EN IEC 60255-26:2025/prA1:2026

• Status: Not Published
• Publication Date: 08-Feb-2028
• ICS: 29.120.70 - Relays
• Technical Committee: CLC/TC 95X - Measuring relays and protection equipment
• Current Stage: 4020 - Enquiry circulated - Enquiry
• Start Date: 04-Sep-2026
• Due Date: 30-Jan-2026
• Completion Date: 04-Sep-2026
• Ref Project: SIST EN IEC 60255-26:2025/oprA1:2026 - Measuring relays and protection equipment - Part 26: Electromagnetic compatibility requirements - Amendment 1

• Amends: EN IEC 60255-26:2025 - Measuring relays and protection equipment - Part 26: Electromagnetic compatibility requirements
• Effective Date: 16-Sep-2025

EN IEC 60255-26:2025/prA1:2026 is a CENELEC amendment to IEC 60255-26 for measuring relays and protection equipment. It updates the electromagnetic compatibility (EMC) requirements for this equipment, including port definitions, emission limits, immunity test methods and acceptance criteria.

What does EN IEC 60255-26:2025/prA1:2026 specify?

EN IEC 60255-26:2025/prA1:2026 specifies amendment text for Part 26, which is the EMC requirements document for measuring relays and protection equipment. In practice, it revises how these products are named, which ports are tested, which basic EMC methods are used, and how compliance is judged.

The amendment is organized by changes to the foreword, Clause 3 on terms and definitions, Clause 5 on emission, Clause 6 and Clause 7 on immunity tests, Clause 8 on acceptance criteria, and Annex A on power frequency immunity tests on binary inputs.

Annex	What it covers
Annex A (normative)	Power frequency immunity tests on binary inputs

What are the key requirements of EN IEC 60255-26:2025/prA1:2026?

The amendment matters most where it changes port definitions, test application, and acceptance criteria. It also tightens the link between the relay function, the port type, and the EMC test method, so test plans and product documentation need to match the actual hardware.

Port definitions and what is tested

Clause 3 adds definitions for DC power output port, Analogue input signal port, and Pick-up signal. The new terms separate a DC output used to energize auxiliary equipment from ports used for communication, and they identify analogue inputs as low-level measurement interfaces such as RTD and 20 mA loops.

For users, this means the EMC test set-up has to follow the real port function, not just the connector type. That affects how laboratories wire the equipment and how manufacturers describe ports in documentation.

Emission requirements

Clause 5.2 adds that no conducted emission requirements apply to DC power output ports when CISPR H standards are used. Clause 5.1 also revises the radiated emission table above 1 GHz and confirms that measuring relays and protection equipment are treated as apparatus that satisfy class A limits.

In practice, a buyer or lab should check which port types are in scope before planning emission tests. The amendment also keeps the need to use the more stringent limit at the transition frequency and to normalize measurements made at different distances when required.

Immunity tests are now more port-specific

Clauses 6 and 7 update the immunity tables for signal/control ports, wired network ports, input ports, output ports, DC power output ports, earth ports, and auxiliary power supply ports. The amendment aligns the coupling method and the applied test level with the specific port category.

That matters because a single generic EMC test is no longer enough for all interfaces. The test plan has to distinguish, for example, between ports for communication, ports for measurement, and ports that only provide DC power to auxiliary equipment.

ESD, radiated field, EFT, surge, and conducted RF tests

Clause 7.3.2 updates the electrostatic discharge test so the equipment under test is placed as installed as possible, with discharge points chosen from normally accessible surfaces and controls. Clause 7.3.3 updates the radiated electromagnetic field immunity test and keeps the requirement to test the relevant sides of the enclosure, with extra surfaces considered when ventilation slots or non-metallic enclosures are present.

Clause 7.3.4 through 7.3.7 update electrical fast transient/burst, damped oscillatory wave, surge, and conducted RF immunity. The tables now include DC power output ports, revised coupling methods, and clearer rules for when a port is not tested because the connected cable is permanently short or otherwise outside the intended test case.

For users, this means the EMC report must show the exact cable arrangement, the port grouping, and the chosen coupling method. Small changes in wiring or cabinet installation can change which tests apply.

Power-related immunity on auxiliary supply ports

Clauses 7.3.10, 7.3.11, and 7.3.12 update voltage dips and short interruptions, ripple on DC input power port, and gradual shutdown/start-up tests. These sections make clear that the applied test level is based on the declared rated voltage, and where a range exists, the lowest or highest declared value may govern the test case.

This is important for products that can run on either AC or DC or on a rated voltage range. The manufacturer has to state the intended supply mode and document the test condition used.

Acceptance criteria

Clause 8.2 revises the acceptance criteria for immunity. For protection functions, the document now explicitly includes pick-up signals in the normal-performance condition, and it treats analogue output ports and DC power output ports together in the criteria tables.

For practice, this tells a test laboratory what counts as acceptable behavior during and after EMC stress. It also tells a manufacturer what has to be stable, what can degrade temporarily, and what must recover by itself.

Annex A binary input testing

Annex A updates the power frequency immunity tests on binary inputs. The amendment also changes Figure A.3 and clarifies how many identical circuits must be sampled when several identical binary input circuits are present.

That helps labs verify input circuits without testing every identical path individually, while still keeping the result representative of the design.

What terms does EN IEC 60255-26:2025/prA1:2026 define?

• DC power output port - an output port of a DC power supply interface used to energize auxiliary equipment, not for communication.
• Analogue input signal port - an input signal port whose value is directly proportional to the measured physical quantity and is used for low-level analogue interfaces such as RTD and 20 mA inputs.
• Pick-up signal - an output signal that asserts when the measuring relay or protection equipment starts.
• Low-power current transformer (LPCT) - a low-power current transformer input port used as a specific EMC test category in the tables.
• Low-power voltage transformer (LPVT) - a low-power voltage transformer input port used as a specific EMC test category in the tables.
• Binary input port - an input used to register DC or AC and DC voltages, with Annex A giving the power-frequency test approach for these circuits.

Who uses EN IEC 60255-26:2025/prA1:2026?

IEC 60255-26:2025/prA1:2026 is used by relay manufacturers, EMC test laboratories, certification bodies, utilities, and engineering teams working on transmission and distribution protection equipment. Quality managers and buyers use it to specify which EMC tests and acceptance criteria must appear in a test report or product dossier.

It is especially relevant when a product has mixed interfaces, such as measurement inputs, binary inputs, communication ports, and DC auxiliary power output ports. Those users need the document to decide which ports are tested, how to configure the equipment under test, and what counts as pass or fail.

What changed in EN IEC 60255-26:2025/prA1:2026 from the previous edition?

EN IEC 60255-26:2025/prA1:2026 is an amendment to IEC 60255-26:2023. The amendment changes the following points:

• replaces the figure in Clause 3.1.23
• adds definitions for DC power output port, Analogue input signal port, and Pick-up signal
• adds a clause note that no conducted emission requirements apply to DC power output ports with CISPR H standards
• corrects the radiated emission limit above 1 GHz
• revises immunity tables for signal/control ports, wired network ports, input ports, output ports, DC power output ports, and earth ports
• updates electrostatic discharge, radiated field, EFT, damped oscillatory wave, surge, conducted RF, power frequency magnetic field, voltage dip, ripple, and gradual shutdown/start-up test provisions
• updates acceptance criteria to include pick-up signals and DC power output ports
• revises Annex A and Figure A.3

Which standards are used with EN IEC 60255-26:2025/prA1:2026?

The amendment uses the following standards and standard families as its test basis:

• IEC 61000-4-2 - electrostatic discharge immunity
• IEC 61000-4-3 - radiated electromagnetic field immunity
• IEC 61000-4-4 - electrical fast transient/burst immunity
• IEC 61000-4-5 - surge immunity
• IEC 61000-4-6 - conducted RF immunity
• IEC 61000-4-8 - power frequency magnetic field immunity
• IEC 61000-4-11 - voltage dips and short interruptions
• IEC 61000-4-16 - ripple and related power-frequency conducted immunity on DC input power ports
• IEC 61000-4-17 - ripple on DC input power port immunity
• IEC 61000-4-18 - damped oscillatory wave immunity
• IEC 61000-4-29 - additional support for voltage dip and interruption testing
• CISPR 11 - reference for radiated emission below 1 GHz
• CISPR 32 - reference for radiated emission above 1 GHz
• CISPR H standards - reference family for conducted emission treatment of DC power output ports
• IEC 60050-447:2020-05 - source for the modified definition of analogue input signal port

What does the EN IEC 60255-26:2025/prA1:2026 document contain?

EN IEC 60255-26:2025/prA1:2026 contains revised test tables, coupling arrangements, port categories, acceptance criteria, and annex material for EMC evaluation of measuring relays and protection equipment. The tables cover emission limits and immunity procedures, including test set-ups for enclosure ports, signal/control ports, wired network ports, input and output ports, earth ports, and DC power output ports.

It also contains detailed instructions for mounting, support, dwell time, waveform characteristics, and the configuration of the equipment under test. For laboratories, the practical value is that the document tells them how to set up the test, which ports to stimulate, and what performance to observe during and after the test.

SLOVENSKI STANDARD
SIST EN IEC 60255-26:2025/FprA1:2026
01-november-2026
Merilni releji in zaščitna oprema - 26. del: Zahteve za elektromagnetno združljivost
- Dopolnilo A1
Measuring relays and protection equipment - Part 26: Electromagnetic compatibility
requirements - Amendment 1
Messrelais und Schutzeinrichtungen - Teil 26: Anforderungen an die elektromagnetische
Verträglichkeit
Relais de mesure et dispositifs de protection - Partie 26: Exigences de compatibilité
électromagnétique
Ta slovenski standard je istoveten z: EN IEC 60255-26:2025/prA1:2026
ICS:
29.120.70 Releji Relays
33.100.01 Elektromagnetna združljivost Electromagnetic compatibility
na splošno in general
SIST EN IEC 60255-26:2025/FprA1:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN IEC 60255-26:2025/FprA1:2026

SIST EN IEC 60255-26:2025/FprA1:2026
95/646/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60255-26/AMD1 ED4
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-09-04 2026-11-27
SUPERSEDES DOCUMENTS:
95/600/CD, 95/606/CC
IEC TC 95 : MEASURING RELAYS AND PROTECTION EQUIPMENT
SECRETARIAT: SECRETARY:
France Mr Thierry BARDOU
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 14,TC 17,TC 38,TC 77,TC 115,TC 122
ASPECTS CONCERNED:
Electricity transmission and distribution,Electromagnetic Compatibility
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
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This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
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Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Amendment 1 - Measuring relays and protection equipment - Part 26: Electromagnetic
compatibility requirements
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
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SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
1 INTERNATIONAL ELECTROTECHNICAL COMMISSION
2 ____________
4 MEASURING RELAYS AND PROTECTION EQUIPMENT –
6 Part 26: Electromagnetic compatibility requirements
8 AMENDMENT 1
10 FOREWORD
11 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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46 shall not be held responsible for identifying any or all such patent rights.
47 Amendment 1 to IEC 60255-26:2023 has been prepared by subcommittee MT2:
48 electromagnetic Compatibility (EMC) Requirements for Measuring Relays and Protection
49 Equipment, of IEC technical committee 95: Measuring relays and protection equipment.
50 The text of this Amendment is based on the following documents:
Draft Report on voting
XX/XX/XXXX XX/XX/XXX
52 Full information on the voting for its approval can be found in the report on voting indicated in
53 the above table.
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
54 The language used for the development of this Amendment is English.
55 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
56 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
57 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
58 described in greater detail at www.iec.ch/publications/.
59 The committee has decided that the contents of this document will remain unchanged until the
60 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
61 specific document. At this date, the document will be
62 • reconfirmed,
63 • withdrawn, or
64 • revised.
SIST EN IEC 60255-26:2025/FprA1:2026
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69 3  Terms and definitions
70 3.1.23
71 Replace the Figure by the following
75 Add the following new definitions:
76 3.1.28
77 DC power output port
78 output port of a DC power supply interface to energize auxiliary equipment. The DC power
79 output port is not used for communicating with auxiliary equipment.
80 3.1.29
81 Analogue input signal port
82 input signal whose value is directly proportional to measured physical quantity with a maximum
83 voltage of less than 50 V and a maximum current of less than 100 mA. (e.g. RTD, 20 mA
84 interface)
85 [SOURCE: IEC 60050-447:2020-05, 447-03-19, modified – “with a maximum voltage of less than 50 V and a maximum
86 current of less than 100 mA. (e.g. RTD, 20 mA interface)” has been added to the definition]
87 3.1.30
88 Pick-up signal
89 output signal that asserts when a measuring relay or protection equipment starts (picks up)
90 [SOURCE: IEC 60050-447:2020-05, 447-04-13]
91 Note 1: Start signal (pick-up signal), among all output signals, can be dedicated or not.
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
94 5.2  Conducted emission
95 Add the following text before Table 3
96 No conducted emission requirements apply to DC power output ports in conjunction with CISPR
97 H standards
99 5.1  Radiated emission
100 Replace table 1 with the following new table
101 - Radiated emission limit (above 1 GHz) has been corrected in item 1.2 based on CISPR 32:2015/AMD1:2019
103 Table 1 – Radiated emission tests – Enclosure port
Reference Test
standard procedure
Environmental
Item Frequency range Limits (reference to
phenomena
this
document)
40 dB (µV/m) quasi­peak
at 10 m
30 MHz to 230 MHz
50 dB (µV/m) quasi­peak
Radiated
at 3 m
emission
1.1 CISPR 11 See 7.2.2
a
47 dB (µV/m) quasi­peak
(below 1 GHz)
at 10 m
230 MHz to 1 000 MHz
57 dB (µV/m) quasi­peak
at 3 m
60 dB (µV/m) average
Radiated
at 3 m
1.2 emission 1 GHz to 6 GHz CISPR 32 See 7.2.2
80 dB (µV/m) peak
(above 1 GHz)
at 3 m
a
Measuring relays and protection equipment are apparatus which satisfy the class A limits. Limits can be
measured at a nominal distance of 3 m or 10 m or 30 m. A measuring distance less than 10 m is allowed only
for equipment which complies with the definition for "small equipment" given in 3.1.26. In the case of
measurements at a separation distance of 30 m, an inverse proportionality factor of 20 dB per decade shall be
used to normalize the measured data to the specified distance for determining compliance.
At the transition frequency, the more stringent limit shall apply.
107 6.3  Immunity of signal/control port and wired network port
108 Replace table 7 with the following new table
109 - source impedance is removed from the item 7.4 to prevent inconsistencies with the application of the EMC
110 basic standard.
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111 Table 7 – Immunity tests – signal/control port and wired network port
Item Environmental Test Units Basic EMC Test Acceptance
phenomena specification publication procedure criteria
(see 8.2)
7.1 Conducted disturbance
induced by radio-
frequency fields
Frequency sweep
Test frequency range 0,15 to 80 MHz
Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
IEC
Frequency step size ≤ 1 % (of preceding
See 7.3.7 A
61000-4-6
frequency value)
Spot frequencies
Test spot frequencies 27 ± 0,135 MHz

Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
7.2 Electrical fast
transient/burst
Rise time t /    5 / 50 ns
r
Pulse duration t
d
IEC
Test level
See 7.3.4 B
61000­4­4
Zone A 4 kV (peak voltage)
Zone B 2 kV (peak voltage)
Repetition frequency 5 kHz
Source impedance 50 Ω
7.3 Damped oscillatory
waves
Voltage oscillation 1 MHz
frequency
Test level
Common mode 1 kV (peak voltage)
IEC
See 7.3.5 B
61000-4-18
Zone A
Voltage oscillation 3/10/30 MHz
frequency
Test level
Common mode 2 kV (peak voltage)

SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
7.4 Surge
Front time / 1,2/50 (8/20) µs voltage (current)
Time to half value
Test level
Line-to-Line
IEC
See 7.3.6 B
Zone A 0,5 1 2  kV 61000-4-5
Zone B 0,5 1   kV
Line-to-earth
Zone A 0,5 1 2 4 kV
Zone B 0,5 1 2  kV
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IEC CDV 60255-26/AMD1 © IEC 2026
115 Replace the title of clause 6.4 by the following one
117 6.4 Immunity of input, output and DC power output port
118 Replace table 8 with the following new table
119 - Title of the table is updated.
120 - Coupling resistor and coupling capacitor are removed from Item 8.4 for line-to-line and line-to-earth tests
121 to prevent inconsistencies with the application of the EMC basic standard.
122 - Note b is updated
123 Table 8 – Immunity tests – Input, output and DC power output port
Item Environmental Test Units Basic EMC Test Acceptance
phenomena specification publication procedure criteria
(see 8.2)
8.1 Conducted disturbance
induced by radio-
frequency fields
Frequency sweep
Test frequency range 0,15 to 80 MHz
Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
IEC
Frequency step size ≤ 1 % (of preceding
See 7.3.7 A
61000-4-6
frequency value)
Spot frequencies
Test spot frequencies 27 ± 0,135 MHz

Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
8.2 Electrical fast
transient/burst
Rise time t /    5 / 50 ns
r
Pulse duration t
d
IEC
Test level
See 7.3.4 B
61000-4-4
Zone A 4 kV (peak voltage)
Zone B 2 kV (peak voltage)
Repetition frequency 5 kHz
Source impedance 50 Ω
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
8.3 Damped oscillatory
waves
Voltage oscillation 1 MHz
frequency
Test level
a
1 kV (peak voltage)
Differential mode
Common mode 2,5 kV (peak voltage)
IEC
See 7.3.5 B
61000-4-18
Zone A
Voltage oscillation
3/10/30 MHz
frequency
Test level
Common mode 2 kV (peak voltage)

b
8.4
Surge
Front time / 1,2/50 (8/20) µs voltage (current)
Time to half value
Test level
Line-to-line
IEC
See 7.3.6 B
Zone A 0,5 1 2 kV 61000-4-5
Zone B 0,5 1 kV
Line-to-earth
Zone A 0,5 1 2 4 kV
Zone B 0,5 1 2 kV
c
8.5
Power frequency
Zone A
Test voltage 150 V (RMS)
Differential mode
Coupling resistor 100 Ω
Coupling capacitor 0,1 µF
Test voltage 300 V (RMS)
Common mode
Coupling resistor 220 Ω
IEC
See 7.3.8 A
Coupling capacitor 0,47 µF
61000-4-16
Zone B
Test voltage 100 V (RMS)
Differential mode
Coupling resistor 100 Ω
Coupling capacitor 0,047 µF
Test voltage 300 V (RMS)
Common mode
Coupling resistor 220 Ω
Coupling capacitor 0,47 µF
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
a
In more severe environments a differential test voltage of 2,5 kV may be required for current and voltage
transformer inputs.
b
Shielded ports (e.g. Low-power current transformer (LPCT) and low-power voltage transformer (LPVT) input
ports) shall be tested in accordance with IEC 61000-4-5:2014, 7.6. and unshielded ports shall be tested in
accordance with IEC 61000-4-5:2014, 7.4 or 7.5.
c
The power frequency test is only applicable to binary input ports that register only DC or both AC and DC
voltages. Binary input ports that can register only AC voltages are excluded from this test. Dual rated AC and
DC input may have AC or DC mode selection based on hardware or software settings; in that case the test shall
be done with selection in DC mode only. See Annex A for specification of generator and CDN and Annex B for
background information for power frequency tests.
125 6.5  Immunity of earth port
126 Replace in Table 9 the existing note at the bottom by the following:
127 Multiple earth ports shall be tested separately.
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131 7.3.2  Electrostatic discharge immunity test
132 Replace Table 12 with the following new table
133 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
134 Table 12 – Electrostatic discharge immunity test
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
The EUT is placed in its case or housing in as close to
Details of mounting and support
installed conditions as possible.
Tests on the enclosure shall be applied as follows:
– the contact discharge method is the preferred method;
– the air discharge method shall only be used when the
Discharge method accessible surfaces of the EUT are non-conducting;
– the direct and indirect application test method shall be
used.
For test set-up of different applications, see IEC 61000­4-2.
The points selected for the application of the test shall be
those which are accessible to the operator under normal
operating conditions, including communication ports and
Application of the discharges
those points for setting adjustments that can only be
accessed by removing a cover.
See furthermore IEC 61000-4-2:2008, Table 4
Test voltage See Table 5, item 5.2.
The relay shall be energized as given under EUT
configuration and the relay settings shall comply with
7.3.1.6.
Since the coincidence of electrostatic discharges and a
primary fault is considered to be unlikely, the effect of the
electrostatic discharges on the EUT in its transitional or
operate condition is not considered.
Setting adjustments which necessitate any action other than
removal of the cover, such as removal of a module, are not
included.
The application of discharge to any point of the equipment
which is accessible only for repair and maintenance
Test application
purposes is outside the scope of this document. In the
selection of test points, tests shall be carried out on the
following:
– knobs, push-buttons, switches, communication interfaces,
etc., accessible under normal service;
– points on covers of insulating material where conducting
parts are close to the inside of the cover;
– points on conducting parts not belonging to, but placed in
the vicinity of, the EUT, when this has an insulating cover.
The selected test points shall be recorded in the test report.
Testing shall be carried out at all levels given in Table 5,
item 5.2.
Basic EMC publication IEC 61000-4-2
Acceptance criteria See Table 5, item 5.2.
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
138 7.3.3  Radiated electromagnetic field immunity test
139 Replace Table 13 with the following new table
140 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
141 Table 13 – Radiated electromagnetic field immunity test (frequency sweep)
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Details of mounting and support The EUT is placed in the calibrated UFA.
Frequency range to be swept See Table 5, item 5.1.
RF Modulation 80 % AM (1 kHz)
The dwell time of the amplitude modulated carrier at each
frequency shall not be less than the time necessary for the
Dwell time
EUT to be exercised and to respond, but shall in no case be
less than 0,5 s.
Test field strength See Table 5, item 5.1.
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
All other ports of the relay shall remain in their initial
Test application
condition. The tests shall be performed on the front, back,
left and right side of the EUT. Additional tests are required
for sides with ventilation slots or all 6 sides if the enclosure
is non-metallic. This shall be evaluated during a risk
assessment.
Basic EMC publication IEC 61000-4-3
Acceptance criteria See Table 5, item 5.1.
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
145 Replace Table 14 with the following new table
146 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
147 Table 14 – Radiated electromagnetic field immunity test (spot frequencies)
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Details of mounting and support The EUT is placed in the calibrated UFA.
Spot frequencies See Table 5, item 5.1.
RF Modulation 80 % AM (1 kHz)
Test duration ≥ 10 s
The dwell time at each spot frequency shall be sufficient for
Dwell time the EUT to change from the test reference condition to the
operate state.
Test field strength See Table 5, item 5.1.
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
During each spot frequency test, the input energizing
quantities shall be adjusted to cause the EUT to change
from the test reference conditions to the operated state and
held until the EUT operates correctly. The input energizing
quantities shall then be re-adjusted to cause the EUT to go
Test application
back to test reference conditions.
Background information on the spot frequency test can be
found in Annex C.
The tests shall be performed on the front, back, left and
right side of the EUT. Additional tests are required for sides
with ventilation slots or for all 6 sides if the enclosure is
non-metallic. This shall be evaluated during a risk
assessment.
Basic EMC publication IEC 61000-4-3
Acceptance criteria See Table 5, item 5.1.
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
150 7.3.4  Electrical fast transient/burst immunity test
151 Replace Table 15 with the following new table
152 - Item “EUT configuration”, in the “Test procedure” column,
153 o Test Case 1: the indication “(AC or DC)” is added
154 o Test case 2: the indication “(AC and DC)” is added
155 - Item “Coupling method”, the DC power output port is added.
rd
156 - Item “Test application”, in the column “Test procedure”, 3 paragraph, the term “functional” is suppressed
157 and the text becomes “For the earth port, the fast transient/burst test is not…”
158 Table 15 – Electrical fast transient/burst immunity test
Test set-up Test procedure
Test case 1:
Auxiliary power supply ports: lowest rated value (AC or DC)
All other ports: test reference conditions (see 7.3.1.2)
Test case 2:
EUT configuration
Auxiliary power supply ports: highest rated value (AC and
DC)
All other ports: test reference conditions (see 7.3.1.2)
For test case 2 only auxiliary power supply ports and the
battery monitor ports need to be subjected to the test.
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Where the EUT is mounted in a cabinet, the tests may be
conducted on the EUT mounted in that particular cabinet. No
Details of mounting/support
test shall be performed on interconnecting cables within the
same cabinet.
Coupling methods
Auxiliary power supply ports CM with CDN
AC current and voltage input ports CM with CDN
LPIT input ports CM with CCC
Earth port CM with CDN
DC power output ports CM with CDN
Input ports CM with CCC
Output ports CM with CCC
Signal/control ports and wired network ports CM with CCC
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Test voltage
Table 9, item 9.2.
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Repetition frequency
Table 9, item 9.2.
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Test wave form characteristic
Table 9, item 9.2
SIST EN IEC 60255-26:2025/FprA1:2026
IEC CDV 60255-26/AMD1 © IEC 2026
Test set-up Test procedure
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
All auxiliary equipment used to provide the EUT with signal
for normal operation, and to verify the correct operation of
the EUT, shall be decoupled.
For the earth port, the fast transient/burst test is not
applicable to t
...

SLOVENSKI STANDARD
01-november-2026
Merilni releji in zaščitna oprema - 26. del: Zahteve za elektromagnetno združljivost
- Dopolnilo A1
Measuring relays and protection equipment - Part 26: Electromagnetic compatibility
requirements - Amendment 1
Messrelais und Schutzeinrichtungen - Teil 26: Anforderungen an die elektromagnetische
Verträglichkeit
Relais de mesure et dispositifs de protection - Partie 26: Exigences de compatibilité
électromagnétique
Ta slovenski standard je istoveten z: EN IEC 60255-26:2025/prA1:2026
ICS:
29.120.70 Releji Relays
33.100.01 Elektromagnetna združljivost Electromagnetic compatibility
na splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

95/646/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60255-26/AMD1 ED4
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-09-04 2026-11-27
SUPERSEDES DOCUMENTS:
95/600/CD, 95/606/CC
IEC TC 95 : MEASURING RELAYS AND PROTECTION EQUIPMENT
SECRETARIAT: SECRETARY:
France Mr Thierry BARDOU
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 14,TC 17,TC 38,TC 77,TC 115,TC 122
ASPECTS CONCERNED:
Electricity transmission and distribution,Electromagnetic Compatibility
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Amendment 1 - Measuring relays and protection equipment - Part 26: Electromagnetic
compatibility requirements
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
•
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
Committee positions. You may not copy or "mirror" the file or printed version of the document, o r any part of it, for
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IEC CDV 60255-26/AMD1 © IEC 2026
1 INTERNATIONAL ELECTROTECHNICAL COMMISSION
2 ____________
4 MEASURING RELAYS AND PROTECTION EQUIPMENT –
6 Part 26: Electromagnetic compatibility requirements
8 AMENDMENT 1
10 FOREWORD
11 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
12 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
13 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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19 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
20 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
21 consensus of opinion on the relevant subjects since each technical committee has representation from all
22 interested IEC National Committees.
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27 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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30 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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37 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
38 Publications.
39 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
40 indispensable for the correct application of this publication.
41 9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
42 patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
43 respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
44 may be required to implement this document. However, implementers are cautioned that this may not represent
45 the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
46 shall not be held responsible for identifying any or all such patent rights.
47 Amendment 1 to IEC 60255-26:2023 has been prepared by subcommittee MT2:
48 electromagnetic Compatibility (EMC) Requirements for Measuring Relays and Protection
49 Equipment, of IEC technical committee 95: Measuring relays and protection equipment.
50 The text of this Amendment is based on the following documents:
Draft Report on voting
XX/XX/XXXX XX/XX/XXX
52 Full information on the voting for its approval can be found in the report on voting indicated in
53 the above table.
IEC CDV 60255-26/AMD1 © IEC 2026
54 The language used for the development of this Amendment is English.
55 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
56 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
57 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
58 described in greater detail at www.iec.ch/publications/.
59 The committee has decided that the contents of this document will remain unchanged until the
60 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
61 specific document. At this date, the document will be
62 • reconfirmed,
63 • withdrawn, or
64 • revised.
IEC CDV 60255-26/AMD1 © IEC 2026
69 3  Terms and definitions
70 3.1.23
71 Replace the Figure by the following
75 Add the following new definitions:
76 3.1.28
77 DC power output port
78 output port of a DC power supply interface to energize auxiliary equipment. The DC power
79 output port is not used for communicating with auxiliary equipment.
80 3.1.29
81 Analogue input signal port
82 input signal whose value is directly proportional to measured physical quantity with a maximum
83 voltage of less than 50 V and a maximum current of less than 100 mA. (e.g. RTD, 20 mA
84 interface)
85 [SOURCE: IEC 60050-447:2020-05, 447-03-19, modified – “with a maximum voltage of less than 50 V and a maximum
86 current of less than 100 mA. (e.g. RTD, 20 mA interface)” has been added to the definition]
87 3.1.30
88 Pick-up signal
89 output signal that asserts when a measuring relay or protection equipment starts (picks up)
90 [SOURCE: IEC 60050-447:2020-05, 447-04-13]
91 Note 1: Start signal (pick-up signal), among all output signals, can be dedicated or not.
IEC CDV 60255-26/AMD1 © IEC 2026
94 5.2  Conducted emission
95 Add the following text before Table 3
96 No conducted emission requirements apply to DC power output ports in conjunction with CISPR
97 H standards
99 5.1  Radiated emission
100 Replace table 1 with the following new table
101 - Radiated emission limit (above 1 GHz) has been corrected in item 1.2 based on CISPR 32:2015/AMD1:2019
103 Table 1 – Radiated emission tests – Enclosure port
Reference Test
standard procedure
Environmental
Item Frequency range Limits (reference to
phenomena
this
document)
40 dB (µV/m) quasi­peak
at 10 m
30 MHz to 230 MHz
50 dB (µV/m) quasi­peak
Radiated
at 3 m
emission
1.1 CISPR 11 See 7.2.2
a
47 dB (µV/m) quasi­peak
(below 1 GHz)
at 10 m
230 MHz to 1 000 MHz
57 dB (µV/m) quasi­peak
at 3 m
60 dB (µV/m) average
Radiated
at 3 m
1.2 emission 1 GHz to 6 GHz CISPR 32 See 7.2.2
80 dB (µV/m) peak
(above 1 GHz)
at 3 m
a
Measuring relays and protection equipment are apparatus which satisfy the class A limits. Limits can be
measured at a nominal distance of 3 m or 10 m or 30 m. A measuring distance less than 10 m is allowed only
for equipment which complies with the definition for "small equipment" given in 3.1.26. In the case of
measurements at a separation distance of 30 m, an inverse proportionality factor of 20 dB per decade shall be
used to normalize the measured data to the specified distance for determining compliance.
At the transition frequency, the more stringent limit shall apply.
107 6.3  Immunity of signal/control port and wired network port
108 Replace table 7 with the following new table
109 - source impedance is removed from the item 7.4 to prevent inconsistencies with the application of the EMC
110 basic standard.
IEC CDV 60255-26/AMD1 © IEC 2026
111 Table 7 – Immunity tests – signal/control port and wired network port
Item Environmental Test Units Basic EMC Test Acceptance
phenomena specification publication procedure criteria
(see 8.2)
7.1 Conducted disturbance
induced by radio-
frequency fields
Frequency sweep
Test frequency range 0,15 to 80 MHz
Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
IEC
Frequency step size ≤ 1 % (of preceding
See 7.3.7 A
61000-4-6
frequency value)
Spot frequencies
Test spot frequencies 27 ± 0,135 MHz

Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
7.2 Electrical fast
transient/burst
Rise time t /    5 / 50 ns
r
Pulse duration t
d
IEC
Test level
See 7.3.4 B
61000­4­4
Zone A 4 kV (peak voltage)
Zone B 2 kV (peak voltage)
Repetition frequency 5 kHz
Source impedance 50 Ω
7.3 Damped oscillatory
waves
Voltage oscillation 1 MHz
frequency
Test level
Common mode 1 kV (peak voltage)
IEC
See 7.3.5 B
61000-4-18
Zone A
Voltage oscillation 3/10/30 MHz
frequency
Test level
Common mode 2 kV (peak voltage)

IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
7.4 Surge
Front time / 1,2/50 (8/20) µs voltage (current)
Time to half value
Test level
Line-to-Line
IEC
See 7.3.6 B
Zone A 0,5 1 2  kV 61000-4-5
Zone B 0,5 1   kV
Line-to-earth
Zone A 0,5 1 2 4 kV
Zone B 0,5 1 2  kV
IEC CDV 60255-26/AMD1 © IEC 2026
115 Replace the title of clause 6.4 by the following one
117 6.4 Immunity of input, output and DC power output port
118 Replace table 8 with the following new table
119 - Title of the table is updated.
120 - Coupling resistor and coupling capacitor are removed from Item 8.4 for line-to-line and line-to-earth tests
121 to prevent inconsistencies with the application of the EMC basic standard.
122 - Note b is updated
123 Table 8 – Immunity tests – Input, output and DC power output port
Item Environmental Test Units Basic EMC Test Acceptance
phenomena specification publication procedure criteria
(see 8.2)
8.1 Conducted disturbance
induced by radio-
frequency fields
Frequency sweep
Test frequency range 0,15 to 80 MHz
Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
IEC
Frequency step size ≤ 1 % (of preceding
See 7.3.7 A
61000-4-6
frequency value)
Spot frequencies
Test spot frequencies 27 ± 0,135 MHz

Test level (prior to 10 V (RMS)
modulation)
Source impedance 150 Ω
Amplitude 80 % AM (1 kHz)
modulated
8.2 Electrical fast
transient/burst
Rise time t /    5 / 50 ns
r
Pulse duration t
d
IEC
Test level
See 7.3.4 B
61000-4-4
Zone A 4 kV (peak voltage)
Zone B 2 kV (peak voltage)
Repetition frequency 5 kHz
Source impedance 50 Ω
IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
8.3 Damped oscillatory
waves
Voltage oscillation 1 MHz
frequency
Test level
a
1 kV (peak voltage)
Differential mode
Common mode 2,5 kV (peak voltage)
IEC
See 7.3.5 B
61000-4-18
Zone A
Voltage oscillation
3/10/30 MHz
frequency
Test level
Common mode 2 kV (peak voltage)

b
8.4
Surge
Front time / 1,2/50 (8/20) µs voltage (current)
Time to half value
Test level
Line-to-line
IEC
See 7.3.6 B
Zone A 0,5 1 2 kV 61000-4-5
Zone B 0,5 1 kV
Line-to-earth
Zone A 0,5 1 2 4 kV
Zone B 0,5 1 2 kV
c
8.5
Power frequency
Zone A
Test voltage 150 V (RMS)
Differential mode
Coupling resistor 100 Ω
Coupling capacitor 0,1 µF
Test voltage 300 V (RMS)
Common mode
Coupling resistor 220 Ω
IEC
See 7.3.8 A
Coupling capacitor 0,47 µF
61000-4-16
Zone B
Test voltage 100 V (RMS)
Differential mode
Coupling resistor 100 Ω
Coupling capacitor 0,047 µF
Test voltage 300 V (RMS)
Common mode
Coupling resistor 220 Ω
Coupling capacitor 0,47 µF
IEC CDV 60255-26/AMD1 © IEC 2026
Environmental Test Basic EMC Test Acceptance
Item Units
phenomena specification publication procedure criteria
(see 8.2)
a
In more severe environments a differential test voltage of 2,5 kV may be required for current and voltage
transformer inputs.
b
Shielded ports (e.g. Low-power current transformer (LPCT) and low-power voltage transformer (LPVT) input
ports) shall be tested in accordance with IEC 61000-4-5:2014, 7.6. and unshielded ports shall be tested in
accordance with IEC 61000-4-5:2014, 7.4 or 7.5.
c
The power frequency test is only applicable to binary input ports that register only DC or both AC and DC
voltages. Binary input ports that can register only AC voltages are excluded from this test. Dual rated AC and
DC input may have AC or DC mode selection based on hardware or software settings; in that case the test shall
be done with selection in DC mode only. See Annex A for specification of generator and CDN and Annex B for
background information for power frequency tests.
125 6.5  Immunity of earth port
126 Replace in Table 9 the existing note at the bottom by the following:
127 Multiple earth ports shall be tested separately.
IEC CDV 60255-26/AMD1 © IEC 2026
131 7.3.2  Electrostatic discharge immunity test
132 Replace Table 12 with the following new table
133 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
134 Table 12 – Electrostatic discharge immunity test
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
The EUT is placed in its case or housing in as close to
Details of mounting and support
installed conditions as possible.
Tests on the enclosure shall be applied as follows:
– the contact discharge method is the preferred method;
– the air discharge method shall only be used when the
Discharge method accessible surfaces of the EUT are non-conducting;
– the direct and indirect application test method shall be
used.
For test set-up of different applications, see IEC 61000­4-2.
The points selected for the application of the test shall be
those which are accessible to the operator under normal
operating conditions, including communication ports and
Application of the discharges
those points for setting adjustments that can only be
accessed by removing a cover.
See furthermore IEC 61000-4-2:2008, Table 4
Test voltage See Table 5, item 5.2.
The relay shall be energized as given under EUT
configuration and the relay settings shall comply with
7.3.1.6.
Since the coincidence of electrostatic discharges and a
primary fault is considered to be unlikely, the effect of the
electrostatic discharges on the EUT in its transitional or
operate condition is not considered.
Setting adjustments which necessitate any action other than
removal of the cover, such as removal of a module, are not
included.
The application of discharge to any point of the equipment
which is accessible only for repair and maintenance
Test application
purposes is outside the scope of this document. In the
selection of test points, tests shall be carried out on the
following:
– knobs, push-buttons, switches, communication interfaces,
etc., accessible under normal service;
– points on covers of insulating material where conducting
parts are close to the inside of the cover;
– points on conducting parts not belonging to, but placed in
the vicinity of, the EUT, when this has an insulating cover.
The selected test points shall be recorded in the test report.
Testing shall be carried out at all levels given in Table 5,
item 5.2.
Basic EMC publication IEC 61000-4-2
Acceptance criteria See Table 5, item 5.2.
IEC CDV 60255-26/AMD1 © IEC 2026
138 7.3.3  Radiated electromagnetic field immunity test
139 Replace Table 13 with the following new table
140 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
141 Table 13 – Radiated electromagnetic field immunity test (frequency sweep)
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Details of mounting and support The EUT is placed in the calibrated UFA.
Frequency range to be swept See Table 5, item 5.1.
RF Modulation 80 % AM (1 kHz)
The dwell time of the amplitude modulated carrier at each
frequency shall not be less than the time necessary for the
Dwell time
EUT to be exercised and to respond, but shall in no case be
less than 0,5 s.
Test field strength See Table 5, item 5.1.
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
All other ports of the relay shall remain in their initial
Test application
condition. The tests shall be performed on the front, back,
left and right side of the EUT. Additional tests are required
for sides with ventilation slots or all 6 sides if the enclosure
is non-metallic. This shall be evaluated during a risk
assessment.
Basic EMC publication IEC 61000-4-3
Acceptance criteria See Table 5, item 5.1.
IEC CDV 60255-26/AMD1 © IEC 2026
145 Replace Table 14 with the following new table
146 - Item “EUT configuration”, the indication “(AC or DC)” is added in the test procedure
147 Table 14 – Radiated electromagnetic field immunity test (spot frequencies)
Test set-up Test procedure
Auxiliary power supply ports: lowest rated value (AC or DC)
EUT configuration
All other ports: test reference conditions (see 7.3.1.2)
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Details of mounting and support The EUT is placed in the calibrated UFA.
Spot frequencies See Table 5, item 5.1.
RF Modulation 80 % AM (1 kHz)
Test duration ≥ 10 s
The dwell time at each spot frequency shall be sufficient for
Dwell time the EUT to change from the test reference condition to the
operate state.
Test field strength See Table 5, item 5.1.
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
During each spot frequency test, the input energizing
quantities shall be adjusted to cause the EUT to change
from the test reference conditions to the operated state and
held until the EUT operates correctly. The input energizing
quantities shall then be re-adjusted to cause the EUT to go
Test application
back to test reference conditions.
Background information on the spot frequency test can be
found in Annex C.
The tests shall be performed on the front, back, left and
right side of the EUT. Additional tests are required for sides
with ventilation slots or for all 6 sides if the enclosure is
non-metallic. This shall be evaluated during a risk
assessment.
Basic EMC publication IEC 61000-4-3
Acceptance criteria See Table 5, item 5.1.
IEC CDV 60255-26/AMD1 © IEC 2026
150 7.3.4  Electrical fast transient/burst immunity test
151 Replace Table 15 with the following new table
152 - Item “EUT configuration”, in the “Test procedure” column,
153 o Test Case 1: the indication “(AC or DC)” is added
154 o Test case 2: the indication “(AC and DC)” is added
155 - Item “Coupling method”, the DC power output port is added.
rd
156 - Item “Test application”, in the column “Test procedure”, 3 paragraph, the term “functional” is suppressed
157 and the text becomes “For the earth port, the fast transient/burst test is not…”
158 Table 15 – Electrical fast transient/burst immunity test
Test set-up Test procedure
Test case 1:
Auxiliary power supply ports: lowest rated value (AC or DC)
All other ports: test reference conditions (see 7.3.1.2)
Test case 2:
EUT configuration
Auxiliary power supply ports: highest rated value (AC and
DC)
All other ports: test reference conditions (see 7.3.1.2)
For test case 2 only auxiliary power supply ports and the
battery monitor ports need to be subjected to the test.
Initial measurement The tests shall be carried out in accordance with 7.3.1.
Where the EUT is mounted in a cabinet, the tests may be
conducted on the EUT mounted in that particular cabinet. No
Details of mounting/support
test shall be performed on interconnecting cables within the
same cabinet.
Coupling methods
Auxiliary power supply ports CM with CDN
AC current and voltage input ports CM with CDN
LPIT input ports CM with CCC
Earth port CM with CDN
DC power output ports CM with CDN
Input ports CM with CCC
Output ports CM with CCC
Signal/control ports and wired network ports CM with CCC
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Test voltage
Table 9, item 9.2.
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Repetition frequency
Table 9, item 9.2.
See Table 6, item 6.2; Table 7, item 7.2; Table 8, item 8.2;
Test wave form characteristic
Table 9, item 9.2
IEC CDV 60255-26/AMD1 © IEC 2026
Test set-up Test procedure
The relay shall be energized as given under EUT
configuration (first row of this table) and the relay settings
shall comply with 7.3.1.6.
All auxiliary equipment used to provide the EUT with signal
for normal operation, and to verify the correct operation of
the EUT, shall be decoupled.
For the earth port, the fast transient/burst test is not
applicable to this
...