by applying the test schedules given in Clause 8.
5.2 Wires
5.2.1 General
Wires with solid, stranded and flexible conductors according to IEC 60228 or IEC 60189-3 shall
be used depending on the type of spring clamp terminations.
5.2.2 Materials
The conductor used shall be made of annealed copper.
5.2.3 Dimensions
Wires with the following dimensions shall be used:
2 2
– solid wires of 0,32 mm to 3,7 mm nominal diameter (0,08 mm to 10 mm cross-section), or
2 2
– stranded wires of 0,08 mm to 10 mm cross-section, or
2 2
– flexible wires of 0,08 mm to 10 mm cross-section.
IEC 60352-7:2025 RLV © IEC 2025
5.2.4 Surface finishes
The conductor shall be unplated or plated with tin or tin-alloy.
The conductor surface shall be free of contamination and corrosion which degrades
performance.
5.2.5 Wire insulation
The insulation shall be capable of being readily stripped from the conductor without changing
the physical characteristics of the conductor or strands.
5.3 Spring clamp connections
a) The combination of conductor and spring clamp termination shall be compatible.
b) The wire shall be stripped to the correct length specified by the manufacturer. The stripped
part of the wire shall not be damaged and shall be clean and free from particles of insulation.
c) The conductor shall be correctly located in the spring clamp termination at the correct depth
specified by the manufacturer.
All strands of the wire shall be within the spring clamp termination.
6 Testing
6.1 General
As explained in the introduction, there are two test schedules which The test schedule to be
applied shall be applied chosen according to the following conditions:
a) spring clamp connections which conform to all the requirements of Clause 5 shall be tested
in accordance with and meet the requirements of the basic test schedule, see 8.2;
b) spring clamp connections which do not fully conform to all the requirements of Clause 5, for
example, those which are made with different wire types and/or termination sizes and/or
materials, shall be tested and meet the requirements of the full test schedule given in 8.3;
Both these test schedules include a dedicated test group for spring clamp connections made
with spring clamp terminations which have contact pressure via insulating material (CoPI) which
shall be additionally tested according to Annex B.
6.2 Standard conditions for testing
Unless otherwise specified in the relevant product standard, all tests shall be carried out under
standard conditions for testing as specified in IEC 60512-1.
The ambient temperature and the relative humidity at which the measurements are made shall
be stated in the test report.
In case of dispute about test results, the test shall be repeated at one of the test referred
conditions for referee measurements and tests set out in of IEC 60068-1.
6.3 Preconditioning
Where specified, the connections shall be preconditioned under standard conditions for testing
for a period of 24 h, in accordance with IEC 60512-1.
IEC 60352-7:2025 RLV © IEC 2025
6.4 Recovery
Where specified, the specimen shall be allowed to recover under standard conditions for testing
for a period of 1 h to 2 h after conditioning.
6.5 Mounting of specimen
a) When mounting is required in a test, the specimens shall be mounted using the normal
mounting method, unless otherwise specified in the relevant product standard.
b) Each test specimen shall consist of one spring clamp connection prepared as required in
the test schedules.
When more test specimens are required, they may be part of the same multipole spring
clamp connecting devices.
7 Tests
7.1 General examination
The examination shall be carried out in accordance with Test 1a of IEC 60512-1-1, and Test 1b
of IEC 60512-1-2. The visual examination test may be carried out with magnification up to
approximately five times.
All spring clamp terminations and wires shall be examined to ensure that the applicable
requirements of Clause 5 have been met.
7.2 Mechanical tests
7.2.1 Tensile strength
The test shall be carried out in accordance with Test 16t, method A, of IEC 60512-16-20.
Requirement:
The tensile strength of spring clamp connections shall be not less than specified in Table 1,
unless otherwise specified by the relevant product standard.
Table 1 – Values of tensile strength
Conductor cross-section Values of tensile strength
N minimum
mm
0,08 up to 0,22 (not included) 4
0,22 10
0,34 15
0,5 20
0,75 30
1,0 35
1,5 40
2,5 50
4,0 60
6,0 80
10,0 90
IEC 60352-7:2025 RLV © IEC 2025
7.2.2 Wire deflection
NOTE This test method is similar to the deflection test method for screwless terminals described in IEC 60884-1.
Spring clamp terminations shall be so designed that the inserted solid conductor remains
clamped, even when the conductor has been deflected during normal installation, for example,
during mounting in a box, and the deflecting stress is transferred to the spring clamp
termination.
Compliance is checked by the following test which is made on specimens which have not been
used for any other test.
a) Test apparatus
The test apparatus, the principle of which is shown in Figure 4, shall be so constructed that:
– a specified conductor, properly inserted into a terminal, is allowed to be deflected in any
of the 12 directions differing from each other by 30°, with a tolerance referred to each
direction of ±5° and;
– the starting point can be varied by 10° and 20° from the original point.
A reference direction need not be specified.
The deflection of the conductor from its straight position to the testing positions shall be
effected by means of a suitable device applying a specified force to the conductor at
a certain distance from the terminal.
The deflecting device shall be so designed that:
– the force is applied in the direction perpendicular to the undeflected conductor;
– the deflection is attained without rotation or displacement of the conductor within the
clamping unit, and
– the force remains applied whilst the prescribed voltage drop measurement is made.
Provisions shall be made so that the voltage drop across the spring clamp termination under
test can be measured when the conductor is connected, as shown for example
in Figure 3.Figure 3.
b) Test method
The specimen is mounted on the fixed part of the test apparatus in such a way that the
specified conductor inserted into the spring clamp termination under test can be freely
deflected.
The surface of the test conductor shall be free of detrimental contamination or corrosion.
NOTE If necessary, the inserted conductor can may be permanently bent around obstacles,
so that these do not influence the results of the test.
In some cases, with the exception of the case of guidance for the conductors, it may be
advisable to remove those parts of the specimen which do not allow the deflection of the
conductor corresponding to the force to be applied.
A spring clamp termination is fitted as for normal use with a solid copper conductor having
the smallest cross-sectional area as specified by the manufacturer and is submitted to a
first test sequence; the same spring clamp termination is submitted to a second test
sequence using the conductor having the largest cross-sectional area, unless the first test
sequence has failed.
The force for deflecting the conductor is specified in Table 2, the distance of 100 mm being
measured from the extremity of the terminal, including the guidance for the conductor, if
any, to the point of application of the force to the conductor.
The test is made with continuous current (i.e. the current is not switched on and off during
the test); a suitable power supply should be used so that the current variations are kept
within ±5 % during the test.
IEC 60352-7:2025 RLV © IEC 2025
Table 2 – Value of force for wire deflection test
Cross-section of the test conductor Force for deflecting the test
conductors
N
mm
0,5 up to 0,75 (not included) 0,09
0,75 0,16
1,0 0,25
1,5 0,5
2,5 1,0
4 2,0
6 3,5
10 7,0
The forces are chosen so that they stress the conductors close to the limit of
elasticity.
c) Test procedure
A tenth of the test current assigned to the wire according to Table 4 is passed through the
spring clamp connection under test. A force, according to Table 2, is applied to the test
conductor inserted in the spring clamp termination under test in the direction of one of the
12 directions shown in Figure 4 and the voltage drop across this spring clamp connection is
measured. The force is then removed.
The force is then applied successively in each of the remaining 11 directions shown in
Figure 4 following the same test procedure.
If at any of the 12 test directions the voltage drop is greater than 2,5 mV, the force is kept
applied in this direction until the voltage drop is reduced to a value below 2,5 mV, but for
not more than 1 min. After the voltage drop has reached a value lower than or equal to
2,5 mV, the force is kept applied in the same direction for a further period of 30 s during
which period the voltage drop shall not increase.
The other specimens of the set are tested following the same test procedure, but moving
the 12 directions of the force so that they differ by approximately 10° for each specimen. If
one specimen of the set has failed at one of the directions of application of the test force,
the tests are repeated on another set of specimens, all of which shall comply with the
repeated tests.
IEC 60352-7:2025 R
...