How to calculate minimum conduit size

Modified on Wed, 27 Oct, 2021 at 9:38 PM

Cable Pro Web software will automatically calculate minimum conduit size.

The calculation of conduit size is based on the method and space factors from Standard AS/NZS 3000 [1] (see image below).

To determine the number of cables that can be installed inside a conduit the following data is required:

1. Conduit internal diameter to work out cross-sectional area.

2. Cable diameter to work out cross-sectional area.

3. Number of cables to be installed to determine space factor.

References:

[1] AS/NZS 3000:2018 Electrical installations (known as the Australian/New Zealand Wiring Rules)