LV Circuit Breaker Selection Guide Card
Free download · 85 × 54mm (credit card size)
Selecting the right circuit breaker requires understanding a matrix of ratings and coordination requirements. This pocket card distils the critical selection criteria onto a single reference. The front explains key ratings: In (rated current), Ics (service breaking capacity), Icu (ultimate breaking capacity), Icw (rated short-time withstand), and the fundamental rules — In ≥ IB and In ≤ Iz, with Ics ≥ Ipsc at point of installation. Selectivity types (current, time, energy) are tabulated with conditions. The reverse covers Type 1 vs Type 2 motor starter coordination, cascading (back-up protection) rules and limitations, and IEC 60947-2 test duty cycles. QR links to ECalPro Cable Sizing Calculator.
What's Included
How to Print
- ●Recommended paper: 250–300gsm cardstock
- ●Print double-sided, flip on short edge
- ●Cut along crop marks with a paper trimmer
- ●Laminate with 80–125 micron pouches for durability
- ●Fits in wallet, toolbox, or pocket
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Frequently Asked Questions
What paper should I print this on?
Print on 250–300gsm cardstock for durability. Use duplex (double-sided) printing and cut along the crop marks. Laminate with 80–125 micron pouches for long-term site use.
Can I distribute this to my team?
Yes. All ECalPro reference cards are free to download, print, and distribute within your organization. Keep the ECalPro branding and QR code intact.
What standard does this reference?
This card references IEC 60947-2 for circuit breaker ratings and test requirements, and AS/NZS 3000:2018 Clause 2.5 for installation selection rules.
How often is this updated?
Updated when referenced standards are revised. Current card reflects IEC 60947-2 latest edition and AS/NZS 3000:2018.