Solar panel electric shock warning issued

The Queensland Government has issued a warning relating to electric shocks from electric leakage. Workplace Health and Safety Queensland has received reports of several incidents of electric shocks through contact with the metallic panels and frames of some solar PV systems due to electrical leakage.

An incident such as this has the potential to cause a fall from height if the roof itself is conductive, the warning says.

The leakage, caused by the capacitance (ability to store an electrical charge) between the solar panels and dirt and water on the panels or the roof, generally increases when the solar panels are wet.

In some situations, the leakage may cause an electrical potential on the solar PV frames, the array mounting frames and any conductive materials (eg, metallic roofing material). While these voltages may not produce a fatal electric shock, in higher-risk environments such as working at heights, the reaction to a mild shock may increase the risk of a fall.

The electrical leakage is generally not an issue if a galvanic isolated PCU (inverter) is installed or the solar panels and mounting frames have been effectively bonded to earth.

Electrical leakage due to capacitance will generally cease when the PV generation system is shut down as the connection between the DC and AC is isolated.

To minimise this risk, electrical workers should, whenever possible, shut down the solar PV system before accessing the roof. It is important that the correct procedure is followed when shutting down the system.

Workplace Health and Safety Queensland suggests that any safety concerns regarding a solar PV system should be discussed with the home owner.

More information on electrical safety is available at www.electricalsafety.qld.gov.au.