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

• Status: Not Published
• Public Enquiry End Date: 19-Nov-2026
• ICS: 29.120.70 - Relays
• ICS: 33.100.01 - Electromagnetic compatibility in general
• Technical Committee: ISS EIT.ERE - All-or-nothing electrical relays
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 09-Sep-2026
• Due Date: 27-Jan-2027
• Ref Project: EN IEC 60255-26:2025/prA1:2026 - Amendment 1 - Measuring relays and protection equipment - Part 26: Electromagnetic compatibility requirements

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

SIST EN IEC 60255-26:2025/FprA1:2026 is the Slovenian adoption of Amendment 1 to IEC 60255-26:2023 for measuring relays and protection equipment. It updates the electromagnetic compatibility (EMC) requirements for this equipment, including emission limits, immunity test methods, port-specific test conditions, and acceptance criteria used by manufacturers and test laboratories.

What does SIST EN IEC 60255-26:2025/FprA1:2026 specify?

SIST EN IEC 60255-26:2025/FprA1:2026 specifies amendments to the EMC requirements for measuring relays and protection equipment. The document is organized into terms and definitions, emission requirements, immunity tests, acceptance criteria, and annexes that support specific test methods.

The amendment keeps the structure of the base part and updates several test tables so that the requirements match additional port types and revised EMC practice.

Annex	What it covers
Annex A	Power frequency immunity tests on binary inputs
Annex B	Background information for power frequency tests
Annex C	Background information for the spot frequency test

Clause 3 covers terms and definitions. Clauses 5 and 6 cover emission and immunity requirements. Clause 7 gives the detailed immunity test procedures, and Clause 8 gives the acceptance criteria.

What are the key requirements of SIST EN IEC 60255-26:2025/FprA1:2026?

SIST EN IEC 60255-26:2025/FprA1:2026 focuses on how measuring relays and protection equipment are tested for EMC at their different ports. The practical point is that the exact interface under test matters: auxiliary power, input, output, signal/control, wired network, earth, and DC power output ports are not treated the same way.

Emission requirements

Clause 5.1 updates the radiated emission table for enclosure ports. Measuring relays and protection equipment are treated as apparatus that meet class A limits, and the table distinguishes measurements below 1 GHz from those above 1 GHz using CISPR 11 and CISPR 32. This matters because the test distance, measurement method, and reported level all affect whether the equipment passes.

Clause 5.1 also allows measurement at 3 m, 10 m, or 30 m, with special rules for smaller equipment and for normalizing 30 m results. At the transition frequency, the stricter limit applies. In practice, the laboratory must use the correct distance and normalize the data properly before deciding compliance.

Clause 5.2 adds a specific note for conducted emission: no conducted emission requirements apply to DC power output ports in conjunction with CISPR H standards. That means these ports are not checked in the same way as the other conducted-emission interfaces.

Immunity by port type

Clauses 6.3 and 6.4 split immunity tests by port category. Clause 6.3 covers signal/control ports and wired network ports, while Clause 6.4 covers input, output, and DC power output ports. The update adds DC power output ports to the immunity tables and clarifies how analogue input signal ports are handled. This is important because the port type determines the coupling method, the disturbance level, and the acceptance criteria.

Clause 6.4 also states that the power frequency test applies only to binary input ports that register DC or both AC and DC voltages. Binary input ports that register only AC voltages are excluded from that test. Where an input can work in either AC or DC mode, the test is done in DC mode only. Annex A gives the generator and CDN specification, and Annex B gives background information for the power frequency tests.

Detailed immunity tests

Clauses 7.3.2 to 7.3.12 define the detailed test procedures. The amendment updates electrostatic discharge, radiated electromagnetic field immunity, electrical fast transient/burst, damped oscillatory wave, surge, conducted RF immunity, power frequency magnetic field immunity, voltage dips and short interruptions, ripple on DC input power, and gradual shutdown/start-up testing.

These clauses matter because they tell the test lab how to mount the equipment, which surfaces or ports to stress, which coupling devices to use, how long to apply the disturbance, and when the test is not applicable. For example, Clause 7.3.2 requires discharge testing on accessible enclosure points and asks the tester to record the selected points in the report. Clause 7.3.7 requires auxiliary equipment to be decoupled and gives separate procedures for frequency sweep and spot frequency tests.

Acceptance criteria

Clause 8.2 updates the acceptance criteria table for immunity tests. Protection functions must stay within specification limits, including pick-up signals, during and after the test. Command and control functions also have to stay within specification limits. Other functions, such as measurement, analogue output port, DC power output port, human-machine interface, data communication, and binary input or output ports, may have different levels of temporary degradation depending on the criterion applied.

In practice, this means the test result is not just pass or fail in one general sense. The acceptable behavior depends on the function being checked and on whether the equipment is tested to criterion A, B, or C.

Annex A detail

Annex A, which covers power frequency immunity tests on binary inputs, clarifies that when several identical circuits exist, at least 10% of the circuits are tested. It also updates Figure A.3. That is useful for planning a representative test sample without testing every identical circuit.

What terms does SIST EN IEC 60255-26:2025/FprA1:2026 define?

• Equipment under test (EUT) - the relay or protection equipment placed in the EMC test setup and exercised during the disturbance.
• Coupling and decoupling network (CDN) - the device used to inject disturbances into a port while isolating the test object from unwanted effects on the supply or line.
• Direct current power output port - an output port of a DC power supply interface used to energize auxiliary equipment, not to communicate with it.
• Analogue input signal port - an input whose value is directly proportional to the measured physical quantity, with maximum voltage below 50 V and maximum current below 100 mA.
• Pick-up signal - an output signal that asserts when a measuring relay or protection equipment starts.
• Common mode (CM) - the coupling mode used in several immunity tests where the disturbance is applied relative to a common reference path.
• Capacitive coupling clamp (CCC) - the coupling method used for some signal, input, and output port tests.

Who uses SIST EN IEC 60255-26:2025/FprA1:2026?

SIST EN IEC 60255-26:2025/FprA1:2026 is used by manufacturers of measuring relays and protection equipment, EMC test laboratories, and conformity assessment teams. It is also relevant to quality managers, buyers, and utility engineers who specify or verify protection equipment for electricity transmission and distribution systems.

In practice, users apply it when they design ports, choose test setups, prepare product documentation, run EMC qualification tests, and review acceptance criteria for protection, command and control, measurement, communication, and alarm functions.

What changed in SIST EN IEC 60255-26:2025/FprA1:2026 from the previous edition?

SIST EN IEC 60255-26:2025/FprA1:2026 is Amendment 1 to IEC 60255-26:2023. The amendment introduces these main changes:

• adds definitions for DC power output port, analogue input signal port, and pick-up signal
• replaces the figure in 3.1.23
• states that no conducted emission requirements apply to DC power output ports with CISPR H standards
• corrects the radiated emission limit above 1 GHz in Table 1
• updates the immunity tables to include DC power output ports and analogue input signal ports
• revises the test application notes for ESD, radiated RF, EFT, damped oscillatory waves, surge, conducted RF, power frequency magnetic field, voltage dips and short interruptions, ripple on DC input power, and gradual shutdown/start-up
• updates the acceptance criteria so they explicitly cover pick-up signals and DC power output ports
• revises Annex A, including the sample-circuit rule and Figure A.3

Which standards are used with SIST EN IEC 60255-26:2025/FprA1:2026?

SIST EN IEC 60255-26:2025/FprA1:2026 relies on a set of EMC basic standards and emission standards for the individual test methods.

• 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 on AC supply
• IEC 61000-4-16 - power frequency disturbance immunity used for some port tests
• IEC 61000-4-17 - ripple on DC input power port
• IEC 61000-4-18 - damped oscillatory wave immunity
• IEC 61000-4-29 - additional voltage dip or interruption testing used with Clause 7.3.10
• CISPR 11 - radiated emission limits below 1 GHz
• CISPR 32 - radiated emission limits above 1 GHz
• IEC 60050-447:2020-05 - source for the modified definition of analogue input signal port

What does the SIST EN IEC 60255-26:2025/FprA1:2026 document contain?

The document contains updated emission tables, immunity tables, and acceptance criteria tables for EMC testing of measuring relays and protection equipment. It also contains detailed test setups for enclosure ports, signal and control ports, input and output ports, earth ports, and DC power output ports.

It gives test conditions such as coupling methods, dwell times, disturbance levels, port applicability, and the use of CDNs, clamps, and other test arrangements. These details are used for design verification, type testing, certification work, and test reporting.

Annex A provides the power frequency immunity test arrangement for binary inputs, including the generator and CDN example. Annex C provides background information for the spot frequency conducted RF test, which helps the tester understand how to apply the spot-frequency method in practice.

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
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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
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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.
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 t
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