As3000 Voltage Drop ((link)) Jun 2026

The fundamental rule in AS3000 (Clause 3.6.2) is that the voltage drop from the supply terminals to the load must not exceed (or 4% for standalone installations like private overhead lines).

A 32A three-phase load on a 30m run of 6mm² cable. If Table C7 gives a value of 615 for this cable, the drop is B. The Detailed Method (AS/NZS 3008) Accurate Voltage Drop Calculator AS/NZS 3008 as3000 voltage drop

If your calculation says you need 6mm² but you have a roll of 10mm² in the van, use the 10mm². There is no penalty for oversizing cables except the cost of copper. Oversizing also reduces heat and future-proofs for load increases. The fundamental rule in AS3000 (Clause 3

Pro tip: If you are running a sub-main to a distribution board, remember that this 5% includes everything —the main switchboard feed plus the final sub-circuit. Don’t use the whole 5% on the long cable run to the shed, or your GPOs inside the shed will be running on fumes. The Detailed Method (AS/NZS 3008) Accurate Voltage Drop

Sure, you don't want to fail an inspection. But voltage drop isn't just a paperwork exercise.