AS/NZS 3000 Section 8 asks for every installation to be inspected and tested before it is livened. AS/NZS 3017 sets out how, and in what order. The order is not a formality: each test relies on the one before it.
The sequence
- Test for de-energized. Prove there is no voltage before any other test.
- Earth continuity. The main earthing conductor first, then the earths and bonds of each circuit.
- Insulation resistance. Between live conductors and earth, and between the live conductors.
- Polarity and correct circuit connections. Each active switched, each circuit on its own neutral. A circuit with multi‑phase socket‑outlets also takes a phase sequence test, so every outlet of a type turns a motor the same way.
- Earth fault-loop impedance. With the supply on.
- RCD operation. Each RCD trips and disconnects the circuit.
Why this order
- An insulation test between live parts and earth means nothing until the earth is proven: a broken earth reads as perfect insulation.
- The loop impedance test needs the circuit livened, so polarity and insulation must already be right.
- The RCD test needs a sound earth path, so it comes last.
If a test fails, fix the fault, then repeat that test and any earlier one the fault may have upset.
Where the limits come from
| Test | Limit | Source |
|---|---|---|
| Insulation resistance | At least 1 MΩ at 500 V; a reduced voltage for sensitive equipment | AS/NZS 3000 Cl 8.3.6 |
| Main earthing conductor and bonding | At most 0.5 Ω | AS/NZS 3000 Cl 8.3.5 |
| Circuit earth (Re) and Rphe | By device, rating and size | AS/NZS 3000 Table 8.2 |
| Earth fault-loop impedance | By device and rating | AS/NZS 3000 Table 8.1 |
| RCD | Operates and disconnects; in NZ a 30 mA RCD within 300 ms | AS/NZS 3017 Cl 4.9.4; Electricity (Safety) Regulations reg 24 |
AS/NZS 3017 repeats the Section 8 figures and gives its own rounded loop impedance table. AmpSize judges Zs by Table 8.1.
Make the sheet for a board with the test schedule tool, and check a reading with the test results tool. A worked house board is in A test sheet for a house board.