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IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
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IEC 60947-4-1
Edition 4.0 2018-10
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –
Part 4-1: Contactors and motor-starters –
Electromechanical contactors and motor-starters
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by subcommittee 121A: Low-voltage switchgear
and controlgear, of IEC technical committee 121: Switchgear and controlgear and their
assemblies for low voltage.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
121A/336/DISH 121A/342/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
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Interpretation of the first paragraph of 6.2
The reference to 5.2 of IEC 60947-1:2007, IEC 60947-1:2007/AMD1:2010 is intended to cover
the whole subclause where its first paragraph can be discarded.
In particular, the third paragraph of this Subclause 5.2 requiring the marking on the equipment
of manufacturer's name or trademark and type designation or serial number is covering items
a) and b) of 6.1.1 of IEC 60947-4-1:2018.
n o
and of Table 7
Interpretation of footnotes
The standard making conditions for the utilization category AC-3e are defined by the ratio
o
I / I equal to 12 with the corresponding value of Cos ϕ in footnote .
e
n
Footnote provides the possibility to select an alternate value of the ratio I / I between 12
e
and 13, and gives the corresponding equations to determine the value of Cos ϕ.
ICS 29.120.99; 29.130.20
IEC 60947-4-1:2018-10/ISH1:2020-03(en-fr)
– 2 – IEC 60947-4-1:2018/ISH1:2020
IEC 2020
Interpretation of the rated operational current of Table 13 and Table 14
Tables 13 and 14 are intended to be used for contactors and starters specified for motor
loads. If the contactor or starter is specified with more than one motor load utilization category
(AC-2, AC-3, AC-3e or AC-4), the rated operational current I corresponding to the utilization
e
category AC-3 is preferred for determining the prospective current “r” for the test.
The utilization category AC-3 is considered as the most representative use case and is
deemed to cover the other motor utilization categories.
IEC 2020
COMMISSION ÉLECTROTECH
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