Imperial Cable
Find the device rating for an old imperial cable.
Questions
Each answer describes what this tool calculates. The result is a design aid. Verify against the current standard.
What does the imperial cable tool do?
The tool reads AS/NZS 3000:2018 Table I1. Pick the imperial size, the installation method and the insulation. AmpSize then reports the largest circuit-breaker, and the largest existing fuse or plug-in circuit-breaker, that the table prints for that conductor. Appendix I gives the scope.
Can I fit a rewireable fuse to an old circuit?
No. AmpSize treats the second column of Table I1 as an existing device only. Clause 2.5.2 governs that point, and Note 2 under the table points at it. Use that rating where a rewireable fuse or a plug-in circuit-breaker is already in place on an alteration or a repair.
How is the metric equivalent worked out?
AmpSize calculates the conductor area from the wire count and the wire diameter, then reports the nearest standard metric size. That area is arithmetic, not a value read from the standard. AmpSize does not encode Table I2, the table for cables connected in parallel. Read it in the standard for that case.
Do the Table I1 ratings apply to every installation?
No. Note 1 under Table I1 sets the conditions the ratings hold under. Read it on the page. Then check the route, the grouping and the voltage drop before you rely on a value.