Below is a list of the top 10 most common electrical work defects TechSafe Australia identified during inspections of solar installations in 2025.
These defects are for non-compliance with Australian Standards AS/NZS5033:2021 – Installation and safety requirements for photovoltaic (PV) arrays and AS/NZS4777.1:2023 – Grid connection of energy systems via inverters – Part 1: installation requirements.
The defects listed comprise about 65% of all defects identified on solar installations in 2025.
Many of the defects are work quality issues which could easily be avoided without additional costs being incurred. Reducing these mistakes will mean that less defect notices are issued, saving everyone time and money returning to properties to fix defects.
Table 1 - Most common electrical defects 2025 - Solar installations
| Standard | Clause number | Clause heading | Non-compliance identified | |
|---|---|---|---|---|
| 1 | AS/NZS 5033 | 5.6 | Recording of solar system layout | Solar system layout not shown on a plan (map or drawing) located at the main switchboard and/or meter box, fire panel. No plan of solar system layout available, or plan missing required details. |
| 2 | AS/NZS 4777.1 | 6.3 | Signs for Switchboards | IES supplementary supply shall be labelled “Main Switch (Inverter)” the grid supply shall also be appropriately identified “Main Switch Grid” or “Main isolator Grid”. Where there are multiple IES supplementary supplies each supplementary supply shall be clearly identified. |
| 3 | AS/NZS 5033 | 4.4.3 | Installation of cables | DC cabling laying on roof. DC cabling should not touch the roof without being in an enclosure. |
| 4 | AS/NZS 4777.1 | 6.2 | Signs for the switchboard to which the IES is directly connected | Switches not labelled/incorrectly labelled. A sign is required to be installed on the switchboard to which the IES is connected warning of dual supplies and the need to isolate all supplies prior to work. |
| 5 | AS/NZS 5033 | 5.7 | Shutdown procedure | System does not include a shutdown procedure that sets out steps to safely shut down the system. Shutdown procedure either missing, inaccurate or does not include required details. |
| 6 | AS/NZS 5033 | 4.4.7 | Installation of enclosures containing conductor terminations | Continuous conduit system has a section that is in an outdoor environment, and that terminates into an enclosure containing a disconnection device but has no device to drain liquid from the conduit system, or device not rated to at least IP 56. |
| 7 | AS/NZS 5033 | 5.3 | Labelling/signs for PV cables and enclosures – Wiring identification | Incorrect marking of DC conduit. Conduit that contains DC conductors must be clearly identified along the route. This identification must be easily readable, visible and not hidden from view. |
| 8 | AS/NZS 4777.1 | 5.3.6 | Alternative supply switchboard | Final Subcircuits supplied by an alternative supply from a IES shall be located in a dedicated alternative supply board Exception: where not reasonably practicable. The alternative supply final subcircuits shall be grouped. |
| 9 | AS/NZS 5033 | 5.5 | Labelling/signs for disconnection devices | Disconnection devices (DC isolators) incorrectly labelled, shutdown procedure not labelled. General failure to label disconnection devices, shutdown procedures etc. |
| 10 | AS/NZS 5033 | 5.4 | Fire emergency information | Warning signs missing, inaccurate or in incorrect location. Signage indicating presence of solar (green circular) and rated voltage and currents need to be installed. These are often not installed or the values incorrectly calculated. |
Further information
For further information, please contact us by emailing cbos.info@justice.tas.gov.au or by phoning 1300 654 499.
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