Wire Gauge and Cable Sizing Guide for Lighting Exporters

Cable size is where lighting quotations quietly carry risk. Under-specify the conductor and a project fails inspection or, worse, runs hot behind a ceiling; over-specify and every metre of every circuit costs more than it should. This guide collects the sizing reference that export projects argue about most: the mm²-to-AWG translation between metric and North American drawings, typical ampacity by conductor size, and the low-voltage drop arithmetic that governs LED strip runs. All ampacity values are illustrative for common PVC/XLPE building cable in typical installation conditions — the prevailing local code (IEC 60364-5-52, NEC, AS/NZS 3000 and their national variants) always governs the final selection.

Conductor size reference: mm², AWG and lighting use

Illustrative values for copper conductors at 70-90°C insulation in typical enclosed installation conditions. Derating for grouping, ambient temperature and insulation class is code-specific — size with the local standard, not this table alone.

Low-voltage drop: the strip-light problem

Mains circuits rarely stress cable size — a 100W flood draws under half an amp at 230V. Low-voltage strip is different: the same 100W at 24V draws over 4 A, and at 12V over 8 A, so voltage drop across the run becomes the real constraint. Keep drop below 3% on low-voltage runs (and total circuit drop under 5% including mains side) or the far end visibly dims and shifts colour.

Illustrative single-feed figures. Beyond about 5 m, the cheapest fix is usually a higher-voltage system (24V over 12V, or constant-current 48V for long lines), not thicker copper.

What export buyers should check on cable specs

• Copper, not copper-clad aluminium. CCA conductors read the same gauge on the jacket and cost less — and run hotter, break at terminations and fail code in most export markets. Ask for the conductor material in writing.
• Harmonised codes tell the story. H05VV-F and H05RN-F are 300/500V flexible cords; H07RN-F is 450/750V rubber for outdoor duty. A quotation that says "PVC cable" with no harmonised number has not specified anything.
• Insulation temperature rating matters in fixtures. Luminaire internal wiring near the source often needs 90°C or 105°C rated silicone or PTFE, not generic 70°C PVC — one of the first things labs check in EN 60598 testing.
• AWG and mm² are not exact twins. 1.5 mm² is slightly smaller than 16 AWG; on international projects, size to the stricter of the two drawings rather than assuming equivalence.
• Drivers change the load. Inrush and power factor matter on long circuit runs with many drivers; a circuit that passes ampacity can still trip on inrush — split the feeds rather than upsizing blindly.

Cable in the product line

Industrial and outdoor lines carry the heaviest cable decisions: feeder sizing for high-bay banks under industrial lighting, rubber-jacketed and UV-stable supply cable for outdoor and solar lighting (where the solar sizing arithmetic also sets battery-to-lantern cable runs, per our solar sizing guide), and fire-performance requirements on commercial circuits under commercial lighting. State conductor material, harmonised cable code and insulation class on the inquiry and the BOM comes back auditable — which is what inspectors, and ten-year warranty claims, actually read.