IEC 60947-8:2003/AMD2:2011

IEC 60947-8 ®
Edition 1.0 2011-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 2
AMENDEMENT 2
Low-voltage switchgear and controlgear –
Part 8: Control units for built-in thermal protection (PTC) for rotating electrical
machines
Appareillage à basse tension –
Partie 8: Unités de commande pour la protection thermique incorporée (CTP)
aux machines électriques tournantes

IEC 60947-8:2003/A2:2011
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IEC 60947-8 ®
Edition 1.0 2011-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 2
AMENDEMENT 2
Low-voltage switchgear and controlgear –
Part 8: Control units for built-in thermal protection (PTC) for rotating electrical
machines
Appareillage à basse tension –
Partie 8: Unités de commande pour la protection thermique incorporée (CTP)
aux machines électriques tournantes

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE PRICE CODE
G
CODE PRIX
ICS 29.130.20 ISBN 978-2-88912-500-5

– 2 – 60947-8 Amend.2  IEC:2011
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/1732/FDIS 17B/1739/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 publication will remain unchanged until
the stability 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• withdrawn,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.
_____________
2 Normative references
Add the following references:
IEC 60068-2-1, Environmental testing – Part 2-1: Tests – Test A: Cold
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules

Update the existing normative references as follows:
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) - Part 4-3: Testing and
measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1 (2007)
Amendment 2 (2010)
IEC 61000-4-4:2004, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
Amendment 1 (2010)
IEC 61000-4-5:2005, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
Corrigendum 1 (2009)
60947-8 Amend.2  IEC:2011 – 3 –
IEC 61000-4-6:2008, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
IEC 61000-4-8:2009, Electromagnetic compatibility (EMC) – Part 4-8: Testing and
measurement techniques – Power frequency magnetic field immunity test
IEC 61000-4-11:2004, Electromagnetic compatibility (EMC) – Part 4-11: Testing and
measurement techniques – Voltage dips, short interruptions and voltage variations immunity
tests
IEC 61000-4-13:2002, Electromagnetic compatibility (EMC) – Part 4-13: Testing and
measurement techniques – Harmonics and interharmonics including mains signalling at a.c.
power port, low-frequency immunity tests
Amendment 1 (2009)
CISPR 11:2009, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
Amendment 1 (2010)
CISPR 22:2008, Information technology equipment – Radio disturbance characteristics –
Limits and methods of measurement

6.1 Nature of information
Replace item c by the following:
c) 60947-8
The Mark A control units shall be additionally marked “Mark A control unit”.

8.1 Constructional requirements
Add the following subclause number and title to the existing text under 8.1:
8.1.1 General
Add the following subclauses at the end of the new Subclause 8.1.1:
8.1.2 Materials
8.1.2.1 General materials requirements
Subclause 7.1.2.1 of IEC 60947-1:2007 applies.
8.1.2.2 Glow wire testing
Subclause 7.1.2.2 of IEC 60947-1:2007 applies with the following addition.
When tests on the equipment or on sections taken from the equipment are used, parts of
insulating materials necessary to retain current-carrying parts in position shall conform to the
glow-wire tests of 8.2.1.1.1 of IEC 60947-1:2007 at a test temperature of 850 °C.

– 4 – 60947-8 Amend.2  IEC:2011
8.1.2.3 Test based on flammability category
Subclause 7.1.2.3 of IEC 60947-1:2007 applies.
8.1.3 Current-carrying parts and their connections
Subclause 7.1.3 of IEC 60947-1:2007 applies.
8.1.4 Clearances and creepage distances
Subclause 7.1.4 of IEC 60947-1:2007 applies.
8.2.9 Damp heat
Replace the existing Subclause 8.2.9, including the title, by the following:
8.2.9 Environmental testing
Clause B.2 applies.
8.3.2.2 Equipment incorporating electronic circuits
Replace the third paragraph of Subclause 8.3.2.2 by the following:
Performance criteria are based on the acceptance criteria given in Table 24 of
IEC 60947-1:2007 and are changed as follows:
Performance criterion A:
On line "Operation of power and control circuits",
replace:
"No unwanted operation"
by:
"During the tests, the output state of the switching element shall not change."
Performance criterion B:
On line "Operation of power and control circuits",
replace:
"Temporary degradation or loss of performance which is self-recoverable"
by:
"During the tests, the output state of the switching element shall not change for more than 1
ms for d.c. devices or one half-wave of supply frequency for a.c. devices."
Performance criterion C:
On line "Operation of power and control circuits",
replace:
"Temporary degradation or loss of performance which requires operator intervention or
system reset."
by:
"Temporary degradation or loss of performance which is self recoverable or requires system
reset."
The performance criteria shall be performance criterion A in general, except as follows:
• for electrostatic discharges, for fast transient/burst, for surges and for voltage dips “0 %
during 0,5 cycle and 0 % during 1 cycle”, performance criterion B shall be fulfilled;
• for voltage dips “70 % during 25/30 cycles” and for short time interruptions, performance
criterion C shall be fulfilled.

60947-8 Amend.2  IEC:2011 – 5 –
Table 1 – Tests for EMC – Immunity
Replace the existing Table 1 by the following new Table 1:
Type of test Test level required
Electrostatic discharge immunity test 8 kV / air discharge
IEC 61000-4-2 or
4 kV / contact discharge
d
Radiated radio-frequency electromagnetic field immunity 10 V/m
test 80 MHz to 1 GHz
IEC 61000-4-3
Radiated radio-frequency electromagnetic field immunity 3 V/m
test 1 GHz to 2 GHz
IEC 61000-4-3
Radiated radio-frequency electromagnetic field immunity 1 V/m
test 2 GHz to 2,7 GHz
IEC 61000-4-3
a
Electrical fast transient/burst immunity test 2 kV on power ports
b
IEC 61000-4-4 1 kV on signal ports
2 kV (line to earth)
1,2/50 μs – 8/20 μs surge immunity test
c
1 kV (line to line)
IEC 61000-4-5
Conducted radio-frequency immunity test 10 V
(150 kHz to 80 MHz)
IEC 61000-4-6
Power-frequency magnetic field immunity test 30 A/m
f)
IEC 61000-4-8
g, h
Voltage dips immunity test Class 2
IEC 61000-4-11
0 % during 0,5 cycle
and
0 % during 1 cycle
70 % during 25/30 cycles
g, h
Voltage interruptions immunity test Class 2
IEC 61000-4-11
0 % during 250/300 cycles
e
Immunity to harmonics in the supply No requirements
IEC 61000-4-13
a
Power port: the point at which a conductor or cable carrying the primary electrical power needed for the
operation of an equipment or associated equipment is connected.
b
Signal port: the point at which a conductor or cable carrying information for transferring data or signals is
connected to the equipment.
c
Not applicable for ports with a rated voltage of 24 V d.c. or less.
d
Except for the ITU broadcast frequency bands 87 MHz to 108 MHz, 174 MHz to 230 MHz and 470 MHz to 790
MHz, where the level shall be 3 V/m.
e
Future requirements are under study.
f
Applicable only to equipment containing devices sensitive to power frequency magnetic fields.
g
The given percentage means percentage of the rated operational voltage, e.g. 0 % means 0 V.
h
The value in front of the slash mark (/) is for 50 Hz and the value behind is for 60 Hz tests.

– 6 – 60947-8 Amend.2  IEC:2011
B.2 Damp heat
Replace the existing Clause B.2 in Amendment 1 by the following new Clause B.2:
B.2 Special tests- Damp heat, salt mist, vibration and shock
For these special tests, Annex Q of IEC 60947-1:2007 applies with the following additions.
Where Table Q.1 of IEC 60947-1:2007 calls for verification of operational capability, this shall
be made by carrying out the “Verification of switch on and switch off of Mark A control units”.
The test is done while a variable resistance is inserted between each pair of terminals
intended for the connection of the thermistor detectors. The following conditions a) to c) shall
be met.
a) For any resistance value of 750 Ω or less, the control unit shall be switched on, or shall be
able to be reset. Compliance with this condition shall be checked by testing with a variable
resistance set to this value. In case of doubt, this check shall also be carried out at a
lower value of resistance.
b) When the resistance value is increased (at a uniform rate of approximately 250 Ω/s), the
control unit shall switch off when the resistance value is in the range of 1650 Ω to 4000 Ω.
c) The control unit shall be left in tripped condition for 1 min; after which the resistance value
shall be lowered
...