The voltage value to which dielectric tests and creepage distances are referred. It represents the maximum permanent voltage the breaker can withstand safely without insulation breakdown. 3. Rated Impulse Withstand Voltage ( Uimpcap U sub i m p end-sub
A complete official IEC 60947-2 PDF includes several critical annexes that address additional functions integrated into modern circuit breakers:
The fault current the breaker can interrupt and still remain fully operational. IEC-60947-2-2016-AMD1-2019.pdf - iTeh Standards
(Rated Impulse Withstand Voltage): The peak value of an impulse voltage wave that the equipment can withstand without insulation failure. It determines the overvoltage category. Current Ratings and Trip Thresholds Incap I sub n iec 60947-2 pdf
For the electrical professional, obtaining the is an investment in safety, compliance, and professional competence. The sixth edition, published in 2024, represents the state of the art in circuit-breaker standardization, with significant updates covering isolation suitability, EMC, testing procedures, and more.
When designing switchgear, submitting technical submittals for approval, or performing power system coordination studies, referencing the direct text of the IEC 60947-2 standard ensures:
Designed for domestic and household applications (e.g., Miniature Circuit Breakers or MCBs). It assumes the devices will be operated by uninstructed users (laypeople) and features rigid, non-adjustable tripping curves. Core Technical Parameters Defined by the Standard The voltage value to which dielectric tests and
The type of you are configuring (thermal-magnetic or electronic).
IEC 60947-2 is a standard that outlines the requirements for circuit-breakers and fuses used in electrical installations. The standard is part of the IEC 60947 series, which covers low-voltage switchgear and controlgear. IEC 60947-2 specifically deals with circuit-breakers and fuses designed for use in electrical power distribution systems, industrial applications, and residential buildings.
| Parameter | IEC 60947-2 | IEC 60898 | |-----------|-------------|------------| | Pollution degree | 3 | 2 | | Overload trip accuracy | ±20% typical | ±10% | | Ics requirement | % of Icu (e.g., 50–100%) | 100% of Icn (for domestic) | | Isolation marking | Yes | Optional | Rated Impulse Withstand Voltage ( Uimpcap U sub
Elias opened the PDF. It was a dense, technical document, hundreds of pages long, filled with diagrams, tables, and precise definitions.
IEC 60947-2 serves as the backbone of industrial low-voltage electrical safety. By standardizing performance ratings like Icucap I sub c u end-sub Icscap I sub c s end-sub Icwcap I sub c w end-sub