Derating Factor Matrix — 4 Standards Comparison
Free download · A3 landscape (420 × 297mm)
Derating factors can make or break a cable design — an 80A cable might only be good for 50A after temperature and grouping corrections. This A3 poster presents a combined derating factor matrix covering all four major standards: AS/NZS 3008 (Tables 22/25/27), BS 7671 (Tables 4B1/4C1), IEC 60364 (Tables B.52.14/17), and NEC (Table 310.15(B)(1)). The matrix uses a clear color gradient — green (>0.8), amber (0.6–0.8), and red (<0.6) — so you can instantly spot where aggressive derating applies. A side panel covers soil thermal resistivity correction factors for direct-buried cables. Essential for engineers who frequently cross-reference derating factors across different standards, or for training rooms teaching multi-standard cable sizing methodology.
What's Included
How to Print
- ●Print on A3 (297 × 420mm) or tabloid (11 × 17")
- ●Color printing required for comparison highlights
- ●Use a professional print shop for best results
- ●Frame or laminate for long-term office display
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Need precise calculations beyond quick reference? Try our free online calculator with full clause references and professional report output.
Open CalculatorRelated Downloads
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Free printable A3 wall poster comparing cable current ratings across AS/NZS 3008, BS 7671, IEC 60364, and NEC side-by-side. Pin in your design office.
AS/NZS 3008 Card
Free printable pocket card with Cu/XLPE cable current ratings from AS/NZS 3008 Table 13/14 and derating factors from Table 22/25/27. Credit-card size, print and laminate.
BS 7671 Card
Free printable pocket reference card with cable current ratings from BS 7671 Table 4D2A and derating factors from Table 4B1/4C1. Print on cardstock for site use.
NEC 310.16 Card
Free printable NEC Table 310.16 ampacity reference card with 310.15(B)(1) correction factors. Credit-card size for wallet or toolbox.
Frequently Asked Questions
What paper should I print this on?
Print on A3 in color — the color coding is essential for quick reference. Use a print shop for best quality. Frame or laminate for office wall display.
Can I distribute this to my team?
Yes. Free to print and distribute. Pin one in every design office and training room.
What standard does this reference?
Cross-references derating tables from AS/NZS 3008.1.1:2017, BS 7671:2018+A2, IEC 60364-5-52, and NEC/NFPA 70:2023.
How often is this updated?
Updated when any of the four standards publishes a new edition with revised derating factors.