Inspectors find unsafe electrical practices on solar farms

Audits and investigations around Queensland solar farms over the past 12 months have revealed a number of properties are not ensuring adequate electrical safety.

These investigations have been carried out by the Electrical Safety Office (ESO) and Workplace Health and Safety (WHS), with over 30 solar farms visited and 67 notices issued.

According to an ESO safety update, improvement and infringement notices were issued for actions such as 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.

In some instances, inspectors found unlicensed people carrying out cable installation (including 1500 V 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.

The safety update said electrical and non-electrical workers have also received electric shocks and arc flash injuries while working on or near energised DC string cabling and DC busbars. All cables and connections should be isolated before work is commenced on cables or connections, or near where they may be disturbed.

Several non-compliances were issued related to testing and commissioning of installations. This includes electrical contractors not testing earthing continuity between all PV module frames to the earth system of the support structures.

According to the ESO, at one property, a combiner box caught fire when the PV string fuses were being inserted. It was identified that a PV string was connected with incorrect polarity. The string conductors were incorrectly identified and the testing conducted was inadequate.

Principal contractors, electrical contractors and workers at solar farms are reminded by the ESO and WHS 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.
   

Installation requirements can be found in AS/NZS 3000 wiring rules and, in the absence of other Australian installation standards or codes, you can obtain guidance from AS/NZS 5033 Installation and safety requirements for photovoltaic (PV) arrays.

The ESO and WHS are developing a code of practice to give further guidance for safety at solar farms.

Image credit: ©stock.adobe.com/au/Jürgen Fälchle