Tra cứu tiết diện dây dẫn tối thiểu

How this is calculated#

The tool looks up the smallest conductor that AS/NZS 3000:2018 Table 3.3 allows for a use. It is a table lookup. It does not size a cable for current or voltage drop.

1. Use. You pick the use: socket‑outlets, other circuits, signal and relay control, bare conductors, insulated flexible conductors or aerial wiring.
2. Material. You pick copper or aluminium. Table 3.3 has no aluminium row for some uses. The tool then refuses and says so.
3. Table value. The tool reads the minimum cross-sectional area from Table 3.3 for that use and material.
4. Parallel conductors. You can mark the conductors as run in parallel. The tool then compares the table value with the parallel floor and keeps the larger.
5. Size that applies. The tool gives the minimum size that applies, and names Table 3.3 as the source.

Worked example#

Aerial wiring in copper. The tool gives 6 mm². The Table 3.3 value is also 6 mm², and the source is AS/NZS 3000:2018 Table 3.3.

Limits#

• Table 3.3 carries two exceptions. Read them before you use the size.
• Exception 1 can allow a smaller socket‑outlet conductor. It sets conditions that you must meet first.
• The minimum is a floor. The cable must also pass current capacity, voltage drop and fault checks.
• Use the cable size calculator for those checks.
• Clause 3.4.3 sets more conditions on a parallel group than a minimum size.
• The tool does not read AS/NZS 3008.1.

See also: Cable size calculator, Voltage drop calculator and What size breaker for 4 mm² cable.