Code reference · NEC Table 310.16 / 240.4(D); CEC Table 2 / Rule 14-104(2) (described, not reproduced)
Canadian (CEC) vs US (NEC) conductor sizing — what actually differs
For copper conductors 14 AWG–4/0 in raceway, the CEC's Table 2 and NEC Table 310.16 have been harmonized since the CEC's 2015 edition — the ampacity numbers match. The small-conductor overcurrent caps also match functionally (CEC Rule 14-104(2) vs NEC 240.4(D): 15/20/30 A on 14/12/10 AWG copper).
What differs: free-air tables, some derating trigger points, PV rules live in CEC Section 64 (vs NEC 690/705), and dwellings in Canada cap PV system voltage lower. We describe the Canadian rules in our own words only — the CEC text itself is CSA-copyrighted.
Practical takeaway: a US ampacity chart will usually give you the right Canadian conductor for common raceway cases, but the PV/interconnection article structure is different enough that you should not port 690/705 citations into a Canadian permit package.
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Get your document →Every numeric value on this page is computed by the CircuitProof calculation engine — the same golden-tested code that renders our permit documents — not typed by hand. Code text is paraphrased and cited; always verify against your jurisdiction's adopted edition and a licensed professional before installation. Design documentation, not a stamped drawing.
More references: NEC Table 310.16 ampacity, explained · The NEC 705.12 120% rule, actually explained · What wire size for a 100 A sub panel? · NEC 625: EV charger circuit sizing · NEC 706: battery energy storage disconnects · NEC 240.4(D): the small-conductor overcurrent caps · all 97 references