Arc flashes and blasts – when a flashover of electric current leaves its intended path and travels through the air from one conductor to another – can reach temperatures upwards of 19,000°C or 34,232 °F, hotter than the surface of the sun. They’re just some of the dangers that exist when working with high-voltage electricity.
Electrocution is another. It’s the second leading cause of traumatic incidents in construction in New South Wales, Australia. In the United States, according to the National Safety Council, electricity ranks sixth among all causes of occupational incidents and in Canada the Association of Workers’ Compensation Boards of Canada reports electricity as one of the leading causes of workplace injuries.
On PCL utility-scale solar builds across North America and Australia, there are many electrical safety hazards. When dealing with equipment such as solar panels, where the flow of electricity is involved, specialized safety skills and procedures are mandatory. Although solar panels are considered low-voltage equipment, workers must take extra caution and care, as the equipment is always live. Solar panels cannot be turned off, so when exposed to light the panel can potentially cause electrocution. According to SafeWork New South Wales, Australia there have been more than 1,000 occupational electricity incidents recorded since 2020 in the state. In the U.S., the Bureau of Labor Statistics reports that since 2020 2,210 occupational incidents involving electricity have occurred and in Canada the Electrical Safety Authority reports that 13% of all lost-time injuries are due to electrical hazards.
“The results of improper training, work practices and safety measures can be catastrophic,” says Mark Wintle, superintendent, PCL Solar in Australia. “Having the right people with the right training, and having safety measures in place that go above and beyond, are critical to site safety every day.”
Once a project is connected to the grid, both medium and high-voltage electricity is present, and new safety hazards arise. High voltage can range up to 230,000 Volts alternating current or is classified as exceeding 1,500 Volts direct current. If proper practices are not followed, high-voltage electricity can cause injuries or fatalities from electric shock, burns from arcing, explosions or fire, toxic gasses released by burning or arcing, and violent muscle contractions.
Wintle and three of his colleagues hold critical roles as trained high voltage operators in Australia while Donny Kiehn and Mathew Watson are trained high voltage substation operators in North America. With their extensive training and experience, these specialized professionals are dedicated to ensuring safety around high voltage electricity on all PCL solar project sites.
Becoming a high-voltage operator is no easy task. To be certified, individuals attend three days of in-person training where they learn safety and environment regulations, review electrical practice and theories, and learn about high-voltage operation, including switching operations and procedures. Switching procedures outline the process and protocols that must be followed when opening and closing circuit breakers and disconnecting switches to energize, de-energize, or isolate equipment. The training doesn’t stop there. Once certified, it is required to attend a refresher every three years to stay up to date on best practices and to recertify.
During commissioning, high voltage operators conduct switching operations and procedures multiple times a day. Operators ensure all safety protocols are followed and procedures are carried out in teams while wearing their own personal protective equipment (PPE) based on the arc flash PPE category. The PPE can include fire-resistant clothing or even an entire fire-resistant suit complete with a hood, face shield and insulated gloves with leather boots. Additional PPE may include insulated mats and blankets, shotgun sticks – a specialized hot stick that allows the capture of certain types of clamps and devices in its hook - for operating switches or installing personal protective grounds. High voltage operators also keep all team members safe with the following measures:
- Exclusion zones
- The minimum safe distance from live power.
- Entry by permit only
- A formal, written, safe system of work to control potentially hazardous activities.
- Circuit Isolation
- Prevents dangerous voltages from passing to the operator in the event of an electrical fault/failure or during a surge from lightning.
- Gates and locked doors
- To limit entry to those who only have explicit entry permissions and prevent employee injury for those who do not have permission.
- Testing for de-energization
- Verifying that there is no electrical current flowing to or from the equipment or circuits.
High voltage operators can employ the use of remote-control switches typically located in a control building to operate, trip and close circuit breakers from a safe distance that is outside the arc-flash boundary, reducing risk to high voltage operators.
PCL’s culture of safety on solar projects is more than a reminder to work safe – it’s about investing in employees’ skills, which leads to project success and ensures everyone goes home safely at the end of the day. Specially trained employees and experts on project teams also reduce the need for contracting specialized skills, therefore keeping project costs lower for clients.
While electricity powers our lives, the potential it has to cause harm cannot be taken lightly, especially when high-voltage electricity is involved. Construction projects will always involve some form of electricity and the unique safety hazards it presents, but with properly trained people and safety protocols, the hazards can be reduced, and operations can continue safely. “Electricity is high risk work that needs to be managed very carefully by experienced professionals and PCL invests in having experienced employees on project sites,” Wintle says. “At PCL, safety is always a number one priority.”