IEC 61326-3-2:2008/ISH1:2013

SC 65A/Publication 61326-3-2 (2008), First edition/I-SH 01
ELECTRICAL EQUIPMENT FOR MEASUREMENT,
CONTROL AND LABORATORY USE –
EMC REQUIREMENTS –
Part 3-2: Immunity requirements for safety-related
systems and for equipment intended to perform
safety-related functions (functional safety) –
Industrial applications with specified
electromagnetic environment
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by subcommittee 65A: System aspects, of IEC
technical committee 65.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
65A/632/ISH 65A/644/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.
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Introduction
IEC 61326-3-2:2008 gives immunity requirements for safety-related systems and for
equipment intended to perform safety-related functions (functional safety) in industrial
applications with specified electromagnetic environment. The actual immunity levels, test
parameters and applicable basic standards are listed in Table 1a to Table 1f of that standard.
In case of the phenomenon “Conducted r.f.” the basic standard IEC 61000-4-6:2004 shall be
applied. The frequency range under consideration in IEC 61326-3-2:2008 is from 10 kHz to 80
MHz though the basic standard IEC 61000-4-6:2004 lists calibration parameters for the
frequency range from 150 kHz to 80 MHz only. This lack in having some information
concerning the calibration was the reason for having introduced footnote c in Table 1b (and
for the identical footnotes regarding this phenomenon in the other tables).
However, footnote c in Table 1b leaves some space for interpretation as it is not entirely clear
whether it applies to the entire calibration situation for all types of injection methods or to that
one of CDNs only, as in the first case some information would be missing for the situation of
testing via clamp injection.
Interpretation:
Footnote c in Table 1b shall be interpreted as follows:
The basic standard IEC 61000-4-6:2004 allows different injection methods, and their selection
shall be done according to the rules for selecting injection methods and test points (see 7.1 of
IEC 61000-4-6:2004).
June 2013 ICS 25.040.40; 33.100.20

In case the CDN injection method is applied the impedance of the CDN in the frequency range
10 kHz up to 150 kHz has to comply with the asymmetric impedance requirements of
IEC 61000-4-6:2004 at 150 kHz. Calibration shall be performed in accordance with
IEC 61000-4-6:2004. Sufficient decoupling can be demonstrated if the impedance criterion is
met both with the AE port short-circuited and then open-circuited.
In case the clamp injection is applied the procedures of 7.3 or 7.4 of the basic standard
IEC 61000-4-6:2004 are applicable in the frequency range from 10 kHz to 150 kHz as well.

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June 2013 ICS 25.040.40; 33.100.20

SC 65A/Publication 61326-3-2 (2008), Première édition/I-SH 01
MATÉRIEL ÉLECTRIQUE DE MESURE,
DE COMMANDE ET DE LABORATOIRE –
EXIGENCES RELATIVES À LA CEM –

Partie 3-2: Exigences d'immunité pour les sys
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