⚡ Immunity to voltage dips, short interruptions and supply voltage variations — levels of 0 %, 40 % and 70 % of the rated voltage
In short
Equipment supplied from the low-voltage network is subjected to dips to 0 %, 40 % and 70 % of the rated voltage, with a duration from half a cycle to 50 cycles of the mains. The test is performed according to PN-EN IEC 61000-4-11:2020-11; Condition of applicability: Equipment with a rated input current of up to 16 A per phase, connected to 50 Hz or 60 Hz networks; 400 Hz networks outside the scope. The procedure comprises 8 steps (about 0 min in total); it is used for: Immunity testing of equipment supplied from the low-voltage network against supply interruptions and dips, Assessment of the behaviour of switched-mode power supplies, controllers and drives during short interruptions, Testing of protection systems and electromechanical devices, for which the 100 % level does not replace the intermediate levels.
At a glance
- Standard: PN-EN IEC 61000-4-11:2020-11
- Category: Electronics and EMC
- Procedure steps: 8
- Total time of stages: 0 min
- Condition of applicability: Equipment with a rated input current of up to 16 A per phase, connected to 50 Hz or 60 Hz networks; 400 Hz networks outside the scope
- Dip test levels: 0 % of the rated voltage (reduction of 100 %, short interruption), 40 % (reduction of 60 %), 70 % (reduction of 30 %)
- Durations: 0.5 cycle, 1, 5, 10, 25 and 50 mains cycles; duration "x" given in the technical requirements of the product
Overview
The standard defines the immunity test methods and the range of recommended test levels for electrical and electronic equipment connected to low-voltage supply networks, with regard to voltage dips, short interruptions and voltage variations. The document applies to electrical and electronic 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 equipment connected to 400 Hz networks — tests for such networks are to be covered by future IEC documents. Tests of immunity to voltage fluctuations are described separately in IEC 61000-4-14.
A voltage dip is described by two quantities: the test level expressed as a percentage of the rated voltage to which the voltage is reduced, and the duration expressed as a number of cycles of the mains voltage. The recommended levels are 0 % of the rated voltage, which corresponds to a reduction of 100 %, i.e. a short interruption, 40 % of the rated voltage with a reduction of 60 %, and 70 % with a reduction of 30 %. The recommended durations are 0.5 cycle, 1, 5, 10, 25 and 50 cycles, and also a duration "x" given in the technical requirements of the product. Each duration may be applied to each test level, and the selection of one or several levels and durations is permitted.
The standard notes that if the equipment is tested with dips of 100 %, there is in principle no need to test at other levels for the same durations, although this does not apply to certain cases, such as protection systems or electromechanical devices. As practical background the standard states that energy distributors in Europe have measured dips and short interruptions lasting from half a cycle to 3000 cycles, but durations shorter than 50 cycles are the most common.
SEARCH KEY CORRECTED (23.09.2026). The key field had the form "PN-EN IEC 61000-4-11", and the "Laboratories" tab searches by the beginning of the notation — as a result it showed 13 entries at 11 laboratories. In the accreditation scopes the same standard appears in two parallel forms, because the IEC element entered the number only with the newer edition: "PN-EN 61000-4-11" — 16 entries at 13 laboratories, "PN-EN IEC 61000-4-11" — 13 at 11; there are 5 laboratories in common, 19 in total (counted by the beginning of the notation, with a number boundary). The key has been set to the more numerous form; we give the other one here explicitly, because matching by the beginning of the notation does not cover both at once. HOW MANY LABORATORIES REMAIN OUTSIDE THE TAB: 6 laboratories use only the form with the IEC element for this standard, so no matching by the beginning of the notation will show them (the tab shows 13). THE COST OF CHOOSING ONE FORM DEPENDS ON THE BREADTH OF THE SUBJECT OF THE ENTRY: for an entry on the whole PN-EN 61000-4 series the key without the IEC element does not lose a single laboratory — all twelve using IEC also have notations without it for other parts of the series; for an entry on a single part from one to six are lost.
Method principle
The supply voltage of the equipment under test is reduced for a set time to a set level, expressed as a percentage of the rated voltage, and then restored. A voltage dip is characterised by two parameters: the level to which the voltage is reduced and the duration counted in cycles of the mains voltage. For a duration of 0.5 cycle the test is carried out at both polarities, i.e. starting at phase 0° and 180° respectively. The equipment under test is tested three times at intervals of 10 s, for the most representative operating modes. The generator or switching unit provides the set voltage accuracy, the accuracy being ±10 %. Supply voltage variations form a separate group, for which the standard gives its own table of recommended levels and durations.
Applications
- Immunity testing of equipment supplied from the low-voltage network against supply interruptions and dips
- Assessment of the behaviour of switched-mode power supplies, controllers and drives during short interruptions
- Testing of protection systems and electromechanical devices, for which the 100 % level does not replace the intermediate levels
- Compliance testing of products with the electromagnetic compatibility directive
- Testing of railway products, for which the immunity requirements of AC power ports refer to this standard
Key parameters
| Parameter | Value |
|---|---|
| Condition of applicability | Equipment with a rated input current of up to 16 A per phase, connected to 50 Hz or 60 Hz networks; 400 Hz networks outside the scope |
| Dip test levels | 0 % of the rated voltage (reduction of 100 %, short interruption), 40 % (reduction of 60 %), 70 % (reduction of 30 %) |
| Durations | 0.5 cycle, 1, 5, 10, 25 and 50 mains cycles; duration "x" given in the technical requirements of the product |
| Duration of 0.5 cycle | Test at both polarities — starting at phase 0° and at phase 180° |
| Number of tests | Three times at intervals of 10 s, for the most representative operating modes |
| Accuracy | ±10 % |
| Relationship of levels | Each duration may be applied to each level; the selection of one or several levels and durations is permitted |
| Practical background | Dips and interruptions measured in Europe lasted from half a cycle to 3000 cycles; durations shorter than 50 cycles are the most common |
| Supply voltage variations | Separate table of recommended test levels and durations in the standard |
Standard
- Standard number
- PN-EN IEC 61000-4-11:2020-11
- Title (PL)
- Kompatybilność elektromagnetyczna (EMC) — Część 4-11: Metody badań i pomiarów — Badania odporności na zapady napięcia, krótkie przerwy i zmiany napięcia
- Title (EN)
- Electromagnetic compatibility (EMC) — Part 4-11: Testing and measurement techniques — Voltage dips, short interruptions and voltage variations immunity tests
Step-by-step procedure
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Determining the scope of the test
Select test levels and durations from the recommended ones, taking into account the technical requirements of the product; the selection of one or several levels is permitted, and each duration may be applied to each level.
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Operating conditions of the equipment
Determine the most representative operating modes of the equipment under test, in which the dip is most significant for its operation.
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Setting up the test bench
Connect the equipment under test through the dip generator to a power supply with a current capacity sufficient for the inrush current, and connect the system monitoring the operation of the equipment.
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Checking the parameters
Verify the level and duration of the dip and the accuracy of ±10 %; check the correctness of the phase control of the switching unit.
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Test of dips with a duration of 0.5 cycle
Carry out the test at both polarities, starting the dip at phase 0° and at phase 180° respectively.
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Test of the remaining durations
Carry out dips with durations of 1, 5, 10, 25 and 50 cycles at the selected levels of 0 %, 40 % and 70 % of the rated voltage.
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Repetitions
Apply each test case three times at intervals of 10 s, observing the operation of the equipment under test during the dip and after the voltage is restored.
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Assessment and report
Assess the behaviour of the equipment according to the performance criteria from the product requirements. In the report state the levels, durations in cycles, phase angles, number of repetitions, operating modes of the equipment and the result.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Voltage dip generator | A unit capable of reducing the supply voltage to a set level for a set number of cycles, with an accuracy of ±10 % | — |
| Phase-controlled switching unit | Starting the dip at a set phase, including at 0° and 180° for a duration of 0.5 cycle | — |
| Power supply with sufficient current capacity | A source capable of covering the inrush current of the equipment under test when the voltage is restored | — |
| EUT operation monitoring equipment | Recording of the behaviour of the equipment during the dip and after the voltage is restored | — |
| Oscilloscope or voltage recorder | Verification of the level and duration of the dip in mains cycles | — |
Health and safety (OHS)
- The equipment under test remains at mains voltage — protection against electric shock at the test bench, emergency stop
- High inrush currents when the voltage is restored — selection of the power supply and protective devices, risk of overheating of the switching unit
- Sudden start-up of moving parts of the equipment under test after the supply is restored — safety zone around the test bench
- Repeated dips may damage the power supplies and drives of the equipment under test — observation of its condition between tests
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN IEC 61000-4-11:2020-11 — “Electromagnetic compatibility (EMC) — Part 4-11: Testing and measurement techniques — Voltage dips, short interruptions and voltage variations immunity tests”.
How does this method work?
The supply voltage of the equipment under test is reduced for a set time to a set level, expressed as a percentage of the rated voltage, and then restored. A voltage dip is characterised by two parameters: the level to which the voltage is reduced and the duration counted in cycles of the mains voltage.
What is the measuring range and accuracy?
Condition of applicability: Equipment with a rated input current of up to 16 A per phase, connected to 50 Hz or 60 Hz networks; 400 Hz networks outside the scope; Dip test levels: 0 % of the rated voltage (reduction of 100 %, short interruption), 40 % (reduction of 60 %), 70 % (reduction of 30 %); Durations: 0.5 cycle, 1, 5, 10, 25 and 50 mains cycles; duration "x" given in the technical requirements of the product; Duration of 0.5 cycle: Test at both polarities — starting at phase 0° and at phase 180°.
How long does the test take?
The times given for the individual stages add up to approximately 0 min. The procedure comprises 8 steps.
What equipment is required?
Voltage dip generator, Phase-controlled switching unit, Power supply with sufficient current capacity, EUT operation monitoring equipment, Oscilloscope or voltage recorder.
Where is this test used?
Immunity testing of equipment supplied from the low-voltage network against supply interruptions and dips; Assessment of the behaviour of switched-mode power supplies, controllers and drives during short interruptions; Testing of protection systems and electromechanical devices, for which the 100 % level does not replace the intermediate levels; Compliance testing of products with the electromagnetic compatibility directive; Testing of railway products, for which the immunity requirements of AC power ports refer to this standard.
What safety precautions apply?
The equipment under test remains at mains voltage — protection against electric shock at the test bench, emergency stop; High inrush currents when the voltage is restored — selection of the power supply and protective devices, risk of overheating of the switching unit; Sudden start-up of moving parts of the equipment under test after the supply is restored — safety zone around the test bench; Repeated dips may damage the power supplies and drives of the equipment under test — observation of its condition between tests.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 61000-4-11.