Overview
IEC 60934:2019 - "Circuit‑breakers for equipment (CBE)" is the fourth edition of the International Electrotechnical Commission standard that specifies requirements for mechanical switching devices designed as circuit‑breakers for equipment (CBEs) used in household and similar applications. The standard defines the intended use of CBEs to protect internal circuits and components (for example motors, transformers and internal wiring), and also covers CBEs providing undervoltage/overvoltage protection and devices suitable for isolation. This edition is a technical revision of earlier editions and includes clarifications for type‑testing.
Key topics and requirements
IEC 60934:2019 addresses classification, construction, performance and testing of CBEs. Major technical topics include:
- Scope and definitions for CBEs, protection modes and key terms (trip‑free behavior, poles, releases).
- Classification by number of poles, mounting/connection method, operation and tripping mode.
- Rated quantities and characteristics such as rated current, rated voltages, switching capacity, short‑circuit and conditional short‑circuit capacities, and time‑current characteristics.
- Construction and safety requirements: mechanical design, clearances and creepage, terminals and terminations, protection against electric shock and suitability for isolation.
- Electrical performance: dielectric strength, temperature‑rise limits, behavior under rated switching and short‑circuit conditions, and requirements for undervoltage/overvoltage releases.
- Tests and type‑testing: type test sequences, tests for marking indelibility, terminal reliability, dielectric and insulation tests, temperature‑rise, tripping characteristics, conditional short‑circuit tests and environmental/ageing tests.
- Normative annexes covering time‑current zones, determination of clearances and creepage, certification test sequences, conductor correspondence and terminal examples.
Applications and who uses this standard
IEC 60934:2019 is essential for:
- Manufacturers and product designers developing CBEs for household appliances, consumer electronics and similar equipment.
- Compliance and certification bodies conducting type testing and product certification.
- Test laboratories and quality engineers responsible for verifying mechanical, electrical and safety performance.
- OEMs and system integrators specifying protective devices for internal equipment circuits (motors, transformers, internal wiring) and for products that require isolation or undervoltage/overvoltage protection.
Using IEC 60934 helps ensure that CBEs meet recognized safety, performance and interchangeability expectations for equipment‑level circuit protection.
Related standards
IEC 60934 should be used alongside other IEC and national standards covering product safety, wiring, short‑circuit protection and electromagnetic compatibility for complete compliance and system design (refer to relevant IEC publications and national regulations for cross‑references).