EN 60947-4-2:2000/A2:2006

SLOVENSKI STANDARD
01-september-2007
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Low-voltage switchgear and controlgear -- Part 4-2: Contactors and motor-starters - AC
semiconductor motor controllers and starters (IEC 60947-4-2:1999/A2:2006)
Niederspannungsschaltgeräte -- Teil 4-2: Schütze und Motorstarter - Halbleiter-Motor-
Steuergeräte und -Starter für Wechselspannungen (IEC 60947-4-2:1999/A2:2006)
Appareillage a basse tension -- Partie 4-2: Contacteurs et démarreurs de moteurs -
Gradateurs et démarreurs a semiconducteurs de moteurs a courant alternatif (IEC 60947
-4-2:1999/A2:2006)
Ta slovenski standard je istoveten z: EN 60947-4-2:2000/A2:2006
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60947-4-2/A2
NORME EUROPÉENNE
December 2006
EUROPÄISCHE NORM
ICS 29.130.20
English version
Low-voltage switchgear and controlgear
Part 4-2: Contactors and motor-starters
AC semiconductor motor controllers and starters
(IEC 60947-4-2:1999/A2:2006)
Appareillage à basse tension  Niederspannungsschaltgeräte
Partie 4-2: Contacteurs Teil 4-2: Schütze und Motorstarter -
et démarreurs de moteurs - Halbleiter-Motor-Steuergeräte
Gradateurs et démarreurs und -Starter für Wechselspannungen
à semiconducteurs de moteurs (IEC 60947-4-2:1999/A2:2006)
à courant alternatif
(CEI 60947-4-2:1999/A2:2006)
This amendment A2 modifies the European Standard EN 60947-4-2:2000; it was approved by CENELEC on
2006-12-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this amendment 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 amendment 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, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the 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

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60947-4-2:2000/A2:2006 E

Foreword
The text of document 17B/1499/FDIS, future amendment 2 to IEC 60947-4-2:1999, prepared by SC 17B,
Low-voltage switchgear and controlgear, of IEC TC 17, Switchgear and controlgear, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as amendment A2 to EN 60947-4-2:2000
on 2006-12-01.
The following dates were fixed:
– latest date by which the amendment has to be
implemented at national level by publication of
an identical national standard or by endorsement (dop) 2007-09-01
– latest date by which the national standards conflicting
with the amendment have to be withdrawn (dow) 2009-12-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of amendment 2:2006 to the International Standard IEC 60947-4-2:1999 was approved by
CENELEC as an amendment to the European Standard without any modification.
__________
- 3 - EN 60947-4-2:2000/A2:2006
Replace Annex ZA of EN 60947-4-2:2000 by:
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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60034-1 2004 Rotating electrical machines EN 60034-1 2004
Part 1: Rating and performance

IEC 60050-161 1990 International Electrotechnical Vocabulary - -
A1 1997 (IEV) - -
A2 1998 Chapter 161: Electromagnetic compatibility - -

IEC 60085 2004 Electrical insulation - Thermal classification EN 60085 2004

IEC 60146 Series Semiconductor convertors - General EN 60146 Series
requirements and line commutated convertors

IEC 60269-1 1998 Low-voltage fuses EN 60269-1 1998
A1 2005 Part 1: General requirements A1 2005

IEC 60410 1973 Sampling plans and procedures for inspection - -
by attributes
IEC 60439-1 1999 Low-voltage switchgear and controlgear EN 60439-1 1999
A1 2004 assemblies A1 2004
Part 1: Type-tested and partially type-tested
assemblies
IEC 60664 Series Insulation coordination for equipment within EN 60664 Series
low-voltage systems
IEC 60947-1 2004 Low-voltage switchgear and controlgear EN 60947-1 2004
Part 1: General rules + corr. November 2004

IEC/TR 61000-2-1 1990 Electromagnetic compatibility (EMC) - -
Part 2: Environment - Section 1: Description
of the environment - Electromagnetic
environment for low-frequency conducted
disturbances and signalling in public power
supply systems
IEC 61000-3-2 2005 Electromagnetic compatibility (EMC) EN 61000-3-2 2006
Part 3-2: Limits - Limits for harmonic current
emissions (equipment input current <= 16 A
per phase)
IEC 61000-4-2 1995 Electromagnetic compatibility (EMC) EN 61000-4-2 1995
A1 1998 Part 4-2: Testing and measurement A1 1998
A2 2000 techniques - Electrostatic discharge A2 2001
immunity test
Publication Year Title EN/HD Year
IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) EN 61000-4-3 2006
Part 4-3 : Testing and measurement
techniques - Radiated, radio-frequency,
electromagnetic field immunity test

1)
IEC 61000-4-4 1995 Electromagnetic compatibility (EMC) EN 61000-4-4 1995
A1 2000 Part 4-4: Testing and measurement A1 2001

A2 2001 techniques - Electrical fast transient/burst A2 2001
immunity test
2)
IEC 61000-4-5 1995 Electromagnetic compatibility (EMC) EN 61000-4-5) 1995

A1 2000 Part 4-5: Testing and measurement A1 2001
techniques - Surge immunity test

IEC 61000-4-6 2003 Electromagnetic compatibility (EMC) - -
A1 2004 Part 4-6: Testing and measurement
techniques - Immunity to conducted
disturbances, induced by radio-frequency
fields
3)
IEC 61000-4-11 1994 Electromagnetic compatibility (EMC) EN 61000-4-11 1994
A1 2000 Part 4-11: Testing and measurement A1 2001
techniques - Voltage dips, short interruptions
and voltage variations immunity tests

IEC 61131-2 2003 Programmable controllers EN 61131-2 2003
Part 2: Equipment requirements and tests + corr. August 2003

CISPR 11 (mod) 2003 Industrial scientific and medical (ISM) radio-
4)
A1 (mod) 2004 frequency equipment - Electromagnetic EN 55011 200X
disturbance characteristics - Limits and
methods of measurement
5) 4)
CISPR 14-1 - Electromagnetic compatibility - EN 55014-1 200X
Requirements for household appliances,
electric tools and similar apparatus
Part 1: Emission
1)
EN 61000-4-4 is superseded by EN 61000-4-4:2004, which is based on IEC 61000-4-4:2004.
2)
EN 61000-4-5 is superseded by EN 61000-4-5:2006, which is based on IEC 61000-4-5:2005.
3)
EN 61000-4-11 is superseded by EN 61000-4-11:2004, which is based on IEC 61000-4-11:2004.
4)
To be published.
5)
Undated reference.
NORME CEI
INTERNATIONALE
IEC
60947-4-2
INTERNATIONAL
STANDARD
AMENDEMENT 2
AMENDMENT 2
2006-11
Amendement 2
Appareillage à basse tension –
Partie 4-2:
Contacteurs et démarreurs de moteurs –
Gradateurs et démarreurs à semiconducteurs
de moteurs à courant alternatif

Amendment 2
Low-voltage switchgear and controlgear –
Part 4-2:
Contactors and motor-starters –
AC semiconductor motor controllers and starters
© IEC 2006 Droits de reproduction réservés ⎯ Copyright - all rights reserved
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
V
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

60947-4-2 Amend. 2 © IEC:2006 – 3 –
FOREWORD
This amendment has been prepared by subcommittee 17B: Low-voltage switchgear and
controlgear, of IEC technical committee 17: Switchgear and controlgear.
The text of this amendment is based on the following documents:
FDIS Report on voting
17B/1499/FDIS 17B/1524/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base 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.
________________
Page 3
CONTENTS
Modify the title of Clause 3 to read:
3 Definitions, symbols and abbreviations
Insert the following:
3.3 Symbols and abbreviations
Delete Subclause 5.9.
Delete Subclause 9.4.
Replace the title of Annexes B and C by the following:
Annex B Vacant
Annex C (normative) Co-ordination at the crossover current between the starter and
associated SCPD
Insert the title of Annex K:
Annex K (normative) Extended functions within electronic overload relays
Insert the following:
Figure 3 – Thermal memory test

60947-4-2 Amend. 2 © IEC:2006 – 5 –
Figure 4 – Multiple of current setting limits for ambient air temperature compensated time-
delay overload relays
Figure C.1 – Examples of time-current withstand characteristic
Figure K.1 – Test circuit for the verification of the operating characteristic of a residual current
electronic overload relay
Replace the title of Table 4 by the following:
Table 4 – Minimum overload current withstand time (T ) in relation to overload current ratio
x
(X) and corresponding to overload relay trip class (see Table 19)
Insert the following:
Table 19 – Trip classes of overload relays
Table 20 – Limits of operation of time-delay overload relays when energized on all poles
Table 21 – Limits of operation of three-pole time-delay overload relays when energized on two
poles only
Delete Tables B.1, B.2 and B.3.
Insert the following:
Table C.1 – Test conditions
Table K.1 – Operating time of residual current electronic overload relays

Page 13
1 Scope and object
Modify the existing text of the sixth paragraph to read:
“Contactors, overload relays and control circuit devices used in controllers and starters … “

Page 15 and amendment 1, page 5
2 Normative references
Replace the existing text of first paragraph by the following:
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.

60947-4-2 Amend. 2 © IEC:2006 – 7 –
Replace the reference to IEC 60034-1:1996 by the following:
IEC 60034-1:2004, Rotating electrical machines – Part 1: Rating and performance
Add, after IEC 60050(161), the following references:
Amendment 1 (1997)
Amendment 2 (1998)
Replace the reference to IEC 60085:1984 by the following:
IEC 60085:2004, Electrical insulation – Thermal classification
Insert the following new reference:
IEC 60146 (all parts), Semiconductor convertors
Add, after IEC 60269-1, the following reference:
Amendment 1 (2005)
Replace the reference to IEC 60439-1:1992 by the following:
IEC 60439-1:1999, Low-voltage switchgear and controlgear assemblies – Part 1: Type-tested
and partially type-tested assemblies
Amendment 1 (2004)
Replace the reference to IEC 60947-1:1999 by the following:
IEC 60947-1:2004, Low-voltage switchgear and controlgear – Part 1: General rules
Replace the reference to IEC 61000-3-2:1995 by the following:
IEC 61000-3-2:2005, Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for
harmonic current emissions (equipment input current ≤16 A per phase)
Add, after IEC 61000-4-2, the following references:
Amendment 1 (1998)
Amendment 2 (2000)
Replace the reference to IEC 61000-4-3:1995 by the following:
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated radio-frequency electromagnetic field immunity test
Add, after IEC 61000-4-4, the following references:
Amendment 1 (2000)
Amendment 2 (2001)
60947-4-2 Amend. 2 © IEC:2006 – 9 –
Add, after IEC 61000-4-5, the following reference:
Amendment 1 (2000)
Replace the reference to IEC 61000-4-6:1996 by the following:
IEC 61000-4-6:2003, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
Amendment 1 (2004)
Add, after IEC 61000-4-11, the following reference:
Amendment 1 (2000)
Insert the following new reference:
IEC 61131-2:2003, Programmable controllers – Part 2: Equipment requirements and tests
Replace the reference to CISPR 11:1997 by the following:
CISPR 11:2003, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic disturbance characteristics – Limits and methods of measurement
Amendment 1 (2004)
Replace the reference to CISPR 14-1:1993 by the following:
CISPR 14-1, Electromagnetic compatibility – Requirements for household appliances, electric
tools and similar apparatus – Part 1: Emission
Delete the reference to CISPR 14-2:1993.

Page 17 and Amendment 1, page 5
3 Definitions
Replace the existing title by the following:
3 Definitions, symbols and abbreviations
Insert, after the first paragraph the following alphabetical index of definitions:
Reference
A
AC semiconductor motor controller . 3.1.1.1

B
Burst (of pulses or oscillations) . 3.2.7
Bypassed controller . 3.1.29

60947-4-2 Amend. 2 © IEC:2006 – 11 –
C
CO operation . 3.1.30
Controlled acceleration . 3.1.5
Controlled deceleration. 3.1.6
Controlled running. 3.1.7
Current-limit function . 3.1.3

E
Electromagnetic compatibility, EMC (abbreviation). 3.2.1
Electromagnetic disturbance . 3.2.3
Electromagnetic emission . 3.2.2

F
Full-on (state of controllers) . 3.1.10

H
Hybrid motor controllers or starters, form HxA (where x = 1, 2 or 3) . 3.1.2.1
Hybrid motor controllers or starters, form HxB . 3.1.2.2

I
Inhibit time. 3.1.26

J
Jam sensitive electronic overload relay. 3.1.25

M
Manoeuvre. 3.1.4
Minimum load current . 3.1.11

O
O operation. 3.1.31
OFF-state leakage current . 3.1.13
OFF-time. 3.1.28
ON-state. 3.1.9
ON-time. 3.1.27
Open position . 3.1.2.3
Operating capability. 3.1.16
Operating cycle (of a controller). 3.1.15
Operation (of a controller). 3.1.14
Overload current profile . 3.1.17

P
Phase loss sensitive overload relay or release. 3.1.21
Prospective locked rotor current . 3.1.8

R
Radio (frequency) disturbance . 3.2.4
Radio frequency interference, RFI (abbreviation) . 3.2.5
Rating index . 3.1.18

S
Semiconductor direct-on-line (DOL) motor controller (form 3) . 3.1.1.1.3
Semiconductor motor controller (form 1) . 3.1.1.1.1
Semiconductor motor starter (form 1, form 2, form 3). 3.1.1.2
Semiconductor soft-start motor controller (form 2). 3.1.1.1.2
Stall sensitive electronic overload relay . 3.1.24

60947-4-2 Amend. 2 © IEC:2006 – 13 –
T
Transient (adjective and noun). 3.2.6
Trip-free controller or starter . 3.1.20
Tripping operation (of a controller or starter). 3.1.19

U
Under-current relay or release . 3.1.22
Under-voltage relay or release. 3.1.23

V
Voltage surge . 3.2.8

3.1.1.1
Number the existing note as NOTE 1.
Add the following new NOTE 2:
NOTE 2 In a circuit where the current passes through zero (alternately or otherwise), the effect of "not making" the
current following such a zero value is equivalent to breaking the current.

Page 19
3.1.1.2
Correction in the French text only.

Page 21 and Amendment 1, page 7
Figure 1 – Semiconductor motor control devices
In row “Bypassed hybrid motor controller”:
c
- modify the title to read “Bypassed hybrid motor controller ”;
- delete the reference “(see 8.2.4.2.3)”.
c
Add, at the bottom of the figure, the following new footnote “ ”:
c
For other configurations, tests may be suitably adapted by agreement between the user and the manufacturer.

Page 23
3.1.2.1
Correction in the French text only.

Page 27
3.1.19
Correction in the French text only.

60947-4-2 Amend. 2 © IEC:2006 – 15 –
Page 29
3.1.20
Correction on the French text only.

Page 29 and Amendment 1, page 7
Modify definition 3.1.21 as follows:
3.1.21
phase loss sensitive overload relay or release
multipole overload relay or release which operates in case of overload and also in case of
loss of phase in accordance with specified requirements
Insert, after definition 3.1.21, the following new definitions 3.1.22 to 3.1.26:
3.1.22
under-current relay or release
measuring relay or release which operates automatically when the current through it is
reduced below a predetermined value
3.1.23
under-voltage relay or release
measuring relay or release which operates automatically when the voltage applied to it is
reduced below a predetermined value
3.1.24
stall sensitive electronic overload relay
electronic overload relay which operates when the current has not decreased below a
predetermined value for a specific period of time during start-up or when the relay receives
the input indicating there is no rotation of the motor after a predetermined time in accordance
with specified requirements
NOTE Explanation of stall: rotor locked during start.
3.1.25
jam sensitive electronic overload relay
electronic overload relay which operates in the case of overload and also when the current
has increased above a predetermined value for a specific period of time during run in
accordance with specified requirements
NOTE Explanation of jam: high overload occurring after the completion of starting which causes the current to
reach the locked rotor current value of the motor being controlled.
3.1.26
inhibit time
time-delay period during which the tripping function of the relay is inhibited (may be
adjustable)
Renumber definitions 3.1.22 to 3.1.24 as 3.1.27 to 3.1.29 respectively.
Add, after definition 3.1.29, the following new definitions 3.1.30 and 3.1.31:

60947-4-2 Amend. 2 © IEC:2006 – 17 –
3.1.30
CO operation
breaking of the circuit by the SCPD resulting from closing the circuit by the equipment under
test
3.1.31
O operation
breaking of the circuit by the SCPD resulting from closing the circuit on the equipment under
test which is in the closed position

Page 31
Modify the existing text of the note of definition 3.2.5 to read:
“… applied to a radio-frequency disturbance or an unwanted signal.”
Add, after definition 3.2.8, the following new subclause:
3.3 Symbols and abbreviations
A Final ambient temperature (9.3.3.3.4)
f
C Final case temperature (9.3.3.3.4)
f
EMC Electromagnetic compatibility
EUT Equipment under test
I Current made and broken (Table 8)
c
I Rated operational current (5.3.2.3)
e
I Leakage current after the blocking and commutating capability test (9.3.3.6.3)
F
I Initial test current (9.3.3.6.2)
init
I OFF-state leakage current (3.1.13)
L
I Prospective locked rotor current (3.1.8)
LRP
I Leakage current before the blocking and commutating capability test (9.3.3.6.3)
O
I Conventional free air thermal current (5.3.2.1)
th
I Conventional enclosed thermal current (5.3.2.2)
the
I Rated uninterrupted current (5.3.2.4)
u
SCPD Short-circuit protective device
U Rated control circuit voltage (5.5)
c
U Rated operational voltage (5.3.1.1)
e
U Rated insulation voltage (5.3.1.2)
i
U Rated impulse withstand voltage (5.3.1.3)
imp
U Power frequency recovery voltage (Table 6)
r
U Rated control supply voltage (5.5)
s
5.1 Summary of characteristics
Delete the last dashed item “switching overvoltages (5.9)”.

60947-4-2 Amend. 2 © IEC:2006 – 19 –
Page 41
5.3.5.1 Overload current profile
Replace the existing text of the last paragraph by the following:
For a starter, T is the minimum operating time allowed by the tolerances of the overload
x
relay.
Page 45
5.4 Utilization category
Replace the first sentence of the fourth paragraph by the following:
The first digit of the utilization category identification designates a semiconductor switching
device (e.g. within this standard a semiconductor motor controller or starter).

Page 47 and Amendment 1, page 9
Table 2 – Utilization categories
Replace note 1 by the following:
NOTE 1 The means of bypassing the semiconductor controller or starter may be integral with the controller/starter
or installed separately. It also may be dependant or unrestricted as specified in 8.2.1.7 and 8.2.1.8.

Page 49
5.6 Auxiliary circuits
Add, at the end of this subclause, the following new paragraph:
Digital inputs and/or digital outputs contained in controllers and starters, and intended to be
compatible with PLC’s shall fulfil the requirements of IEC 61131-2.
5.7 Characteristics of relays and releases (overload relays)
Replace the existing text of this subclause by the following:
NOTE In the remainder of this standard, the words "overload relay" will be taken to apply equally to an overload
relay or an overload release, as appropriate.
5.7.1 Summary of characteristics
The characteristics of relays and releases shall be stated in the following terms, whenever
applicable:
60947-4-2 Amend. 2 © IEC:2006 – 21 –
– types of relay or release (see 5.7.2);
– characteristic values (see 5.7.3);
– designation and current settings of overload relays (see 5.7.4);
– time-current characteristics of overload relays (see 5.7.5);
– influence of ambient air temperature (see 5.7.6).
5.7.2 Types of relay or release
a) Under-voltage and under-current opening relay or release.
b) Overload time-delay relay the time-lag of which is:
1) dependent on previous load (e.g. thermal or electronic overload relay);
2) dependent on previous load (e.g. thermal or electronic overload relay) and also
sensitive to phase loss (see 3.1.21);
3) independent of previous load (without thermal memory).
c) Instantaneous over-current relay or release (e.g. jam sensitive, see 3.1.25).
d) Other relays or releases (e.g. control relay associated with devices for the thermal
protection of the starter).
e) Stall relay or release.
5.7.3 Characteristic values
a) Release with shunt coil, under-voltage (under-current), over-voltage (instantaneous over
current), current or voltage asymmetry and phase reversal opening relay or release:
− rated voltage (current);
− rated frequency;
− operating voltage (current);
− operating time (when applicable);
− inhibit time (when applicable).
b) Overload relay:
– designation and current settings (see 5.7.4);
– rated frequency, when necessary (for example in the case of a current transformer
operated overload relay);
– time-current characteristics (or range of characteristics), when necessary;
– trip class according to classification in Table 19, or the value of the maximum tripping
time, in seconds, under the conditions specified in 8.2.1.5.1.1.1 and Table 20,
column D, when this time exceeds 30 s;
– number of poles;
– nature of the relay: thermal, electronic or electronic without thermal memory;
– nature of the reset: manual or automatic.
c) Release with residual current sensing relay:
− rated current;
− operating current;
− operating time or time-current characteristic according to Table K.1;

60947-4-2 Amend. 2 © IEC:2006 – 23 –
− inhibit time (when applicable);
− type designation (see Annex K).
Table 19 – Trip classes of overload relays
Trip class Tripping time T under the conditions Tripping time T under the conditions
p p
specified in 8.2.1.5.1.1.1 and specified in 8.2.1.5.1.1.1 and
a
Table 20, column D Table 20, column D for tighter
a
tolerances (tolerance band E)
s s
2 − T ≤ 2
p
3 − 2 < T ≤ 3
p
5 0,5 < T ≤ 5 3 < T ≤ 5
p p
10A 2 < T ≤ 10 −
p
10 4 < T ≤ 10 5 < T ≤ 10
p p
20 6 < T ≤ 20 10 < T ≤ 20
p p
30 9 < T ≤ 30 20 < T ≤ 30
p p
40 30 < T ≤ 40
−
p
a
The manufacturer shall add the letter E to trip classes to indicate compliance with the band E.
NOTE 1 Depending on the nature of the relay, the tripping conditions are given in 8.2.1.5.
NOTE 2 The lower limiting values of T are selected to allow for differing heater characteristics and
p
manufacturing tolerances.
5.7.4 Designation and current settings of overload relays
Overload relays are designated by their current setting (or the upper and lower limits of the
current setting range, if adjustable) and their trip class.
The current setting (or current setting range) shall be marked on the relays.
However, if the current setting is influenced by the conditions of use or other factors which
cannot readily be marked on the relay, then the relay or any interchangeable parts thereof
(e.g. heaters, operating coils or current transformers) shall carry a number or an identifying
mark which makes it possible to obtain the relevant information from the manufacturer or his
catalogue or, preferably, from data furnished with the starter.
In the case of current transformer operated overload relays, the marking may refer either to
the primary current of the current transformer through which they are supplied or to the
current setting of the overload relays. In either case, the ratio of the current transformer shall
be stated.
5.7.5 Time-current characteristics of overload relays
Typical time-current characteristics shall be given in the form of curves supplied by the
manufacturer. These curves shall indicate how the tripping time, starting from the cold state
(see 5.7.6), varies with the current up to a value of at least maximum (X⋅ Ie) value. The
manufacturer shall be prepared to indicate, by suitable means, the general tolerances
applicable to these curves and the conductor cross-sections used for establishing these
curves (see 9.3.3.6.5, item c)).

60947-4-2 Amend. 2 © IEC:2006 – 25 –
NOTE It is recommended that the current be plotted as abscissae and the time as ordinates, using logarithmic
scales. It is recommended that the current be plotted as multiples of the setting current and the time in seconds on
the standard graph sheet detailed in IEC 60269-1.
5.7.6 Influence of ambient air temperature
The time-current characteristics (see 5.7.5) refer to a stated value of ambient air temperature,
and are based on no previous loading of the overload relay (viz. from an initial cold state).
This value of the ambient air temperature shall be clearly given on the time curves; the
preferred values are +20 °C or +40 °C.
The overload relays shall be able to operate within the ambient air temperature range of 0 °C
to +40 °C, and the manufacturer shall be prepared to state the effect of variation in ambient
air temperature on the characteristics of overload relays.
5.9 Switching overvoltages
Delete the title and the text of this subclause.
6.1 Nature of information
Modify the existing text of item e) to read:
“…, overload current profile (5.3.5.1), and duty cycle (5.3.4.6) or OFF-time, comprising …”
Delete, on page 51, the existing item p).
Rename items q) and r) as items p) and q).
Replace the existing item s) by the following two items:
r) characteristics according to 5.7.2, 5.7.5 and 5.7.6;
s) characteristics according to 5.7.3 and 5.7.4.

Page 51
6.2 Marking
Replace the existing text of the second and third paragraphs by the following:
Data under d) to u) in 6.1 shall be included on the nameplate, or on the equipment, or in the
manufacturer's published literature.
Data under items c), l) and s) in 6.1 shall preferably be marked on the equipment.
Add, at the end of this subclause, the following new paragraph:
If the manufacturer declares an electronic overload relay without thermal memory, this shall
be marked on the device.
60947-4-2 Amend. 2 © IEC:2006 – 27 –
Page 53
6.3 Instructions for installation, operation and maintenance
Replace the existing text of this subclause by the following:
Subclause 5.3 of IEC 60947-1 applies, with the following addition.
For products complying with this standard, the following are specific items to be considered:
− in the event of a short-circuit;
− in case of switching devices in bypassed controllers suitable only for restricted use (see
8.2.1.9);
− in the event of temperature rise above 50 K of the metallic radiator surface of the device.
The manufacturer of a starter incorporating an overload relay with a means allowing an
automatic restart shall provide, with the starter, any necessary information to alert the user to
the possibility of an automatic restart.
7.1.1 Ambient air temperature
Replace the existing text of this subclause by the following:
Subclause 6.1.1 of IEC 60947-1 applies with the exception that all references to –5 °C are
replaced by 0 °C.
Page 55 and Amendment 1, page 9
8.1.3 Clearances and creepage distances
Replace the existing text of this subclause by the following:
Subclause 7.1.3 of IEC 60947-1 applies with the following note.
NOTE The nature of a semiconductor makes it unsuitable for use for isolation purposes.

Page 59
8.2.1.5 Limits of operation of current operated overload relays and releases
Replace the existing title of this subclause by the following:
8.2.1.5 Limits of operation of current sensing relays and releases
Delete the paragraph preceding subclause 8.2.1.5.1.
8.2.1.5.1 Relays and releases in starters
Replace the existing text of this subclause by the following:

60947-4-2 Amend. 2 © IEC:2006 – 29 –
8.2.1.5.1.1 Limits of operation of time-delay overload relays when all poles are
energized
8.2.1.5.1.1.1 General tripping requirements of overload relays
NOTE 1 The thermal protection of motors in the presence of harmonics in the supply voltage is under
consideration.
The relays shall comply with the requirements of Table 20 when tested as follows:
a) with the overload relay or starter in its enclosure, if normally fitted, and at A times the
current setting, tripping shall not occur in less than 2 h starting from the cold state, at the
value of reference ambient air temperature stated in Table 20. However, when the
overload relay terminals have reached thermal equilibrium at the test current in less than
2 h, the test duration can be the time needed to reach such thermal equilibrium;
b) when the current is subsequently raised to B times the current setting, tripping shall occur
in less than 2 h;
c) for class 2, 3, 5 and 10A overload relays energized at C times the current setting, tripping
shall occur in less than 2 min starting from thermal equilibrium, at the current setting, in
accordance with 9.3.3 of IEC 60034-1;
NOTE 2 Subclause 9.3.3 of IEC 60034-1 states: “Polyphase motors having rated outputs not exceeding
315 kW and rated voltages not exceeding 1 kV shall be capable of withstanding a current equal to 1,5 times
the rated current for not less than 2 min.”.
d) for class 10, 20, 30 and 40 overload relays energized at C times the current setting,
tripping shall occur in less than 4, 8, 12 or 16 min respectively, starting from thermal
equilibrium, at the current setting;
e) at D times the current setting, tripping shall occur within the limits given in Table 19 for the
appropriate trip class and tolerance band, starting from the cold state.
In the case of overload relays having a current setting range, the limits of operation shall
apply when the relay is carrying the current associated with the maximum setting and also
when the relay is carrying the current associated with the minimum setting.
For non-compensated overload relays, the current multiple/ambient temperature characteristic
shall not be greater than 1,2%/K.
NOTE 3 1,2%/K is the derating characteristic of PVC-insulated conductors.
An overload relay is regarded as compensated if it complies with the relevant requirements of
Table 20 at +20 °C and is within the limits shown in Table 20 at other temperatures.
Table 20 – Limits of operation of time-delay overload relays when energized on all poles
Multiples of current setting
Type of overload relay Ambient air temperature values
A B C D
Thermal type not compensated for
1,0 1,2 1,5 7,2 0 °C, +20 °C and +40 °C
ambient air temperature variations
Thermal type compensated for
1,05 1,3 1,5 − 0 °C
ambient air temperature variations
1,05 1,2 1,5 7,2 +20 °C
1,0 1,2 1,5 − +40 °C
Electronic type 1,05 1,2 1,5 7,2 0 °C, +20 °C and +40 °C

60947-4-2 Amend. 2 © IEC:2006 – 31 –
8.2.1.5.1.1.2 Thermal memory test verification
Unless the manufacturer has specified that the device does not contain thermal memory,
electronic overload relays shall fulfil the following requirements (see Figure 3):
− apply a current equal to I until the device has reached the thermal equilibrium;
e
− interrupt the current for a duration of 2 x T (see Table 19) with a relative tolerance
p
of ±10 % (where T is the time measured at the D current according to Table 20);
p
− apply a current equal to 7,2 x I ;
e
− the relay shall trip within 50 % of the time T .
p
i
Tripping shall occur within 50 % of the time T
p
measured at D current according to Table 20
7,2 × I
e
2 × T ± 10 %
p
Time sufficient to reach the thermal equilibrium
I
e
t
IEC  2199/06
Figure 3 – Thermal memory test
8.2.1.5.1.2 Limits of operation of three-pole time-delay overload relays energized on
two poles
With reference to Table 21:
The overload relay or starter shall be tested in its enclosure if normally fitted. With the relay
energized on three poles, at A times the current setting, tripping shall not occur in less than
2 h, starting from the cold state, at the value of the ambient air temperature stated in
Table 21.
Moreover, when the value of the current flowing in two poles (in phase loss sensitive relays,
those carrying the higher current) is increased to B times the current setting, and the third
pole de-energized, tripping shall occur in less than 2 h.
The values shall apply to all combinations of poles.
In the case of overload relays having an adjustable current setting, the characteristics shall
apply both when the relay is carrying the current associated with the maximum setting and
when the relay is carrying the current associated with the minimum setting.

60947-4-2 Amend. 2 © IEC:2006 – 33 –
Table 21 – Limits of operation of three-pole time-delay overload relays
when energized on two poles only
Multiples of current setting
Reference ambient air
Type of overload relay
temperature
A B
Thermal, compensated for ambient 3 poles 2 poles
air temperature variations or 1,0 1,32
electronic
+20 °C
Not phase loss sensitive 1 pole
Thermal, not compensated for 3 poles 2 poles
ambient air temperature variations 1,0 1,25
+40 °C
Not phase loss sensitive 1 pole
Thermal, compensated for ambient
2 poles 2 poles
air temperature variations or 1,0 1,15
electronic
+20 °C
Phase loss sensitive 1 pole 1 pole
0,9 0
Page 59
Add, after 8.2.1.5.2, the following new subclauses:
8.2.1.5.3 Limits of operation of under-current relays
An under-current relay or release, when associated with a switching device, shall operate to
open the switching device within 90 % to 110 % of the set time when the current during
operation is below 0,9 times the under-current setting in all poles.
8.2.1.5.4 Limits of operation of stall relays
A stall relay, when associated with a switching device, shall operate to open the switching
device within 80 % to 120 % of the set time (stall inhibit time) or within the accuracy specified
by the manufacturer, when:
a) current sensing relays: the current is 20 % higher than the set stall current value;
EXAMPLE: Set current of the stall relay: 100 A; set time: 6 s; time setting accuracy: ±10 %. The relay shall trip
within 5,4 s and 6,6 s when the current is equal to or greater than 100 A × 1,2 = 120 A.
b) rotation sensing relays: an input signal indicating no motor rotation exists.
8.2.1.5.5 Limits of operation of jam relays and releases
A jam relay or release, when associated with a switching device, shall operate to open the
switching device within 80 % to 120 % of the set time (jam inhibit time) or within the accuracy
specified by the manufacturer, when the current is above 1,2 times the set current value of
the jam relay, during running after completion of the starting.

60947-4-2 Amend. 2 © IEC:2006 – 35 –
Page 59 and amendment 1, page 11
8.2.2 Temperature rise
Replace the existing text of this subclause by the following:
Subclause 7.2.2 of IEC 60947-1 applies with the following additions.
Temperature rise deviations on the metallic radiator surface of semiconductor devices are
permitted: 50 K in the case where they need not be touched during normal operation.
If the limit of 50 K is exceeded, guarding and location to prevent danger is the responsibility of
the installer. The manufacturer shall provide a suitable warning (e.g. symbol IEC 60417-5041)
in accordance with 6.3.
Amendment 1, page 15
8.2.2.6.1 Uninterrupted and 8 h duty windings
Add, at the end of this subclause, the following note:
NOTE The temperature rise limits given in Table 17 of this standard and in 7.2.2.2 of IEC 60947-1 are applicable
only if the ambient air temperature remains within the limits of 0 °C to +40 °C.
8.2.2.6.2 Intermittent duty windings
Add, at the end of this subclause, the following note:
NOTE The temperature rise limits given in Table 17 of this standard and in 7.2.2.2 of IEC 60947-1 are applicable
only if the ambient air temperature remains within the limits of 0 °C to +40 °C.
Table 17 – Temperature rise limits for insulated coils in air and in oil
Modify the heading of the first column to read:
“Class of insulating material (according to IEC 60085)”

Page 63
8.2.4.1 Operating capability requirements
Replace the existing text of the second paragraph by the following:
For controllers that are designated for utilization categories AC-52a, AC-53a, AC-58a, values
of T corresponding to X values shall not be less than those given in Table 4. For
x
corresponding starters, T shall be the maximum tripping time of its overload relay in
...