Professionally trained and certified Derek, who was called to the site to investigate an electrical fault at a large PV solar facility, suffered burns to his face and arms in an arc flash caused by a high-current 480 VDC discharge. Diagnosing an unusual solar farm and assuming that the system was de-energized set the stage for the accident. Derek located the auxiliary transformer supplying the low-voltage equipment; after switching the breaker to the “off” position, he tested the section that should have been de-energized to confirm that the power had been cut. However, when he saw that the cables connected to the transformer were hanging loose behind the cabinet, he thought he had found the source of the problem. As he reached for the cables with pliers, he failed to realize that the high-voltage side was still live, and a massive arc flash occurred.
The unusual layout of the lines and the loose cable reel indicated that there was a problem with the system. Derek attributes the accident to complacency based on habit and assumptions. The pliers became the path the current followed instead of his body; because the cabinet also partially shielded him from the heat, he suffered burns mostly to exposed skin such as his face and hands. He was alone during the incident. Because his skin had darkened, the iPhone’s screen did not detect his fingers; although he does not remember how he called 911, the voice assistant probably made the connection. The property owner helped him until the ambulance arrived. With burns covering more than 19% of his body, Derek underwent skin grafts and a very painful recovery. He is sharing his story to discourage others from thinking, “I’ll just do this right away.”
Why it matters
The incident shows that professional training and certification alone do not eliminate the risks arising from unusual system layouts and mistaken assumptions of safety. In solar installations, considering one section de-energized may not mean that all sides of the connected equipment are safe; for this reason, the instinct to locate a fault quickly can turn into a critical safety vulnerability. The fact that the accident happened to a technician working alone also demonstrates how decisive the ability to call for emergency assistance and receive on-site support can be after a serious injury. Derek’s long and painful recovery shows that the consequences of seemingly minor irregularities in electrical maintenance are not limited to equipment damage, while leaving open the question of through which points and how energy should be verified in similar work.