IEC 61000-3-12:2011/ISH1:2012

SC 77A/Publication IEC 61000-3-12 (2011), Second edition/I-SH 01
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 3-12: Limits –
Limits for harmonic currents produced by equipment connected to public
low-voltage systems with input current >16 A and ≤75 A per phase


INTERPRETATION SHEET
This interpretation sheet has been prepared by subcommittee 77A: Low frequency
phenomena, of IEC technical committee 77: Electromagnetic compatibility.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
77A/792/ISH 77A/800/RVD

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.
___________
Interpretation of requirements for equipment with unforeseen low input currents during
tests according to IEC 61000-3-12:2011: Electromagnetic compatibility (EMC) – Part 3-
12: Limits – Limits for harmonic currents produced by equipment connected to public
low-voltage systems with input current >16 A and ≤75 A per phase.
When equipment that has a rated current above 16 A draws a reference current that is less
than 16 A under the specified test conditions, the manufacturer may proceed in one of the
following ways:
1) Comply with the proportional limits as calculated, choosing the required R ;
sce
2) Comply with the absolute limits given in IEC 61000-3-2:2011, Table 1, using the
measurement procedure defined in 4.2.2 in IEC 61000-3-12:2011;
In that case, the manufacturer shall state in the instruction manual “Equipment complying
with IEC 61000-3-12”, without having to declare a minimum short circuit power S .
sc
3) Change the test conditions to a representative 2,5 min period, as defined in IEC 61000-3-
12:2011, Table 1 for long cyclic equipment, and comply with the proportional limits as
calculated, choosing the required R .
sce
The manufacturer is strongly advised to state in the test report which of these ways was used,
so that subsequent tests are carried out with the same procedure.


September 2012 ICS 33.100.10 French text overleaf

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SC 77A/Publication CEI 61000-3-12 (2011), Deuxième édition/I-SH 01
COMPATIBILITÉ ÉLECTROMAGNÉTIQUE (CEM) –

Partie 3-12: Limites –
Limite
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