What is the scope of IEC 61000-4-11?

IEC 61000-4-11 defines the immunity test methods and the range of preferred test levels for voltage dips, short interruptions and voltage variations on equipment with a rated input current not exceeding 16 A per phase, connected to 50 Hz or 60 Hz AC networks. It does not apply to 400 Hz networks. Above 16 A per phase, IEC 61000-4-34 applies. The current edition is 3.0, published on 28 January 2020, which replaced the 2004 edition and its 2017 amendment. It is a basic EMC publication: product committees decide whether the test applies and which levels to use.

Which test levels does IEC 61000-4-11 propose?

Table 1 gives preferred dip levels by environment class. Class 2 is 0 % for half a cycle, 0 % for 1 cycle and 70 % for 25/30 cycles. Class 3 adds 40 % for 10/12 cycles and 80 % for 250/300 cycles. Table 2 gives a short interruption of 0 % for 250/300 cycles for both classes. The first figure is the cycle count at 50 Hz, the second at 60 Hz, so 25/30 cycles is 500 ms on either supply. For equipment connected directly or indirectly to the public network, levels set by a product committee must not be less severe than Class 2.

Does the standard require dips at both 0 and 90 degrees?

No. IEC 61000-4-11 requires voltage changes for dips to occur at zero crossings, plus any additional angles that product committees or product specifications consider critical, preferably chosen from 45, 90, 135, 180, 225, 270 and 315 degrees on each phase. For short interruptions the product committee defines the worst-case angle; without a definition, 0 degrees on one of the phases is recommended. The generic standards EN 61000-6-1 and EN 61000-6-2 specify the voltage shift at zero crossing.

How many dips are applied for each test level?

Each selected combination of level and duration is applied as a sequence of three dips or interruptions with at least 10 s between test events, and each representative operating mode is tested. On a three-phase supply with neutral, each phase-to-neutral and phase-to-phase voltage is tested one at a time (six series); without neutral, the three phase-to-phase voltages (three series). Short interruptions on three-phase systems are applied to all three phases simultaneously.

Which generic standard levels give presumption of conformity in the EU?

The EMC Directive list cites EN 61000-6-1:2007 and EN 61000-6-2:2005, not the 2019 editions. Their AC power port tables call for 0 % for half a cycle and 1 cycle (criterion B) plus 70 % for 25/30 cycles (criterion C) in residential and light-industrial environments, and 0 % for 1 cycle (B), 40 % for 10/12 cycles (C) and 70 % for 25/30 cycles (C) in industrial environments. Both add a 0 % interruption for 250/300 cycles at criterion C.

Where do performance criteria A, B and C come from?

Not from IEC 61000-4-11. The test method only recommends a four-step classification of results, from normal performance to non-recoverable loss of function. Generic and product standards turn that into acceptance criteria, for example criterion B or C for dips in EN 61000-6-1 and EN 61000-6-2. IEC 60601-1-2 does not use A, B, C at all: it assesses basic safety and essential performance with pass/fail criteria the manufacturer identifies.

Is IEC 61000-4-39 about long-duration interruptions?

No. IEC 61000-4-39:2017 covers immunity to radiated fields in close proximity, such as transmitters held near the equipment. Dips and interruptions on DC input ports are covered by IEC 61000-4-29, whose second edition was published on 30 July 2026, and voltage fluctuations by IEC 61000-4-14.

Voltage dips and interruptions (IEC 61000-4-11)

Hugues Orgitello updated 7 Oct 2026 12 min read

IEC 61000-4-11 is the basic EMC publication for immunity to voltage dips, short interruptions and voltage variations on AC mains, for equipment drawing no more than 16 A per phase from a 50 Hz or 60 Hz network. Edition 3.0 was published on 28 January 2020 by subcommittee 77A of IEC TC 77, and its two corrigenda (May 2020 and October 2022) are included in the current copy. The standard offers preferred levels by environment class, but product committees choose which ones apply. This page lays out the test levels cell by cell, the generator specification, the procedure, the levels actually required by the generic standards cited in the EU, and the claims that circulate about this test that the texts contradict.

Editions and companion standards, dated

Publication	Edition	Date	Status on 7 October 2026
IEC 61000-4-11	2.0	24 March 2004	Withdrawn 28 January 2020 (amended in 2017 by AMD1)
IEC 61000-4-11	3.0	28 January 2020	Current; corrigenda May 2020 and October 2022; stability date 2028
IEC 61000-4-34	1.0	17 October 2005	Current, with AMD1:2009 and AMD2:2025 (consolidated 1.2 dated 7 August 2025)
IEC 61000-4-29	1.0	30 August 2000	Withdrawn 30 July 2026
IEC 61000-4-29	2.0	30 July 2026	Current
IEC 61000-4-39	1.0	9 March 2017	Current; not a dips standard (radiated fields in close proximity)

The 2020 edition of 4-11 lists only two significant technical changes against 2004 + AMD1:2017: rise time and fall time became defined terms in Clause 3, and the origin of dips and short interruptions is now stated in Clause 4. The test levels, the procedure and the generator requirements quoted below come from the 2004 text, which is freely readable as the identical Indian adoption IS 14700 (Part 4/Sec 11):2008; the change list of the 2020 edition does not touch them.

Position in the IEC 61000-4 series

Reference	Phenomenon
IEC 61000-4-2	Electrostatic discharge (ESD)
IEC 61000-4-3	Radiated radio-frequency electromagnetic field
IEC 61000-4-4	Electrical fast transient bursts (EFT/Burst)
IEC 61000-4-5	Surge
IEC 61000-4-6	Conducted disturbances induced by RF fields
IEC 61000-4-8	Power-frequency magnetic field
IEC 61000-4-11	Dips, short interruptions, voltage variations, AC, up to 16 A per phase
IEC 61000-4-14	Voltage fluctuations (referred to by 4-11 NOTE 1)
IEC 61000-4-29	Dips, short interruptions, voltage variations on DC input power ports
IEC 61000-4-34	Dips, short interruptions, voltage variations, AC, above 16 A per phase
IEC 61000-4-39	Radiated fields in close proximity

The only normative reference of 4-11 is IEC TR 61000-2-8, which reports statistical measurements of dips and short interruptions on public supply networks. The standard says its preferred levels take that report into account, are "reasonably severe" and representative of many real-world dips, but are not intended to guarantee immunity to all dips. It names more severe cases, such as 0 % for 1 s and balanced three-phase dips, that product committees may add.

4-11 (up to 16 A) or 4-34 (above 16 A)

Point	IEC 61000-4-11	IEC 61000-4-34
Rated input current	Not exceeding 16 A per phase	Exceeding 16 A per phase
Networks	50 Hz or 60 Hz AC; not 400 Hz	50 Hz or 60 Hz AC, single-phase and three-phase mains
Current edition	3.0 (2020)	1.0 (2005) + AMD1:2009 + AMD2:2025
Status	Basic EMC publication (IEC Guide 107)	Basic EMC publication (IEC Guide 107)

Both define the method and a range of preferred levels; neither decides whether the test applies to a given product. That is the job of the product committee, as NOTE 2 of the 4-11 scope states.

Preferred test levels, cell by cell

Levels are expressed as residual voltage in % of the rated voltage U_T: a 70 % dip leaves 70 % of U_T on the terminals. A level between 0 % and 20 % may be treated as a total interruption. "25/30 cycles" means 25 cycles for a 50 Hz test and 30 cycles for a 60 Hz test.

Disturbance (Tables 1 and 2)	Class 2	Class 3	Duration at 50 Hz	Duration at 60 Hz
Dip, 0 % for ½ cycle	Yes	Yes	10 ms	about 8.3 ms
Dip, 0 % for 1 cycle	Yes	Yes	20 ms	about 16.7 ms
Dip, 40 % for 10/12 cycles	No	Yes	200 ms	200 ms
Dip, 70 % for 25/30 cycles	Yes	Yes	500 ms	500 ms
Dip, 80 % for 250/300 cycles	No	Yes	5 s	5 s
Short interruption, 0 % for 250/300 cycles	Yes	Yes	5 s	5 s

Class 1 is "case by case according to the equipment requirements" and Class X is defined by the product committee. Footnote b of both tables sets a floor: for equipment connected directly or indirectly to the public network, the levels must not be less severe than Class 2. The classes follow IEC 61000-2-4 (Annex B of 4-11).

The 80 % row is a dip lasting 250/300 cycles in Class 3, not an "optional light" level, and the 40 % row exists only in Class 3. For products with a mains transformer, the standard warns that a half-cycle dip can cause inrush currents of 10 to 40 times the rated current through core saturation when the voltage returns.

Voltage variations (Table 3)

Test level	Time to decrease (t_d)	Time at reduced voltage (t_s)	Time to increase (t_i)
70 %	Abrupt	1 cycle	25/30 cycles
X	X	X	X

The rate of change should be constant, but the voltage may be stepped at zero crossings in steps no larger than 10 % of U_T. The 2004 edition labelled this test "optional"; in the 2020 table of contents, clause 8.3.3 is simply "Voltage variations". Either way, the product standard decides whether it is applied.

Generator specification (Table 4)

Parameter	Requirement
Output voltage at no load	As required in Table 1, ±5 % of the residual voltage value
Voltage change with load (0 A to 16 A at 100 %, 20 A at 80 %, 23 A at 70 %, 40 A at 40 %)	Less than 5 % of U_T
Output current	16 A r.m.s. per phase at rated voltage; 20 A at 80 % for 5 s; 23 A at 70 % and 40 A at 40 % for 3 s (may be reduced per Clause A.3)
Peak inrush current capability	Not limited by the generator, but need not exceed 1 000 A (250 V to 600 V mains), 500 A (220 V to 240 V), 250 A (100 V to 120 V); not required for variation tests
Overshoot or undershoot, 100 Ω resistive load	Less than 5 % of U_T
Rise and fall time during abrupt change, 100 Ω load	Between 1 µs and 5 µs

The 1 µs to 5 µs edge rules out a manually adjusted transformer or a slow programmable source for the abrupt dip test. Annex D of the 2020 edition explains the rationale for fast fall times and for the inrush current capability.

Test procedure (clause 8)

Rated voltage range: if the declared range does not exceed 20 % of its lower value, a single voltage in the range may be used as U_T; otherwise the test is run at both the lowest and the highest declared voltage.
Repetition: each selected level and duration is applied as three dips or interruptions, at least 10 s apart. Each representative mode of operation is tested.
Phase angle, dips: changes occur at zero crossings, plus additional angles the product committee or product specification considers critical, preferably from 45°, 90°, 135°, 180°, 225°, 270° and 315° on each phase.
Phase angle, short interruptions: defined by the product committee as the worst case; without a definition, 0° on one of the phases is recommended.
Three-phase: with neutral, each phase-to-neutral and phase-to-phase voltage is dipped one at a time (six series); without neutral, the three phase-to-phase voltages (three series). Short interruptions are applied to all three phases simultaneously.
Several power cords: each cord should be tested individually.
Monitoring: the mains voltage is monitored within 2 % during the tests.
Voltage variations: each specified variation is applied three times at 10 s intervals in the most representative modes.

Evaluating results

4-11 does not set pass criteria. Clause 9 recommends classifying results as: (a) normal performance within specified limits; (b) temporary loss of function or degradation that ceases after the disturbance, with recovery without operator intervention; (c) temporary loss of function or degradation requiring operator intervention; (d) loss of function not recoverable because of hardware or software damage or data loss. Generic and product standards turn this into criteria A, B and C. IEC 60601-1-2 works differently: it assesses basic safety and essential performance, and Annex I of the 2020 consolidated edition gives guidance on identifying immunity pass/fail criteria.

What the EU-cited generic standards require

Under the EMC Directive 2014/30/EU, presumption of conformity comes from the references in the Official Journal: the 2018 Communication (OJ C 246, 13 July 2018) read together with Implementing Decision (EU) 2019/1326 and its five amendments up to 9 June 2022. IEC 61000-4-11 itself is not in that list: it is called up by the product and generic standards that are.

Reference cited for the EMC Directive	Status	Dips and interruptions on AC mains
EN 61000-6-1:2007 (IEC 61000-6-1:2005), residential, commercial, light industry	Cited; the 2019 edition is not	0 % ½ cycle (B), 0 % 1 cycle (B), 70 % 25/30 cycles (C), interruption 0 % 250/300 cycles (C)
EN 61000-6-2:2005 + AC:2005 (IEC 61000-6-2:2005), industrial	Cited; the 2019 edition is not	0 % 1 cycle (B), 40 % 10/12 cycles (C), 70 % 25/30 cycles (C), interruption 0 % 250/300 cycles (C)
EN 55035:2017 + A11:2020, multimedia	Cited (Decision (EU) 2021/455)	Clause 4.2.6 "Voltage dips and interruptions"; read the levels in the standard
EN 55024:2010, information technology	Withdrawn from the list on 16 September 2022	Replaced by EN 55035
EN 61326-1:2013, measurement, control and laboratory	Cited	Read the dip levels in the standard

In both generic tables the dips apply only to input ports and the voltage shift is at zero crossing. EN 61000-6-2 adds that, for electronic power converters, operation of protective devices is allowed. EN 60601-1-2 is not in the EMC Directive list, and it is not in the medical devices list either (Decision (EU) 2021/1182, consolidated on 17 June 2026).

IEC 61000-4-29 for DC input ports

IEC 61000-4-29 applies the same three phenomena to DC input power ports connected to low-voltage DC networks external to the equipment. Ripple is excluded (it belongs to IEC 61000-4-17). Edition 2.0, published on 30 July 2026, raises the generator output voltage for new DC network voltages, adds tolerances on the duration of voltage changes, limits the current when short interruptions are applied in low-impedance condition, clarifies generator verification and test reports, and describes the DC environment. Note that the generic standards above test a product with an external AC/DC adaptor on the AC input of the adaptor.

IEC 61000-4-34 above 16 A

IEC 61000-4-34 covers the same phenomena for equipment above 16 A per phase, residential and industrial, single-phase and three-phase. It gives separate figures for acceptable and non-acceptable methods of phase-to-phase testing on three-phase systems. Its second amendment dates from 2025.

Claims the texts contradict

Common claim (including on earlier versions of this page)	What the text says
IEC 61000-4-39 covers resilience to long-duration interruptions	IEC 61000-4-39:2017 is "Radiated fields in close proximity, Immunity test"
The standard requires dips at both 0° and 90°	4-11 requires zero crossing; other angles are added only where the product committee or specification says so. EN 61000-6-1 and -6-2 specify zero crossing
The dip grid is 5/6, 10/12, 25/30 and 50/60 cycles at 0 %, 40 % and 70 %	Tables 1 and 2 hold ½ and 1 cycle at 0 %, 10/12 cycles at 40 %, 25/30 cycles at 70 %, 250/300 cycles at 80 % (dip) and at 0 % (interruption)
80 % is an optional light level found only in some product standards	80 % for 250/300 cycles is a Class 3 preferred dip in 4-11 itself
25 cycles at 60 Hz is a valid 500 ms dip	25/30 means 25 cycles at 50 Hz and 30 cycles at 60 Hz; both are 500 ms
EN 61000-6-1:2019 and EN 61000-6-2:2019 give presumption of conformity	The EMC list cites EN 61000-6-1:2007 and EN 61000-6-2:2005
EN 55024 is still a valid route for IT equipment	EN 55024:2010 left the list on 16 September 2022
EN 60601-1-2 4th edition introduced a combined "B + C" criterion	IEC 60601-1-2 assesses basic safety and essential performance with manufacturer-identified pass/fail criteria, not A, B, C
Criteria A, B, C are fixed by IEC 61000-4-11	4-11 only recommends a four-step classification (a to d); acceptance criteria come from the product or generic standard
A test at 0 % lasting 250/300 cycles is "5000 ms at 50 Hz and about 5000 ms at 60 Hz" by approximation	250 cycles at 50 Hz and 300 cycles at 60 Hz are both exactly 5 s

Pitfalls observed in test plans

Wrong cycle count at 60 Hz. Programming 25 cycles on a 60 Hz supply gives about 417 ms instead of 500 ms. The report must state the test frequency and the cycle count used.
Product standard not pinned. The method gives a menu; the cited product or generic standard selects the rows. EN 61000-6-1 and EN 61000-6-2 do not ask for the same dips, and neither asks for the Class 3 80 % dip.
Rated voltage range ignored. A product declared 100 V to 240 V exceeds the 20 % rule, so the test runs at both ends of the range.
Generator not verified. Rise and fall times of 1 µs to 5 µs and the inrush capability are part of the requirement; the report identifies the test equipment.
Operating modes. The standard asks for each representative mode of operation, so a standby mode that the product spends time in is part of the plan.
Confusion with surge. Surge (IEC 61000-4-5) is an impulse; a dip is a reduction of the r.m.s. voltage over half a cycle to several seconds. See Surge and Burst IEC 61000-4-5 / 4-4.

Connection with CE marking and the EMC Directive

For the broader CE EMC test context, see the CE tests page, the CE standards page and the RED tests page which applies to radio equipment.

For the definitions of the terms used on this page (dip, interruption, residual voltage, criterion A/B/C, EUT, power port), see the glossary. The equipment under test is abbreviated EUT.

Going further

The transient immunity tests that sit alongside 4-11 have their own page: 4-5 surge and 4-4 burst.

Not covered in depth on this site, and worth going to the standards themselves for: the 4-34 levels and three-phase vector methods above 16 A, and the 2026 edition of 4-29 for DC ports.

Sources & references

IEC 61000-4-11:2020 (Edition 3.0), voltage dips, short interruptions and voltage variations immunity tests up to 16 A per phase, IEC webstore.iec.ch/en/publication/66487
IEC 61000-4-11:2004 (Edition 2.0) record, withdrawn 28 January 2020, edition history, IEC webstore.iec.ch/publication/4162
IS 14700 (Part 4/Sec 11):2008, identical to IEC 61000-4-11:2004, full text (Tables 1 to 4, clauses 8 and 9), Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.4.11.2008.pdf
IEC 61000-4-34:2005+AMD1:2009+AMD2:2025 CSV, equipment with mains current more than 16 A per phase, IEC webstore.iec.ch/en/publication/109082
IEC 61000-4-29:2026 (Edition 2.0), dips, short interruptions and voltage variations on DC input power ports, IEC webstore.iec.ch/en/publication/115498
IEC 61000-4-39:2017, radiated fields in close proximity, immunity test, IEC webstore.iec.ch/en/publication/30202
IS 14700 (Part 6/Sec 1):2008, identical to IEC 61000-6-1:2005, Table 4 AC power ports, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.1.2008.pdf
IS 14700 (Part 6/Sec 2):2008, identical to IEC 61000-6-2:2005, Table 4 AC power ports, Bureau of Indian Standards (via Public.Resource.Org) law.resource.org/pub/in/bis/S04/is.14700.6.2.2008.pdf
Commission Implementing Decision (EU) 2019/1326, harmonised standards for EMC, consolidated text of 10 June 2022, Publications Office of the European Union publications.europa.eu/resource/celex/02019D1326-20220610
Harmonised standards for electromagnetic compatibility, decisions and summary list, European Commission single-market-economy.ec.europa.eu/single-market/goods/european-standards/harmonised-standards/electromagnetic-compatibility-emc_en
Commission Implementing Decision (EU) 2021/1182, harmonised standards for medical devices, consolidated text of 17 June 2026, Publications Office of the European Union publications.europa.eu/resource/celex/02021D1182-20260617
CISPR 35:2016, electromagnetic compatibility of multimedia equipment, immunity requirements, IEC webstore.iec.ch/en/publication/25667
IEC 60601-1-2:2014+AMD1:2020 CSV, medical electrical equipment, electromagnetic disturbances, IEC webstore.iec.ch/en/publication/67554
IEC TC 77 Electromagnetic compatibility, IEC www.iec.ch/dyn/www/f?p=103:7:::::FSP_ORG_ID:1303

Frequently asked questions

What is the scope of IEC 61000-4-11?: IEC 61000-4-11 defines the immunity test methods and the range of preferred test levels for voltage dips, short interruptions and voltage variations on equipment with a rated input current not exceeding 16 A per phase, connected to 50 Hz or 60 Hz AC networks. It does not apply to 400 Hz networks. Above 16 A per phase, IEC 61000-4-34 applies. The current edition is 3.0, published on 28 January 2020, which replaced the 2004 edition and its 2017 amendment. It is a basic EMC publication: product committees decide whether the test applies and which levels to use.
Which test levels does IEC 61000-4-11 propose?: Table 1 gives preferred dip levels by environment class. Class 2 is 0 % for half a cycle, 0 % for 1 cycle and 70 % for 25/30 cycles. Class 3 adds 40 % for 10/12 cycles and 80 % for 250/300 cycles. Table 2 gives a short interruption of 0 % for 250/300 cycles for both classes. The first figure is the cycle count at 50 Hz, the second at 60 Hz, so 25/30 cycles is 500 ms on either supply. For equipment connected directly or indirectly to the public network, levels set by a product committee must not be less severe than Class 2.
Does the standard require dips at both 0 and 90 degrees?: No. IEC 61000-4-11 requires voltage changes for dips to occur at zero crossings, plus any additional angles that product committees or product specifications consider critical, preferably chosen from 45, 90, 135, 180, 225, 270 and 315 degrees on each phase. For short interruptions the product committee defines the worst-case angle; without a definition, 0 degrees on one of the phases is recommended. The generic standards EN 61000-6-1 and EN 61000-6-2 specify the voltage shift at zero crossing.
How many dips are applied for each test level?: Each selected combination of level and duration is applied as a sequence of three dips or interruptions with at least 10 s between test events, and each representative operating mode is tested. On a three-phase supply with neutral, each phase-to-neutral and phase-to-phase voltage is tested one at a time (six series); without neutral, the three phase-to-phase voltages (three series). Short interruptions on three-phase systems are applied to all three phases simultaneously.
Which generic standard levels give presumption of conformity in the EU?: The EMC Directive list cites EN 61000-6-1:2007 and EN 61000-6-2:2005, not the 2019 editions. Their AC power port tables call for 0 % for half a cycle and 1 cycle (criterion B) plus 70 % for 25/30 cycles (criterion C) in residential and light-industrial environments, and 0 % for 1 cycle (B), 40 % for 10/12 cycles (C) and 70 % for 25/30 cycles (C) in industrial environments. Both add a 0 % interruption for 250/300 cycles at criterion C.
Where do performance criteria A, B and C come from?: Not from IEC 61000-4-11. The test method only recommends a four-step classification of results, from normal performance to non-recoverable loss of function. Generic and product standards turn that into acceptance criteria, for example criterion B or C for dips in EN 61000-6-1 and EN 61000-6-2. IEC 60601-1-2 does not use A, B, C at all: it assesses basic safety and essential performance with pass/fail criteria the manufacturer identifies.
Is IEC 61000-4-39 about long-duration interruptions?: No. IEC 61000-4-39:2017 covers immunity to radiated fields in close proximity, such as transmitters held near the equipment. Dips and interruptions on DC input ports are covered by IEC 61000-4-29, whose second edition was published on 30 July 2026, and voltage fluctuations by IEC 61000-4-14.