EN IEC 60691:2023/A2:2026
(Amendment)Thermal-links - Requirements and application guide
- Status
- Published
- Publication Date
- 17-Sep-2026
- Technical Committee
- CLC/SR 32C - Miniature fuses
- Current Stage
- 6060 - Document made available - Publishing
- Start Date
- 18-Sep-2026
- Due Date
- 26-Jan-2026
- Completion Date
- 18-Sep-2026
EN IEC 60691:2023/A2:2026 is a CLC amendment to the thermal-links standard EN IEC 60691. It updates the requirements and application guide for thermal-links, with the shown changes focused on Annex I and the holding-temperature test procedure. It is intended for manufacturers, test laboratories, and others who assess thermal-links used as safety protection devices.
What does EN IEC 60691:2023/A2:2026 specify?
EN IEC 60691:2023/A2:2026 updates the thermal-links requirements and application guide by revising Annex I, which is informative and covers holding temperature. The amendment concentrates on how to apply that annex, how to set up the test, and how to judge the result.
| Annex | What it covers |
|---|---|
| Annex I | Holding temperature, including the test setup and compliance check |
In practice, this means the amendment is mainly about test execution and interpretation. If you qualify or verify thermal-links, Annex I tells you when the procedure applies, how to run it, and what outcome counts as acceptable.
What are the key requirements of EN IEC 60691:2023/A2:2026?
The most important points in EN IEC 60691:2023/A2:2026 are the revised instructions for Annex I. Clause I.11.2 and its subclauses define the test conditions for holding temperature, especially for group K specimens.
Annex I applicability
Annex I is applicable when the manufacturer declares it, and the amendment states that it is required in Germany. For a buyer, maker, or test lab, that means the document links the test directly to declared product information and to country-specific application.
Measuring the oven temperature
Clause I.11.2 requires the static-air oven temperature to be measured as close as possible to the center of the space occupied by the test fixture assembly, at about 50 mm from the assembly. Fine-wire thermocouples or equivalent means are used, with minimal effect on the temperature being measured. In practice, the measurement method must not disturb the test.
Temperature uniformity and stabilization
The oven conditions must stay within tight limits in the test area: ±1 K at nominal temperatures up to 200 °C, or ±0.5% above 200 °C. Clause I.11.2.2 says the oven is stable when two readings taken 5 minutes apart are within 1 K. This gives the test lab a clear rule for when it can start timing the test.
Test fixture and connection method
Clause I.11.2.1 says the wire size, wire type, or termination method used to connect the thermal-link to the electrical load shall not significantly affect the thermal-link temperature. The setup must avoid a heatsink effect. In practice, the fixture must represent the product test without artificially cooling the thermal-link.
Group K specimen arrangement
Clause I.11.2.3 requires three group K specimens to be secured to a test fixture assembly, mounted so they are not in direct contact and are electrically isolated from the oven walls. The amendment also allows the three specimens to be tested individually. For the tester, the key point is to prevent thermal interference between specimens and the oven.
Energizing and acceptance
Clause I.11.2.4 places the fixture with the three specimens in a stabilized oven at the Th temperature declared by the manufacturer, then energizes the thermal-links with the resistive rated current for 24 hours or for the manufacturer-declared period, whichever is higher. Clause I.11.2.5 then requires a continuity check after the test; the thermal-link shall not change its state of conductivity. That is the pass/fail basis.
Packaged assemblies
Clause I.11.2.6 points to Annex H for requirements for thermal-link packaged assemblies. This tells users that packaged assemblies are handled under additional guidance elsewhere in the standard.
What terms does EN IEC 60691:2023/A2:2026 define?
Thermal-link - A safety device that changes state when a temperature condition is reached.
Holding temperature (Th) - The temperature declared by the manufacturer for the thermal-link test in Annex I.
Static-air oven - The test oven used to create the controlled temperature environment for the holding-temperature procedure.
Test fixture assembly - The arrangement that holds the specimens during the oven test and connects them to the electrical load.
Group K - The specimen group named in Annex I for this holding-temperature procedure.
Resistive rated current - The current used to energize the thermal-links during the test, as specified in Annex I.
State of conductivity - Whether the thermal-link still conducts or has changed state after the test.
Who uses EN IEC 60691:2023/A2:2026?
EN IEC 60691:2023/A2:2026 is used by manufacturers of thermal-links, test laboratories, certification and conformity assessment bodies, and quality or safety engineers. It is also relevant to buyers and technical teams who need to verify that thermal-links have been tested under the specified holding-temperature conditions. The amendment matters most in electrical safety work, especially where thermal-links are used as protective components in equipment.
What changed in EN IEC 60691:2023/A2:2026 from the previous edition?
This amendment revises Annex I, “Holding temperature.” It replaces the note on when Annex I applies, states that Annex I is required in Germany and otherwise applies when declared by the manufacturer, and clarifies the test instructions for temperature measurement, stability, specimen mounting, energizing time, and the continuity check. It also adds the pointer to Annex H for thermal-link packaged assemblies.
What does the EN IEC 60691:2023/A2:2026 document contain?
The document contains procedural test language for Annex I, including how to place the temperature sensor, how to judge oven stability, and how to mount the specimens. It also gives practical guidance to avoid fixture-induced cooling and recommends a large mass metal block to reduce temperature drop when the oven is opened. The core task supported by the amendment is thermal-link testing for design verification, product qualification, and safety assessment.
Relations
- Effective Date
- 13-May-2025
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Frequently Asked Questions
EN IEC 60691:2023/A2:2026 is a draft published by CLC. Its full title is "Thermal-links - Requirements and application guide". This standard covers: Thermal-links - Requirements and application guide
Thermal-links - Requirements and application guide
EN IEC 60691:2023/A2:2026 is classified under the following ICS (International Classification for Standards) categories: 29.120.50 - Fuses and other overcurrent protection devices. The ICS classification helps identify the subject area and facilitates finding related standards.
EN IEC 60691:2023/A2:2026 has the following relationships with other standards: It is inter standard links to EN IEC 60691:2023. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN IEC 60691:2023/A2:2026 is associated with the following European legislation: EU Directives/Regulations: 2014/35/EU; Standardization Mandates: M/511. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN IEC 60691:2023/A2:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN IEC 60691:2024/oprA2:2025
01-september-2025
Termični taljivi vložki - Zahteve in navodilo za uporabo - Dopolnilo 2
Thermal-links - Requirements and application guide
Temperatursicherungen - Anforderungen und Anwendungshinweise
Protecteurs thermiques - Exigences et guide d'application
Ta slovenski standard je istoveten z: EN IEC 60691:2023/prA2:2025
ICS:
29.120.50 Varovalke in druga Fuses and other overcurrent
nadtokovna zaščita protection devices
SIST EN IEC 60691:2024/oprA2:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
SIST EN IEC 60691:2024/oprA2:2025
SIST EN IEC 60691:2024/oprA2:2025
32C/661/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60691/AMD2 ED5
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2025-06-27 2025-09-19
SUPERSEDES DOCUMENTS:
32C/660/RR
IEC SC 32C : MINIATURE FUSES
SECRETARIAT: SECRETARY:
China Mr Jun Cai
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
ASPECTS CONCERNED:
Safety
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 2 - Thermal-links - Requirements and application guide
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
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
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SIST EN IEC 60691:2024/oprA2:2025
IEC CDV 60691/AMD2 © IEC 2025
1 Annex I
2 (informative)
...