Solar panel concerns

Concerns have been raised regarding the electrical safety of solar photo voltaic (PV) installations. Reverse polarity can occur if polarised DC isolators are connected incorrectly by the installer.

The Electrical Safety Office (ESO) is encouraging all solar panel installers to follow correct connection instructions. Failure to follow these instructions could lead to the isolator failing if it is manually operated under load.

Installers have the obligation to ensure all installations are electrically safe including verification that any polarised DC isolators are installed correctly. This may require installers reviewing installation instructions and also revisiting installations to verify the correct polarity of the polarised DC isolator.

The installer must remember that the solar panels are the DC supply source. Correct polarity connection of the wiring from the solar panels must be made to the correct terminals of the polarised DC isolator. This is critical to ensure current flow through the DC isolator is correct to enable interruption of the DC arc when the isolator is operated.

Alternatively, the installer may consider using a non polarised DC isolator where the devices are designed to operate correctly with the DC wiring connected without regard to polarity.

Where it is identified that a DC isolator has been connected incorrectly then the installer, as part of meeting their electrical safety obligation, would need to establish whether the isolator is damaged as a result of any switching under load. If this cannot be established then the isolator must be replaced.

It is important to always follow correct shutdown procedures. Shutdown procedures should be located at the inverter and/ or on the main switchboard. If you are unsure of the shutdown procedure then contact the manufacturer or installer.

The Clean Energy Council (CEC) website has technical papers highlighting this issue.