IEC 62873-3-1:2020

IEC 62873-3-1 ®
Edition 2.0 2020-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Residual current operated circuit-breakers for household and similar use –
Part 3-1: Particular requirements for RCDs devices with screwless-type
terminals for external copper conductors

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IEC 62873-3-1 ®
Edition 2.0 2020-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Residual current operated circuit-breakers for household and similar use –

Part 3-1: Particular requirements for RCDs devices with screwless-type

terminals for external copper conductors

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50 ISBN 978-2-8322-9114-6

– 2 – IEC 62873-3-1:2020 RLV © IEC 2020
CONTENTS
FOREWORD . 3
INTRODUCTION . 2
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Classification . 7
5 Characteristics of RCDs devices . 8
6 Marking and other product information . 8
7 Standard conditions for operation in service and for installation . 8
8 Requirements for construction and operation . 8
8.1 General . 8
8.2 Connection or and disconnection of conductors . 8
8.3 Dimensions of connectable conductors . 9
8.4 Connectable cross-sectional areas . 10
8.5 Insertion and withdrawal of conductors . 10
8.6 Design and construction of terminals . 10
8.7 Resistance to ageing . 11
9 Tests . 11
9.1 General . 11
9.2 Test of reliability of screwless-type terminals . 11
9.2.1 Reliability of screwless system . 11
9.2.2 Test of reliability of connection . 12
9.3 Tests of reliability of terminals for external conductors . 12
9.3.1 Mechanical strength. 12
9.3.2 Cycling test. 12
Bibliography . 16

Figure 1 – Connecting samples . 13
Figure 2 – Examples of screwless-type terminals . 15

Table 1 – Connectable conductors Conductors and their theoretical diameters . 9
Table 2 – Cross-sections of copper conductors connectable to screwless-type
terminals . 10
Table 3 – Pull forces . 12
Table 4 – Test copper conductors corresponding to the rated currents . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RESIDUAL CURRENT OPERATED CIRCUIT-BREAKERS
FOR HOUSEHOLD AND SIMILAR USE –

Part 3-1: Particular requirements for RCDs devices with
screwless-type terminals for external copper conductors

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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This redline version of the official IEC Standard allows the user to identify the changes
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has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – IEC 62873-3-1:2020 RLV © IEC 2020
International Standard IEC 62873-3-1 has been prepared by subcommittee 23E:
Circuit-breakers and similar equipment for household use, of IEC technical committee 23:
Electrical accessories.
This second edition cancels and replaces the first edition published in 2016. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Modification of scope to cover screwless-type terminals up to 40 A;
b) Modification of scope to address other devices in addition to RCDs;
c) Modification of Table 1 to cover rated currents up to 40 A;
d) Modification of 8.1 so that IEC 62873-3-1 can be referred to by other product standards in
addition to those for RCDs;
e) Modification of 9.1 so that IEC 62873-3-1 can be referred to by other product standards in
addition to those for RCDs.
The text of this International Standard is based on the following documents:
FDIS Report on voting
23E/1190/FDIS 23E/1200/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document is intended to be referred to by a product standard of subcommittee
IEC SC23E (e.g. from the IEC 61008 series, IEC 61009 series, IEC 62606, and IEC 63052).
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62873 series, published under the general title Residual current
operated circuit-breakers for household and similar use, 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
This document is part of the series described in the outline document IEC 62873-1.

– 6 – IEC 62873-3-1:2020 RLV © IEC 2020
RESIDUAL CURRENT OPERATED CIRCUIT-BREAKERS
FOR HOUSEHOLD AND SIMILAR USE –

Part 3-1: Particular requirements for RCDs devices with
screwless-type terminals for external copper conductors

1 Scope
This part of IEC 62873 applies to RCDs equipped with screwless terminals, for current not
exceeding 20 A primarily suitable for connecting unprepared (see 3.5) copper conductors of
cross-section up to 4 mm .
This part of IEC 62873 cannot be used alone but it is intended to be applied together with an
RCD product standard (IEC 61008-1 or IEC 61009-1) if an RCD is equipped with screwless
terminals.
NOTE In AT, CZ, DK, NL, NO, PO, PT and CH, the upper limit of current for use of screwless terminals is 16 A.
This document applies to devices equipped with screwless-type terminals for current not
exceeding 40 A, primarily suitable for connecting unprepared copper conductors of
cross-section up to 10 mm .
This document cannot be used alone but is intended to be applied together with the applicable
product standard in which it is referred to.
NOTE 1 In CZ, DK, NL, PO and CH, the upper limit of current for use of screwless-type terminals is 16 A.
NOTE 2 In JP, the upper limit of current for use of screwless-type terminals is 30 A.
NOTE 3 The manufacturer can declare in its documentation specific conditions permitting the use of prepared
conductors.
In this document, screwless-type terminals are referred to as terminals, and copper
conductors are referred to as conductors.
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 61008-1, Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs) – Part 1: General rules
IEC 61009-1, Residual current operated circuit-breakers with integral overcurrent protection
for household and similar uses (RCBOs) – Part 1: General rules
IEC 62873-2, Residual current operated circuit-breakers for household and similar use –
Part 2: Residual current devices (RCDs) – Vocabulary

3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62873-2 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• ISO Online browsing platform: available at http://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
3.1
clamping unit
part of the terminal necessary for mechanical clamping and electrical connection of the
conductors including parts necessary to ensure correct contact pressure
3.2
universal terminal
terminal for the connection and disconnection of all types of conductors (rigid and flexible)
Note 1 to entry: In the following countries, only universal screwless-type terminals are accepted: AT, BE, CN, DK,
DE, ES, FR, IT, PT, SE and CH.
3.3
non-universal terminal
terminal for the connection and disconnection of a certain kind of conductor only (e.g.
rigid-solid conductors only or rigid-[solid or stranded] conductors only)
3.4
push-wire terminal
non-universal terminal (see 3.3) in which the connection is made by pushing in rigid (solid or
stranded) conductors
3.5
unprepared conductor
conductor which has been cut and the insulation of which has been removed for insertion into
a terminal
Note 1 to entry: A conductor the shape of which is arranged for introduction into a terminal or the strands of which
are twisted to consolidate the end is considered as an unprepared conductor.
[SOURCE: IEC 60050-442:1998, 442-01-26]
3.6
low-current terminal
terminal intended to connect a conductor to a device capable of supplying a voltage signal
and/or a current not exceeding 300 mA to the device
Note 1 to entry: This does not apply to special terminal constructions intended to connect to flat or other multiwire
cables by performing one "clamping action" only for more than one wire (e.g. bus connections).
4 Classification
Clause 4 of the RCD product standard, in which this document is referred to, applies.

– 8 – IEC 62873-3-1:2020 RLV © IEC 2020
5 Characteristics of RCDs devices
Clause 5 of the RCD product standard, in which this document is referred to, applies.
6 Marking and other product information
In addition to Clause 6 of the RCD product standard, in which this document is referred to, the
following requirements markings apply:
Universal terminals:
– no marking.
Non-universal terminals:
– terminals declared for rigid-solid conductors shall be marked with the letters "sol";
– terminals declared for rigid (solid and stranded) conductors shall be marked with the letter
"r";
– terminals declared for flexible conductors shall be marked with the letter "f".
The markings shall appear on the device or, if the space available is not sufficient, on the
smallest package unit or in technical information.
An appropriate marking indicating the length of insulation to be removed before insertion of
the conductor into the terminal shall be shown on the RCD product.
The manufacturer shall also provide information, in its literature, on the maximum number of
conductors which may be clamped.
7 Standard conditions for operation in service and for installation
Clause 7 of the RCD product standard, in which this document is referred to, applies.
8 Requirements for construction and operation
8.1 General
Clause 8 of the RCD product standard applies, with the following exceptions:
In 8.1.5, only 8.1.5.1, 8.1.5.2, 8.1.5.3, 8.1.5.6 and 8.1.5.7 apply.
Compliance is checked by inspection and by the tests of 9.2 and 9.3 of this standard.
In addition, the following requirements apply.
The requirements of Clause 8 of this document apply in addition to Clause 8 of the product
standard, in which this document is referred to.
Compliance is checked by inspection and by the tests of 9.2 and 9.3 of this document.
For low-current terminals, no significant current flow is expected in normal service. Therefore,
the tests of 9.3.2 are not performed.

8.2 Connection or and disconnection of conductors
The connection or and disconnection of conductors shall be made:
– by the use of a general-purpose tool or by a convenient device integral with the terminal to
open it and to assist the insertion or the withdrawal of the conductors (e.g. for universal
terminals);
or, for rigid conductors:
– by simple insertion. For the disconnection of the conductors, an operation other than a pull
on the conductor shall be necessary (e.g. for push-wire terminals).
Universal terminals shall accept rigid (solid or stranded) and flexible unprepared conductors.
They may also accept prepared conductors according to the manufacturer's declaration.
Non-universal terminals shall accept the types of conductors declared by the manufacturer.
Compliance is checked by inspection and by the tests of 9.2 and 9.3 of this document.
8.3 Dimensions of connectable conductors
The dimensions of connectable conductors are given in Table 1.
The ability to connect these conductors shall be checked by inspection and by the tests of 9.2
and 9.3 of this document.
Table 1 – Connectable conductors Conductors and their theoretical diameters
Connectable conductors and their theoretical diameter
Metric AWG
Rigid Flexible Rigid Flexible
Classes
Class B
a
Solid Stranded  Solid I, K, M,
a
stranded
b
stranded
2 2
mm ∅ mm ∅ mm mm ∅ mm gauge ∅ mm ∅ mm gauge ∅ mm
1,0 1,2 1,4 1,0 1,5 18 1,02 1,16 18 1,28
1,5 1,5 1,7 1,5 1,8 16 1,29 1,46 16 1,60
2,5 1,9 2,2 2,5 2,3 14 1,63 1,84 14 2,08
4,0 2,4 2,7 4,0 2,9 12 2,05 2,32 12 2,70
NOTE Diameters of the largest rigid and flexible conductors are based on IEC 60228, and, for AWG conductors,
on ASTM B 172-01a.
a
Nominal diameter + 5 %.
b
Largest diameter + 5 % for any of the three classes I, K and M.

– 10 – IEC 62873-3-1:2020 RLV © IEC 2020

Metric AWG
Rigid Flexible Rigid Flexible
Classes I,
Class B
a
K, M,
Solid Stranded  Solid
a
stranded
b
stranded
2 2
mm ∅ mm ∅ mm mm ∅ mm gauge ∅ mm ∅ mm gauge ∅ mm
1,0 1,2 1,4 1,0 1,5 18 1,07 1,23 18 1,28
1,5 1,5 1,7 1,5 1,8 16 1,35 1,55 16 1,60
2,5 1,9 2,2 2,5 2,4 14 1,71 1,95 14 2,08
4,0 2,4 2,7 4,0 3,0 12 2,15 2,45 12 2,70
6,0 2,9 3,3 6,0 3,9 10 2,72 3,09 10 3,36
10,0 3,7 4,2 10,0 5,1 8 3,43 3,89 8 4,32
NOTE Diameters of the largest rigid and flexible conductors are based on Table C.1 of IEC 60228:2004, and, for
AWG conductors, on ASTM B 172-17.
a
Nominal diameter + 5 %.
b
Largest diameter + 5 % for any of the three classes I, K and M.

8.4 Connectable cross-sectional areas
The nominal cross-sections to be clamped are defined in Table 2.
Table 2 – Cross-sections of copper conductors
connectable to screwless-type terminals
Rated current Nominal cross-sections to be clamped
A mm
Low-current terminals To be declared by the manufacturer
Up to and including 13 1 up to and including 2,5
Above 13 up to and including 20 1,5 up to and including 4
a
Above 20 up to and including 25 1,5 up to and including 6
a
Above 25 up to and including 32 2,5 up to and including 6
Above 32 up to and including 40 4 up to and including 10
a 2
For terminals with two connections per pole, the maximum value is 4 mm . Two conductors in parallel (also
known as ring circuits) are used in some countries.

Compliance is checked by inspection and by the tests of 9.2 and 9.3 of this document.
8.5 Insertion and disconnection withdrawal of conductors
The insertion and disconnection withdrawal of the conductors shall be made carried out in
accordance with the manufacturer's instructions.
Compliance is checked by inspection.
8.6 Design and construction of terminals
Terminals shall be so designed and constructed that:
– each conductor is clamped individually;

– during the operation of connection or disconnection the conductors can be connected or
disconnected either at the same time or separately;
– inadequate insertion of the conductor is avoided.
It shall be possible to clamp securely any number of conductors up to the maximum provided
for.
Compliance is checked by inspection and by the tests of 9.2 and 9.3 of this document.
NOTE Examples are given in Figure 2.
8.7 Resistance to ageing
The terminals shall be resistant to ageing.
Compliance is checked by the test of 9.3.2.
9 Tests
9.1 General
Clause 9 of the RCD product standard applies, with the exception of 9.4 and 9.5.
The requirements of Clause 9 of this document apply in addition to Clause 9 of the product
standard, in which this document is referred to.
Test of reliability of screws, current-carrying parts and connections, and the test of reliability
of screw-type terminals for external copper conductors of Clause 9 of the product standard
are replaced here by 9.2 and 9.3.
For short-circuit tests, the device shall be connected with cables having the maximum
cross-section according to Table 2 of this document.
9.2 Test of reliability of screwless-type terminals
9.2.1 Reliability of screwless system
The test is carried out on three terminals of poles of new samples, with copper conductors of
the rated cross-sectional area in accordance with Table 2. The types of conductors shall be in
accordance with 8.2 Table 1, as applicable.
The connection and subsequent disconnection shall be made carried out five times with the
smallest diameter conductor, and then successively five times with the largest diameter
conductor.
New conductors shall be used each time, except for the fifth time, when the conductor used
for the fourth insertion is clamped at the same place. Before insertion into the terminal, wires
of stranded rigid conductors shall be re-shaped and wires of flexible conductors shall be
twisted to consolidate the ends.
For each insertion, the conductors are shall either be pushed as far as possible into the
terminal or shall be inserted so that adequate connection is obvious.
After each insertion, the conductor being inserted is rotated 90° along its axis at the level of
the clamped section and subsequently disconnected.
After these tests, the terminal shall not be damaged in such a way as to impair its further use.

– 12 – IEC 62873-3-1:2020 RLV © IEC 2020
9.2.2 Test of reliability of connection
Three terminals of poles of new samples are fitted with new copper conductors of the type
and of the rated cross-sectional area according to Table 2.
The types of conductors shall be in accordance with 8.2 Table 1, as applicable.
Before insertion into the terminal, wires of stranded rigid conductors and flexible conductors
shall be re-shaped and wires of flexible conductors shall be twisted to consolidate the ends.
It shall be possible to fit the conductor into the terminal without undue force in the case of
universal terminals and with the force necessary by hand in the case of push-wire terminals.
The conductor is shall either be pushed as far as possible into the terminal or shall be
inserted so that adequate connection is obvious.
After the test, no wire of the conductor shall have escaped outside the terminal.
9.3 Tests of reliability of terminals for external conductors
9.3.1 Mechanical strength
For the pull-out test, three terminals of poles of new samples are fitted with new conductors of
the type and of the minimum and maximum cross-sectional areas according to Table 2.
Before insertion into the terminal, wires of stranded rigid conductors and flexible conductors
shall be re-shaped and wires of flexible conductors shall be twisted to consolidate the ends.
Each conductor is then subjected to a pull force of the value shown in Table 3. The pull is
applied without jerks for 1 min in the direction of the axis of the conductor.
Table 3 – Pull forces
Cross-sectional area Pull force
mm N
1,0 35
1,5 40
2,5 50
4,0 60
6,0 80
10,0 90
During the test, the conductor shall not slip out of the terminal.
9.3.2 Cycling test
The test is made with new copper conductors having cross section according to Table 10 of
the RCD product standard.
NOTE 1 Tables 6, 10, 11 (in IEC 61008-1:2010) and Tables 8, 13, 14 (in IEC 61009-1:2010) have been
replaced by the harmonized new numbers: 9, 10, 11.
The test is made with new copper conductors having cross section according to Table 4.

Table 4 – Test copper conductors corresponding to the rated currents
Rated current 6 13 20 25 32
I I ≤ < I ≤ < I ≤ < I ≤ < I ≤ < I ≤
n n n n n n n
A 6 13 20 25 32 40
S
a
1 1,5 2,5 4 6 10
mm
a
For terminals with two connections per pole, the maximum value is 4 mm². Two conductors in parallel (also
known as ring circuits) are used in some countries.

The test is carried out on new samples (a sample is one pole), the number of which is defined
below, according to the type of terminals:
– universal terminals for rigid (solid and stranded) and flexible conductors: three samples
each (six samples in total);
NOTE 2 In case of rigid conductors, solid conductors are used (if solid conductors are not available in a
given country, stranded conductors can be used).
– non-universal terminals for solid conductors only: three samples;
– non-universal for rigid (solid and stranded) conductors: three samples each (six samples);
– non-universal for flexible conductors only: three samples.
A conductor having the cross section defined in Table 10 of the RCD product standard is
connected in series as in normal use to each of the three samples as defined in Figure 1.
The conductor of 1 m is connected in series between two terminals to be tested as shown in
Figure 1.
Figure 1 – Connecting samples
The sample is provided with a hole (or equivalent) in order to measure the voltage drop on the
terminal.
The whole test arrangement, including the conductors, is placed in a heating cabinet which is
initially kept at a temperature of (20 ± 2) °C.
To avoid any movement of the test arrangement until all the following voltage drop tests have
been completed, the poles should be fixed on a common support.
Except during the cooling period, a test current corresponding to the rated current of the
circuit breaker is applied to the circuit.

– 14 – IEC 62873-3-1:2020 RLV © IEC 2020
The samples shall then be subjected to 192 temperature cycles, each cycle having a duration
of approximately 1 h, as follows:
The air temperature in the cabinet is raised to 40 °C in approximately 20 min. It is maintained
within ±5 °C of this value for approximately 10 min.
The samples are then allowed to cool down in for approximately 20 min to a temperature of
approximately 30 °C, forced cooling being allowed. They are kept at this temperature for
approximately 10 min and, if necessary for measuring the voltage drop, allowed to cool down
further, to a temperature of (20 ± 2) °C.
nd
The maximum voltage drop, measured at each terminal, at the end of the 192 cycle, with

the rated current shall not exceed the smaller of the two following values:
– either 22,5 mV or
– 1,5 times the value measured after th
...