⚡ Assessment of voltage changes, voltage fluctuations and flicker produced by equipment with rated current from 16 A to 75 A (and equipment within the scope of IEC 61000-3-3 not meeting its limits) in public low-voltage systems of 220–250 V, 50 Hz — measurement at a test impedance Ztest (dc drop 2–9 %, X/R 0,5–0,75), conversion to Zref, limits Pst ≤ 1,0, Plt ≤ 0,65, dc ≤ 3,3 %, dmax 4/6/7 %, Tmax ≤ 500 ms; determination of the maximum permissible system impedance Zmax or a test for a service capacity ≥ 100 A per phase, PN-EN IEC 61000-3-11

Electronics and EMC PN-EN IEC 61000-3-11

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN IEC 61000-3-11:2020-01 (English version; scope in Polish on the card) — the first sentences (our translation): “This part of IEC 61000 is concerned with the emission of voltage changes, voltage fluctuations and flicker produced by equipment and impressed on the public low-voltage supply system. The standard specifies the limits of voltage changes produced by equipment tested under specified conditions. This document is primarily applicable to electrical and electronic equipment having a rated input current from 16 A up to and including 75 A, which is intended to be connected to public low-voltage distribution systems having nominal voltages of between 220 V and 250 V, line-to-neutral, at 50 Hz, and which is subject to conditional connection”; the card then quotes the sentence on equipment within the scope of IEC 61000-3-3, type tests and both notes of Clause 1. We read the text in the sample of IEC 61000-3-11:2017 (edition 2.0) from the cover to the end of 6.4 and in the sample of SIST EN IEC 61000-3-11:2019 (European foreword and Annex ZA); we do not have the informative Annexes A (flicker exponents with multiple items of equipment) and B (flow chart, reference network with Figure B.2) — we know only their titles from the table of contents.

ACCORDING TO THE TEXT OF IEC 61000-3-11:2017 (foreword, introduction, Clauses 1–6.4, table of contents). The standard was prepared by subcommittee SC 77A (EMC — low-frequency phenomena) of IEC TC 77; the second edition replaces the first of 2000 after technical revision; significant change: a new Annex A explaining the limitations and effectiveness of the standard when multiple items of similar equipment are connected at the same location in the network. Foreword of EN IEC 61000-3-11:2019: IEC text approved without modification, date of national implementation (dop) 2020-05-01, date of withdrawal of conflicting standards (dow) 2022-11-01; the sentence on the superseded standard reads in the sample “supersedes EN 61300-3-11:2000” — as in the text. Scope (1): emission of voltage changes, voltage fluctuations and flicker impressed on the public low-voltage system; limits of voltage changes for equipment tested under specified conditions; primarily equipment with rated input current from 16 A up to and including 75 A, for systems of 220–250 V line-to-neutral, 50 Hz, subject to conditional connection; also equipment within the scope of IEC 61000-3-3 that does not meet its limits at Zref; equipment meeting IEC 61000-3-3 is excluded; tests according to this standard are type tests. Note 1: the flicker limits — the same as in IEC 61000-3-3 — are based on the subjective severity of flicker of 230 V/60 W coiled-coil filament lamps; limits for systems below 220 V or at 60 Hz are under consideration. Note 2: the limits relate to the interface between the public network and the user’s installation and do not guarantee the absence of disturbance within that installation. References (2): IEC 60050-161, IEC TR 60725, IEC 61000-3-3:2013. Terms (3): reference impedance Zref (from IEC 61000-3-3, value according to IEC TR 60725, components in Figure B.2); interface point; conditional connection — requiring the supply impedance at the interface point to be lower than Zref (meeting the voltage change limits is not the only connection condition, e.g. harmonics); service current capacity — in practice the rating of the main service fuse or the setting of the circuit breaker at the interface point, and where capacity is given in VA: for single phase VA divided by the phase voltage, for three phases — by √3 times the line voltage. Requirements (4): assessment by the methods of IEC 61000-3-3; equipment above 16 A meeting IEC 61000-3-3 may be declared so by the manufacturer in documentation available before purchase; equipment not meeting its limits at Zref is subject to conditional connection, and the manufacturer shall: a) determine according to 6.3 the maximum permissible system impedance Zmax at the interface point, declare it in the instruction manual and instruct the user to determine (if necessary with the supply authority) that the supply impedance is not higher, or b) test the equipment according to 6.4 and declare that it is intended only for premises with a service current capacity of at least 100 A per phase from a 400/230 V network, marking it clearly (note 2: symbol IEC 60417-5855). Limits (5) at the supply terminals of the equipment under test: a) Pst not greater than 1,0; b) Plt not greater than 0,65; c) Tmax — the accumulated time during which d(t) exceeds 3,3 % during a voltage change — not longer than 500 ms; d) dc not greater than 3,3 %; e) dmax: 4 % without additional conditions; 6 % for equipment switched manually or automatically more than twice per day, with delayed (at least a few tens of seconds) or manual restart after a power supply interruption (note: a rectangular dmax of 6 % twice per hour gives a Plt of about 0,65); 7 % for equipment attended while in use (e.g. milling machines, lathes) or switched on no more than twice per day with delayed or manual restart; for equipment with multiple subsystems the 6 % and 7 % limits apply only with delayed or manual restart; Pst and Plt do not apply to voltage changes from manual switching; the limits do not apply to emergency switching or interruptions. Procedures (6): general conditions, measurement and evaluation according to IEC 61000-3-3 (for equipment up to 16 A — its Annex A); modulus values of complex impedances in calculations; suffixes sys, ref, act, max, test (Table 1). The test impedance Ztest (6.2.1) may be lower than Zref, but the steady-state voltage drop dc caused by the equipment shall be within 2–9 % of the test supply voltage and the ratio Xtest/Rtest within 0,5–0,75; test in the circuit of Figure B.2 with Ztest instead of Zref, measuring dc test, dmax test, Pst test and Plt test (6.2.2); with Ztest different from Zref the values are multiplied by Zref/Ztest, and if the conditions for dc and dmax are met, Tmax is deemed satisfied (6.2.3). If all values are within the limits of Clause 5, the manufacturer may declare that the product meets the technical requirements of IEC 61000-3-3 (6.3.1); otherwise (6.3.2) Zsys1 = Zref · (dmax limit appropriate to the equipment / dmax), Zsys2 = Zref · (3,3 % / dc), Zsys3 = Zref · (1 / Pst)^(3/2), Zsys4 = Zref · (0,65 / Plt)^(3/2) are calculated; the smallest of the four is Zmax (with manual switching only Zsys1 and Zsys2 are calculated); if dmax exceeds 3,3 % and no recording of d(t) is available, additional tests for Tmax are required. Test for a service of at least 100 A per phase (6.4): single-phase equipment 230 V — Ztest = 0,25 + j0,25 Ω; three-phase 400 V — 0,15 + j0,15 Ω per line and 0,1 + j0,1 Ω in the neutral; the equipment shall meet the limits of Clause 5.

STATUS (PKN catalogue cards as of 02.10.2026). The card of PN-EN IEC 61000-3-11:2020-01 (English version, published 27-01-2020, 28 pages, price group N) has no “Withdrawn” heading: Information and Communication Technologies Sector, KT 104 Electromagnetic Compatibility, ICS 33.100.10, “Introduces: EN IEC 61000-3-11:2019 [IDT], IEC 61000-3-11:2017 [IDT]”, “Replaces: PN-EN 61000-3-11:2004 – Polish version”. The card of PN-EN 61000-3-11:2004 (Polish version) has the “Withdrawn” heading: withdrawal date 27-01-2020, “Replaced by: PN-EN IEC 61000-3-11:2020-01”; it itself replaced PN-EN 61000-3-11:2002 (English version).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 02.10.2026). The number 61000-3-11 appears in 14 records at 7 laboratories: AB 082 (7), AB 261 (2), AB 167, AB 171, AB 666, AB 1132, AB 1925 (1 each). In the current scopes on the PCA website (read 02.10.2026, issues from 10.07.2025 to 04.08.2026) the 2020-01 edition written as “PN-EN IEC 61000-3-11:2020-01” is given by AB 261, AB 666 and AB 1925, written without “IEC” — by AB 1132 (“PN-EN 61000-3-11:2020”) and by AB 167 and AB 171, which also have the withdrawn 2004 edition next to it; AB 082 gives the withdrawn 2002 edition for the vehicle items (UN Regulation No 10, Annexes 12 and 18), and in one item also the 2020-01 edition. In the scope of AB 171 (issue No 21 of 13.05.2026) the part of the scope marked in bold italics was suspended at the request of the body — the lines with PN-EN 61000-3-11 are not marked so. The “Laboratories” tab searches for entries STARTING WITH “PN-EN IEC 61000-3-11” and shows 4 laboratories (AB 082, AB 261, AB 666, AB 1925); AB 167, AB 171 and AB 1132 have entries starting with “PN-EN 61000-3-11” or with the number PN-EN 61000-3-3, so they do not appear in this tab — checked with the tab query on the production server labcoda.pl on 02.10.2026.

WHAT THE LABORATORIES TEST (PCA entries). Voltage fluctuations and flicker together with PN-EN 61000-3-3: electrical and electronic equipment with phase supply current up to 75 A (AB 167), electrical and electronic equipment (AB 171, AB 261 — also with PN-EN 61000-4-15), electrical and telecommunication products and equipment (AB 1132), industrial, scientific and medical equipment and appliances for general use (AB 1925), household appliances — “measurement method: direct” (AB 666); vehicles of categories M, N, O, L, T and their sub-assemblies as well as equipment and vehicles with AC cables — emission of voltage changes according to UN Regulation No 10 (AB 082).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Test impedance: Ztest may be lower than Zref only when two conditions are met — dc drop of 2–9 % and X/R of 0,5–0,75 (6.2.1); only then may the results be converted proportionally by Zref/Ztest (6.2.3). Evaluation: the result “meets IEC 61000-3-3” (6.3.1) and the declaration of Zmax (6.3.2) are two different conclusions — Zmax is the smallest of the four impedances Zsys, and with manual switching — of two. dmax limit: whether 4, 6 or 7 % depends on the switching and on the restart after a supply interruption; for equipment with multiple subsystems 6 % and 7 % only with delayed or manual restart (5 e). Tmax: if dmax exceeds 3,3 % and there is no recording of d(t), additional tests are needed (6.3.2). Edition: AB 082 for the vehicle items and AB 167 and AB 171 next to the 2020-01 edition cite withdrawn editions (2002, 2004).

WHAT WE DO NOT STATE. We do not have Annexes A and B: the explanation of flicker exponents with multiple items of equipment, the flow chart of Figure B.1 or the component values of the reference impedance from Figure B.2 — so we do not state the value of Zref; the definitions of dc, dmax, Pst and Plt and the measurement methods are in IEC 61000-3-3 (a separate entry), not in this standard.

Method principle

The equipment is tested by the methods of IEC 61000-3-3 at a test impedance Ztest (dc drop 2–9 %, X/R 0,5–0,75), dc, dmax, Pst and Plt are measured, converted to the reference impedance Zref by the ratio Zref/Ztest and compared with the limits; if exceeded, four impedances Zsys are calculated, the smallest being the maximum permissible system impedance Zmax declared by the manufacturer (or the equipment is tested at the impedance of a service of at least 100 A per phase).

Applications

• Electrical and electronic equipment with rated current of 16–75 A and equipment not meeting IEC 61000-3-3 at Zref — 7 laboratories in PCA scopes
• Vehicles and their sub-assemblies with AC cables — emission of voltage changes according to UN Regulation No 10
• Manufacturer declarations: compliance with the technical requirements of IEC 61000-3-3, maximum system impedance Zmax or minimum service current capacity of 100 A per phase

Key parameters

Standard

Standard number

PN-EN IEC 61000-3-11:2020-01 (wersja angielska; EN IEC 61000-3-11:2019 IDT, IEC 61000-3-11:2017 IDT)

Title (PL)

Kompatybilność elektromagnetyczna (EMC) — Część 3-11: Poziomy dopuszczalne — Ograniczanie zmian napięcia, wahań napięcia i migotania światła w publicznych sieciach zasilających niskiego napięcia — Urządzenia o prądzie znamionowym < lub = 75 A podlegające przyłączeniu warunkowemu

Title (EN)

Electromagnetic compatibility (EMC) — Part 3-11: Limits — Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems — Equipment with rated current ≤75 A and subject to conditional connection

Step-by-step procedure

1. Qualification of the equipment

   Equipment of 16–75 A or within the scope of IEC 61000-3-3 not meeting its limits at Zref; the test is a type test. PN-EN IEC 61000-3-11:2020-01 current (PKN cards as of 02.10.2026).

2. Choice of Ztest

   Steady-state drop dc within 2–9 % of the test supply voltage, Xtest/Rtest 0,5–0,75.

3. Measurement

   Circuit of Figure B.2 with Ztest instead of Zref; measurement of dc test, dmax test, Pst test and Plt test by the methods of IEC 61000-3-3.

4. Conversion to Zref

   Each value is multiplied by Zref/Ztest; with dc and dmax met, Tmax is deemed satisfied.

5. Evaluation and declaration

   All values within the limits of Clause 5 — declaration of compliance with the technical requirements of IEC 61000-3-3; otherwise Zmax = the smallest of Zsys1–Zsys4 (with manual switching of Zsys1 and Zsys2) or a test at the impedance of a service ≥ 100 A per phase (6.4).

Required equipment and apparatus

Health and safety (OHS)

• The standard contains no safety warnings in the part we read; the test involves work at mains voltage — the laboratory sets the electrical safety rules
• TECHNICAL NOTE: the limits refer to the interface with the public network and do not guarantee the absence of disturbance within the user’s installation (Clause 1, Note 2)

Frequently asked questions