AS/NZS 3000-2007 AS/NZS 3000-2018 V6
The Wiring Rules: The Master Standard
AS/NZS 3000, commonly known as the Wiring Rules, is the foundation of all electrical installation work in Australia and New Zealand. For solar PV, it governs every aspect of the AC-side installation and — together with AS/NZS 5033 — the DC-side as well. The 2018 version (V6) is the current edition and supersedes the 2007 edition for all new work.
As a licensed installer, you are legally required to comply with AS/NZS 3000. Non-compliance constitutes an unsafe installation and a breach of the electrical safety legislation in each state and territory.
Key Chapters of AS/NZS 3000 Relevant to Solar
Chapter 2 — General Arrangement
Solar AC circuits must have a dedicated circuit from the switchboard
A lockable solar isolation switch (visible and accessible) must be installed at the switchboard
A dedicated solar generation meter or import/export meter must be provided in grid-connected systems
The solar circuit must be clearly labelled: "Solar PV System — Danger — Do Not Switch Off Without Isolating Solar Array First"
Chapter 3 — Selection of Wiring Systems
Circuit | Minimum Requirements | Wiring Rules Reference |
|---|---|---|
DC array string cables | UV-resistant, 1000V DC rated, double-insulated (H1Z2Z2-K or equivalent) | As/NZS 5033 + Cl. 3.8 |
DC main cable (array to inverter) | As above; single-core cables in conduit or twin-core flexible | Cl. 3.8.4 |
AC inverter output to switchboard | As per AS/NZS 3008 cable selection; V-90 or V-75 acceptable | Cl. 3.8 |
Conduit in roof cavity | Non-metallic conduit must be UV-rated where exposed; max fill 40% | Cl. 3.10.2 |
Chapter 4 — Protection
The Wiring Rules require protection against:
Overcurrent (4.3) — string fuses or string CBs required when more than 2 strings are paralleled, per AS/NZS 5033
Electric shock (4.4) — RCD (residual current device) protection required for AC circuits. Note: DC circuits cannot be protected by standard AC RCDs; DC-capable RCDs or AFCI are required where mandated
Surge voltage (4.9) — SPDs required at the main switchboard. For solar, additional SPDs at the inverter DC input are required under AS/NZS 5033
Fire (4.10) — arc fault detection required in certain configurations. Wiring in concealed or inaccessible locations must use appropriate cable types
Chapter 5 — Earthing
The earthing requirements for solar AC circuits are the same as for any other sub-circuit: a continuous protective earth conductor from the switchboard to the inverter chassis. Critical points:
The inverter protective earth must connect directly to the main earth bar — not via another circuit earth
For transformerless inverters (the vast majority of residential inverters), the DC negative is typically bonded to earth inside the inverter — installers must not add an external DC negative earth bond
An isolating transformer between the inverter and grid allows an unearthed (floating) DC system — this configuration requires a Ground Fault Detection (GFD) device under AS/NZS 5033
Chapter 7 — Special Installations (Solar PV)
The 2018 edition of the Wiring Rules includes specific clauses for PV power supply systems (Section 7.3.5, referencing AS/NZS 5033 as the primary standard). Key requirements include:
Inverter must be CEC approved (listed on the CEC Approved Products list)
Maximum system voltage: 600 V DC for residential buildings; 1000 V DC for commercial (with enhanced safety measures)
Emergency shutdown provisions — a visible, lockable AC isolation switch accessible to emergency services
Labelling of all DC conductors, isolators, and junction boxes at installation
Common Wiring Rules Violations in Solar Installations
Violation | Risk | Standard Clause |
|---|---|---|
Using AC-rated cable for DC string runs | Insulation breakdown — fire risk | Cl. 3.8 / AS 5033 |
No DC isolator at array (rooftop) | Inability to de-energise array for emergency | AS 5033 Cl. 4.3.4 |
Conduit not sealed at penetrations | Pest ingress, moisture, fire spread | Cl. 3.10.2.7 |
Missing solar generation meter | Non-compliance with network connection agreement | DNSP connection agreement |
SPDs not installed | Inverter failure after any nearby lightning event | Cl. 4.9 / AS/NZS 1768 |
No isolation switch label | Firefighter confusion during emergency | Cl. 5.7.4 / AS 5033 |
Engr. Jason Morales — Founder, SolarEnergyPH