EN IEC 61051-2:2021/prA1:2026

• Status: Not Published
• Publication Date: 09-Jan-2028
• ICS: 31.040.20 - Potentiometers, variable resistors
• Technical Committee: CLC/SR 40 - Capacitors and resistors for electronic equipment
• Current Stage: 4060 - Enquiry results established and sent to TC, SR, BTTF - Enquiry
• Start Date: 11-Sep-2026
• Completion Date: 11-Sep-2026
• Ref Project: SIST EN IEC 61051-2:2022/oprA1:2026 - Amendment 1 - Varistors for use in electronic equipment - Part 2: Sectional specification for surge suppression varistors

• Amends: EN IEC 61051-2:2021 - Varistors for use in electronic equipment - Part 2: Sectional specification for surge suppression varistors
• Effective Date: 14-Mar-2023

Overview

EN IEC 61051-2:2021/prA1:2026 is Amendment 1 to the international standard specifying varistors for use in electronic equipment, focusing on the sectional specification for surge suppression varistors. Developed by the International Electrotechnical Commission (IEC) and adopted by CENELEC (CLC), this amendment refines testing schedules, inspection procedures, and clarifies requirements for quality conformance and periodic inspections of varistors. Varistors play a critical role in protecting electronic circuits from transient voltage surges, making this standard important for manufacturers, testing labs, and designers in the electronics industry.

Key Topics

• Varistor Quality Assurance: The amendment details the necessary schedules and protocols for ensuring varistors consistently meet quality standards. It covers both lot-by-lot and periodic inspections.
• Testing Procedures: Comprehensive requirements are updated for visual examination, electrical tests, solderability, marking resistance to solvents, voltage proof, and mechanical robustness.
• Assessment Levels: The standard includes specific criteria and acceptance levels for assessment, including the calculation of quality levels and nonconforming units.
• Inspection Schedules: Amendment 1 introduces clear test groupings (A, B, C, and D) covering routine, lot-by-lot, and periodic inspections to cover all phases of production and lifecycle reliability.
• Marking and Identification: Requirements for legible and durable marking of varistors are highlighted, ensuring traceability and facilitating proper installation and replacement.

Applications

EN IEC 61051-2:2021/prA1:2026 is vital for several practical applications across the electronics sector:

• Electronic Equipment Protection: The standard ensures surge suppression varistors are properly tested and qualified, thereby safeguarding electronic devices and systems from voltage spikes.
• Product Development and Design: Engineers and designers integrate compliant varistors into consumer electronics, telecommunications, industrial automation, and computing devices for reliable overvoltage protection.
• Manufacturing and Quality Control: Factories and testing labs follow the specified inspection schedules to maintain high production quality, reduce failures, and ensure regulatory compliance.
• Procurement and Supply Chain: Buyers and sourcing professionals reference this standard to ensure the surge suppression varistors they source adhere to internationally recognized benchmarks.
• Component Testing Laboratories: Independent and in-house labs use the standard’s test criteria to verify product performance during periodic and type-testing.

Related Standards

To implement and reference EN IEC 61051-2:2021/prA1:2026 effectively, consider the following related standards:

• IEC 61051-2: The base standard for varistors used in electronic equipment, defining the general requirements, tests, and performance criteria.
• IEC 61193-2: Outlines test procedures and sampling plans for quality assessment of electronic components, referenced for inspection levels and quality conformance in this amendment.
• IEC 61051-1: General rules and definitions for varistors.
• IEC 61051-2-2 (Referenced as being withdrawn): Former blank detail specification for varistors.
• ISO/IEC Directives: General rules for the drafting and adoption of international standards in the electrotechnical domain.

EN IEC 61051-2:2021/prA1:2026 helps ensure the reliability, safety, and performance of surge suppression varistors in electronic equipment, supporting better product longevity and system integrity in line with international best practices for overvoltage protection.

SLOVENSKI STANDARD
01-september-2026
Varistorji za elektronsko opremo - 2. del: Področna specifikacija za varistorske
prenapetostne odvodnike - Dopolnilo A1
Amendment 1 - Varistors for use in electronic equipment - Part 2: Sectional specification
for surge suppression varistors
Varistoren zur Verwendung in Geräten der Elektronik – Teil 2: Rahmenspezifikation für
Varistoren für den Überspannungsschutz
Varistances utilisées dans les équipements électroniques - Partie 2: Spécification
intermédiaire pour varistances pour limitations de surtensions transitoires
Ta slovenski standard je istoveten z: EN IEC 61051-2:2021/prA1:2026
ICS:
31.040.20 Potenciometri, spremenljivi Potentiometers, variable
upori resistors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

40/3311/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61051-2/AMD1 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-06-19 2026-09-11
SUPERSEDES DOCUMENTS:
40/3249/CD, 40/3287/CC
IEC TC 40 : CAPACITORS AND RESISTORS FOR ELECTRONIC EQUIPMENT
SECRETARIAT: SECRETARY:
Netherlands Mr Ronald Drenthen
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):

ASPECTS CONCERNED:
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 - Varistors for use in electronic equipment - Part 2: Sectional specification for surge
suppression varistors
PROPOSED STABILITY DATE: 2031
NOTE FROM TC/SC OFFICERS:
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, or any part of it, for any other purpose
without permission in writing from IEC.

IEC CDV 61051-2 /AMD1 ED2 © IEC 2026
1 INTERNATIONAL ELECTROTECHNICAL COMMISSION
2 ____________
4 VARISTORS FOR USE IN ELECTRONIC EQUIPMENT –
6 Part 2: Sectional specification for surge suppression varistors
8 AMENDMENT 1
10 FOREWORD
11 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all
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36 publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
37 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
38 indispensable for the correct application of this publication.
39 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights.
40 IEC shall not be held responsible for identifying any or all such patent rights.
41 This amendment to IEC 61051-2 has been prepared by IEC technical committee 40: Capacitors and
42 resistors for electronic equipment.
43 The text of this Amendment is based on the following documents:
Draft Report on voting
XX/XX/FDIS XX/XX/RVD
45 Full information on the voting for its approval can be found in the report on voting indicated in the
46 above table.
47 The language used for the development of this International Standard is English.
48 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
49 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available at
IEC CDV 61051-2 /AMD1 ED2 © IEC 2026
50 www.iec.ch/members_experts/refdocs. The main document types developed by IEC are described in
51 greater detail at www.iec.ch/publications.
52 The committee has decided that the contents of this document will remain unchanged until the stability
53 date indicated on the IEC website under webstore.iec.ch in the data related to the specific document.
54 At this date, the document will be
55 • reconfirmed,
56 • withdrawn,
57 • replaced by a revised edition, or
58 • amended.
IEC CDV 61051-2 /AMD1 ED2 © IEC 2026
61 VARISTORS FOR USE IN ELECTRONIC EQUIPMENT –
63 Part 2: Sectional specification for surge suppression varistors
65 AMENDMENT 1
68 7.1 General
69 [In 7.1 reference to the relevant blank detail specification shall be deleted, because the blank ´detail
70 specification IEC 61051-2-2 will be withdrawn.]
71 Dele
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