Workplace Health and Safety Queensland and Queensland’s Electrical Safety Office have been auditing and investigating a number of solar farms across the state, following a number of incidents in which workers were injured as a result of electric shocks.
30 solar farms have been visited over the past 12 months with 67 notices issued, and Electrical Safety Office inspectors have issued improvement and infringement notices for unsafe isolation and securing and protection of cables, unlicensed work, earthing, marking and labelling and testing.
Electrical workers and electrical contractors have also been referred to the Electrical Licensing Committee for consideration of disciplinary action.
Electrical and non-electrical workers have received electric shocks and arc flash injuries while working on or near energised DC string cabling and DC busbars, and the Electrical Safety Office said all cables and connections should be isolated before work is commenced on cables or connections, or near where they may be disturbed.
There have been several incidents working on, in or near combiner boxes and connections at combiner boxes.
In one incident, a worker sustained burns from an electric arc while changing connectors in a solar panel combiner box at a solar farm.
In another incident, a worker received an electric shock and burns to his thumb and fingers, after attempting to identify a route for a SCADA extra low voltage cabling through a power conditioning unit bus bar section.
He placed his hand inside the cabinet inadvertently contacting a 1300-volt DC bus bar.
Inspectors have also found plastic cable ties being used to support DC cables, and the Electrical Safety Office said plastic cable ties must not be used as the primary means of support as plastic cable ties installed under an array are still exposed to reflective UV radiation.
Other non-compliant issues include inappropriate cable clips not adequately supporting cables where panels rotate, non-UV rated conduits installed for mechanical protection of cables, and DC cables being subject to mechanical damage from sharp edges.
Inspectors have found unlicensed people carrying out cable installation (including 1500V rated DC mains underground cable and PV solar string cables), making connections for the earthing system, and making the plug-in connections of the interconnecting wiring between PV panels.
There have also been non-compliances related to testing and commissioning of installations, and this includes electrical contractors not testing earthing continuity between all PV module frames to the earth system of the support structures.
The Electrical Safety Office also said marking and labelling of all equipment, control and protection devices, and isolation devices and their relationship to each other has not always been clear enough to enable persons to make informed decisions during switching or isolation activities.
Workplace Health and Safety Queensland and the Electrical Safety Office reminded principal contractors, electrical contractors and workers at solar farms that:
· A business or undertaking that contracts to perform electrical work must have a current Queensland electrical contractor licence. This includes sub-contracting electrical work
· Only licensed electrical workers can perform electrical work
· Risk assessments, safe work method statements (SWMS), and isolation procedures must be undertaken before any work is performed. The hierarchy of control must be applied as part of the risk management process.
Principal contractors and electrical contractors at solar farms must ensure all electrical risks associated with constructing, operating and maintaining DC solar systems are properly managed.
They also have a duty to ensure the work is conducted in a way that is electrically safe and should take note of the incidents highlighting the electrical risks working in and around combiner boxes.