Iec 60947-2 Pdf !!better!!
This guide provides an overview of the IEC 60947-2 standard , which governs the design and performance requirements for low-voltage circuit breakers in industrial and commercial applications. CIRCUIT BREAKER SUPERSTORE 1. Purpose and Scope
IEC 60947-2 is part of a broader series of standards for low-voltage switchgear and controlgear. It is specifically designed to ensure the safety and reliability of circuit breakers used in complex electrical infrastructures. UBA Universidad de Buenos Aires Voltage Limits: Covers AC systems up to and DC systems up to Targeted Equipment:
Includes Air Circuit Breakers (ACBs) and Molded Case Circuit Breakers (MCCBs). Intended Users:
Manufacturers, facility managers, and electrical engineers in industrial settings. Schneider Electric Blog 2. Core Technical Specifications
The standard defines several critical performance ratings that engineers must use when selecting a circuit breaker: Rated Ultimate Short-Circuit Breaking Capacity ( cap I sub c u end-sub
The maximum short-circuit current a breaker can handle without permanent damage. Rated Service Short-Circuit Breaking Capacity ( cap I sub c s end-sub iec 60947-2 pdf
The level of short-circuit current the breaker can interrupt and then continue to operate normally. Selectivity Categories: Category A: Breakers without a deliberate short-time delay. Category B:
Breakers designed for selectivity with a short-time withstand current ( cap I sub c w end-sub ) and associated delay, often used for upstream protection. Current Limiting:
Defines "current-limiting circuit breakers" as those that prevent short-circuit currents from reaching their peak value by interrupting the circuit extremely quickly. Schneider Electric Blog 3. IEC 60947-2 vs. IEC 60898-1
A common point of confusion is when to use this standard over IEC 60898-1 , which also covers circuit breakers. Schneider Electric Blog IEC 60947-2:
Industrial applications where breakers are operated by instructed persons and environments may have high short-circuit levels. IEC 60898-1: This guide provides an overview of the IEC
Household and similar applications where breakers are typically used by uninstructed persons. Schneider Electric Blog 4. Accessing the Official Document As this is a copyrighted technical standard, the full IEC 60947-2 PDF
is not legally available for free download. You can obtain the official version through authorized standards bodies: IEC Webstore: Purchase the latest edition directly from the International Electrotechnical Commission Local Standards Organizations: Regional versions (e.g., BS EN 60947-2) can be found at the or similar national bodies. Manufacturer Technical Guides: Companies like Schneider Electric
often provide free technical extracts and design guides that explain standard implementation. Schneider Electric IEC 60947-2 and IEC 60898-1: A tale of two standards
IEC 60947-2 is the definitive international standard for low-voltage circuit breakers used in industrial and similar installations. Unlike the IEC 60898 standard for residential use, 60947-2 covers more complex electrical systems up to 1,000 V AC or 1,500 V DC. 1. Utilization Categories (A vs. B)
The standard classifies circuit breakers based on their ability to provide selectivity (the capacity to allow a downstream breaker to trip first without tripping the main breaker). Beware of "Free" IEC 60947-2 PDF Downloads Sites
Category A: These breakers have no intentional time delay and are not specifically designed for selectivity. They are often current-limiting, meaning they interrupt short circuits extremely quickly (within half a cycle) to minimize damage to equipment.
Category B: Specifically designed for selectivity, these breakers include an intentional short-time delay and a rated short-time withstand current ( Icwcap I sub c w end-sub
). This allows them to "wait" for a smaller downstream breaker to clear a fault. 2. Critical Breaking Capacity Ratings
Beware of "Free" IEC 60947-2 PDF Downloads
Sites offering a free IEC 60947-2 pdf are almost always illegal. Penalties for using counterfeit standards can include fines and legal liability, especially if a certified product fails and causes injury. Moreover, old versions (e.g., the 2003 or 2007 editions) contain obsolete test methods. Always use the latest edition (currently Edition 6.0, published 2021-09, with Amendment 1: 2024).
2. Key Definitions
- Circuit-breaker: Mechanical switching device capable of making, carrying, and breaking currents under normal circuit conditions, and making, carrying for a specified time, and breaking currents under abnormal conditions (e.g., short-circuit).
- Rated operational voltage (Ue): Voltage at which the breaker operates.
- Rated insulation voltage (Ui): Dielectric withstand voltage.
- Rated ultimate short-circuit breaking capacity (Icu): Maximum fault current the breaker can clear once.
- Rated service short-circuit breaking capacity (Ics): Fault current the breaker can clear and still be usable (typically % of Icu, e.g., 50%, 75%, 100%).
Typical selection checklist
- Confirm system voltages (Ue) and frequency.
- Determine continuous load current → choose In above load current.
- Calculate prospective short-circuit current at device location → ensure Icu ≥ prospective fault current; prefer Ics close to Icu for serviceability.
- Check trip curve (thermal/magnetic) matches load characteristics (motor inrush, transformer magnetizing current).
- Verify coordination with upstream devices (selectivity) and downstream protective devices.
- Confirm ambient temperature derating and enclosure/installation conditions.
- Ensure required accessories and auxiliary contacts are available and compliant.
- Check markings, certificates, and test reports per IEC 60947-2.
What the standard covers
- Scope: Low-voltage circuit-breakers for a.c. and d.c. systems — definitions, ratings, performance, testing, marking, and installation guidance.
- Products: Molded-case circuit-breakers (MCCBs), insulated-case, and some types of miniature circuit-breakers where applicable.
