IEC TR 60943-2009 PDF

Full title and description

St IEC TR 60943-2009 — Guidance concerning the permissible temperature rise for parts of electrical equipment, in particular for terminals. This consolidated technical report (edition 2.1) combines the second edition (1998) with Amendment 1 (2008) and provides guidance for estimating allowable steady‑state temperatures and temperature rises of contacts, connection terminals and related conductive parts in electrical equipment.

Abstract

IEC/TR 60943:1998+A1:2009 supplies background theory and practical guidance on contact structure, calculation and measurement of ohmic/contact resistance, ageing mechanisms, calculation of temperature rise for contacts and terminals, recommended maximum permissible temperatures and rises for various components, and a recommended procedure for product committees when specifying permissible temperature limits. The publication is informative (technical report) rather than normative.

General information

• Status: Published (consolidated technical report).
• Publication date: 24 March 2009 (consolidated edition 2.1: IEC TR 60943:1998+A1:2009).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 29.020 — Electrical engineering in general.
• Edition / version: Edition 2.1 (second edition 1998 with Amendment 1:2008 consolidated, often shown as IEC/TR 60943 Ed.2.1 b:2009).
• Number of pages: 117 pages (consolidated PDF bilingual EN/FR).

Key bibliographic details (edition, page count, ICS, stability) are recorded in the IEC webstore and confirmed by national and commercial standards catalogues.

Scope

This technical report is intended to guide engineers, manufacturers and product committees in estimating permissible values for temperature and temperature rise of component parts of electrical equipment carrying current under steady‑state conditions. It addresses: theoretical background on electric contacts and contact resistance; ageing mechanisms affecting contact resistance; methods to calculate temperature rises of contacts and connection terminals; recommended maximum permissible temperature and temperature rise for various components; and a recommended procedure for product committees when specifying permissible limits. The consolidated publication incorporates the second edition (1998) and its 2008 amendment.

Key topics and requirements

• Structure and materials of electric contacts and connection terminals.
• Calculation and measurement methods for ohmic/contact resistance.
• Ageing and degradation mechanisms that influence contact resistance over time.
• Formulas and worked examples for computing steady‑state temperature rise of contacts and terminals under specified currents.
• Guidance on maximum permissible temperatures and temperature rises for contacts, terminals and connected conductors.
• Recommended procedure for product committees to specify permissible temperature limits in product standards or specifications.

These topics are presented as guidance (informative) and intended to support product committees and designers rather than to impose mandatory test limits.

Typical use and users

Primary users are electrical equipment designers, test and compliance engineers, manufacturers of connectors/terminals and product committees developing equipment safety and performance requirements. The TR is used to set or justify temperature‑rise limits in component and product standards, to support thermal design and to inform acceptance criteria used by testing laboratories.

Related standards

This TR consolidates IEC TR 60943 (Ed.2, 1998) with its Amendment 1 (2008) into the 2009 consolidated version. It is complementary to product‑specific series and safety standards that specify terminal and contact temperature limits (for example device and equipment standards in various IEC series), and is intended to be used by product committees when they set permissible temperature rises. Users should check relevant equipment‑specific IEC standards for mandatory requirements that may reference or supersede guidance in this TR.

Keywords

permissible temperature rise; temperature rise; contacts; contact resistance; terminals; connection terminals; steady‑state heating; ageing mechanisms; thermal design; IEC TR 60943.

FAQ

Q: What is this standard?

A: It is IEC Technical Report TR 60943 (consolidated as IEC/TR 60943:1998+A1:2009, edition 2.1) providing guidance on permissible temperature rise for parts of electrical equipment, in particular terminals.

Q: What does it cover?

A: It covers theory and practical guidance for estimating contact and terminal ohmic resistance, mechanisms of ageing, calculation methods for temperature rise under steady currents, recommended maximum permissible temperatures/temperature rises for components, and a recommended procedure for product committees to set limits. The content is informative guidance rather than prescriptive test requirements.

Q: Who typically uses it?

A: Design and test engineers, manufacturers of terminals and connectors, conformity assessment bodies and IEC product committees that need authoritative guidance when specifying temperature‑rise limits in product standards.

Q: Is it current or superseded?

A: The document provided here is the consolidated 2009 edition (Ed.2.1: IEC/TR 60943:1998+A1:2009). Users should check the IEC webstore or their national standards body for any later amendments, confirmations or withdrawals beyond the 2009 consolidated publication. As recorded in IEC bibliographic data, the consolidated edition was published 24 March 2009.

Q: Is it part of a series?

A: It is a standalone IEC Technical Report (TR) designated 60943. It supplements product‑specific IEC standards by giving guidance; it was prepared by TC 32 (Fuses) drafting groups and referenced as a guidance document for committees that set terminal/contact temperature limits.

Q: What are the key keywords?

A: Permissible temperature rise, contact resistance, terminals, temperature rise calculation, ageing mechanisms, steady‑state heating, thermal limits.