Two standards sit behind most electrical compliance checks on a solar job. Neither is an STC rule in itself, but the STC claim declares compliance with the electrical rules that apply, so both can affect a claim.
AS/NZS 3000: the wiring rules
AS/NZS 3000 is the main wiring standard. For solar, auditors look at:
- Protection devices and switchboard arrangements, including labelling.
- Cable sizing, installation and protection.
- Earthing, and testing results recorded on the paperwork.
- Isolation points and clear identification.
The array side has its own standard, which is covered in AS/NZS 5033. Licensed electrical work, certificates of electrical safety and notifications are state requirements.
AS/NZS 4777: connection and inverter settings
AS/NZS 4777 deals with grid-connected inverter systems. The network operator specifies settings such as the regional power quality profile, voltage and frequency responses, and export limits. Inverters must be set to the correct region setting, and the settings recorded at commissioning. Problems arise when:
- The inverter is left on a default setting that does not match the network.
- Export limits agreed with the network are not applied. See export limits by state.
- The network connection approval is missing or does not match the system size installed.
How this feeds into STCs
A system that is not connected in line with network rules is not compliant with the installer’s declaration. An audit may inspect the commissioning records and settings. If these fail, the certificates may be at risk and the installer may be asked to fix them. See what happens when a system fails an audit.
What this means for installers
- Confirm network approval before commissioning and match the system to it.
- Record test results and the inverter settings every time.
- Keep the electrical safety certificate with the job file.
- Check the standard editions that apply in your state, since requirements change.
For the evidence side of this, use the STC photo requirements checklist and how STC audits work. The pillar for the scheme is STC trading. If you want a second pair of eyes before you lodge, the compliance desk at Energy Merchants pre-checks every claim.
Testing and records
Test results are the documentary proof of compliance: insulation resistance, earth continuity, polarity and, for the inverter, the commissioning checks. Store them as part of the job file and make sure the values are plausible. Copying the same figures job after job is the kind of pattern that attracts attention.
When the network and the design disagree
Occasionally the network approval is for a smaller system or a lower export limit than the design. Do not commission and sort it out later. Get the approval amended first, then commission to the amended figures. A system running outside its approval is out of step with the declaration you signed, and that is the kind of mismatch that surfaces in an audit.