At some point, most people become at least a little bit complacent about some facet of their lives. In the electrical industry, all too often, electricians and technicians use the fact that they were not killed or injured by past mistakes as proof that they will continue to stay out of harm’s way in the future. When it comes to electricity, a positive interpretation of negative reinforcement can prove to be deadly.
In this case, we examine an electrical contact incident that should never have occurred — and consequently would have never happened without the string of bad choices made by all parties involved. It is one of those cases with enough blame to go around for everyone. It also demonstrates that the rules for industry best practices are in place for a reason.
Two electrical contractors (Contractor A and Contractor B) were working on a site, each tasked with routing wires through a mechanical room in a publicly used building. Contractor A was pulling wire to power a control unit; Contractor B was performing general electrical work.
Both contractors were working in close proximity, and each had to route wires so that they passed through the dead space below a 480V, 3-phase main distribution panel. Because the building was already occupied, turning the lights out during the workday would have been problematic. Therefore, efforts were made by all parties to keep the power on during business hours.
The sequence of events allegedly began when Contractor A, tasked with routing control wiring, was using a lengthy metal fish tape to try to reach from one location to another via a conduit.
After pushing drastically more tape than should have been necessary into the conduit, the facility suddenly went black.
Upon inspection, it was determined that the fish tape had exited the conduit into the dead space below the 480V distribution panel. As more tape was pushed into the space, a conductive spider web of fish tape rapidly formed. As the web expanded, it climbed higher into the dead space until contact was made between phases, causing the system to trip out.
Amazingly, no one handling the fish tape was injured, nor was there any damage to the main panel. Based on testimony from the involved parties, the workers cleaned up the mess, removed the fish tape in pieces, and re-energized the panel. No harm — no foul. If the story had ended there, there would be no Forensic Casebook for me to write. Unfortunately, that was not the case.
Twenty-four hours later, Contractor B was on-site, starting to plan the routing of his wires. The actual routing was to be done during a planned shutdown, during which time the main panel was to be de-energized. Although Contractor B had been made aware of the incident from the night before, there was conflicting testimony as to what they had actually been told about the existence of any remaining fish tape left in the dead space under the panel. Later on, Contractor B would testify that he had been told by Contractor A that space was clear of any conductive debris from the night before. Contractor A disputed this testimony.
At the time of the incident, the front cover of the distribution panel had been removed. The three phases of the 480V system were exposed at a depth of 1.5 in. beyond the threshold of the front panel.
Two individuals were working in the mechanical room. While the plan was to actually route the wires during the scheduled shutdown, it was decided to use time prior to the shutdown to gather information about wire placement so as to get a head start on preparation for work to be done during the shutdown.
One man was at one end of the lineup of electrical equipment, jiggling the wire in question. The other (the victim, an electrician) was approximately 6 ft away, and was last observed kneeling or laying in front of the main panel with a flashlight in his right hand. The testimony by a coworker of Contractor B, who looked in through the door of the electrical/mechanical room shortly before the incident, was that he was positioned in such a way as to observe the dead space below the panel while maintaining a perceived safe distance from the energized bus bars. Neither individual could see the other at the time of the incident. There were no witnesses at the moment of the actual contact.
The man tasked with jiggling the wire testified that he heard arcing and smelled something burning. When he did not get a response from his partner, he stepped around the piece of equipment to find him lying on his stomach with his head inside the boundary of the electrical panel, touching one of the exposed energized phases.
The shutoff for the panel was 9 ft from the location where the incident occurred. There is conflicting testimony — and the facts are unclear — about what occurred next and who did what. Apparently, the partner grabbed a broom handle and tried unsuccessfully to free the victim from his unfortunate position. Someone else called for assistance and de-energized the panel.
Paramedics arrived soon after to find the injured man still trapped and in contact with the de-energized electrical bus. The victim had a deep laceration on the side of his neck (resultant from contact with the sharp metal edge of the enclosure) and burns to his right hands and fingers. Upon arrival at the hospital, he was also found to have a substantial burn on his head. Miraculously, the victim lived, but his days as an electrician were over.
Litigation ensued in which the injured man (plaintiff) brought suit against Contractor A, which had caused the outage the previous day.
The plaintiff claimed that but for the presence of conductive debris in the dead space under the piece of equipment, there would have been no injury.
Among many experts retained in this case, I was hired by the plaintiff to examine and explain the electric shock and reconstruct the accident to whatever extent possible.
All parties pointed fingers at each other when it came time to assume blame. The injured man was adamant he would never have breached the boundary of the distribution panel, absent some intervening event that would have drawn him into contact with the exposed and energized bus. His position was that he was maintaining a safe distance from the exposed electrical components while observing the space below the unit.
Investigation and Analysis
As is required, OSHA conducted an investigation, which resulted in the issuance of multiple citations. Most significant was a citation noting that the victim “was permitted to work in proximity to electric power circuits and was not protected against electric shock by de-energizing and grounding the circuits or effectively guarding the circuits by insulation or other means.” The citation noted that the employee “did not use protective gloves or other safety equipment.”
I visited the site more than a year after the incident. At that time, dried blood was still obvious on the inside of the cabinet. I also observed what appeared to be pieces of fish tape still in the dead space below the unit. When examining pictures of the burns on the victim’s hand, the shape of the burns looked remarkably similar to the dimensions of a piece of fish tape.
I cautiously concluded that if the victim’s testimony was taken at face value, then it was more likely than not that he would have probably contacted a stray piece of fish tape left from the night before. If that piece of fish tape was to also be in contact with energized components, it would have caused muscle contraction and could have initiated a chain reaction that drove the injured party from his position of perceived safety head first into the exposed and energized electrical bus. The voltage would have then entered through the top of his head and exited through the point where his neck contacted the razor-sharp edge of the cabinet. This would have caused further muscle contraction, driving him even further into the energized bus bars and exacerbating both the burns and serious neck laceration.
Consistent with advice that I gave to my client, the case was settled confidentially prior to trial for an undisclosed amount.
Cases such as this always remind me that the choice to modify or ignore those rules designed to protect us from injury can have a devastating outcome. Even if we put the best face on this incident for my client — assuming that the presence of a stray piece of fish tape was the initiating factor in his injury — that does not change the fact that the victim chose to place himself in proximity to an energized electrical panel without wearing any PPE.
When it comes to litigation, we always look for “legal causation” or “proximate cause” as the first step toward assessing responsibility. Here, we might say that but for the presence of the stray fish tape, this incident would not have occurred. Although that might be enough to establish legal liability — hence the settlement — that should not be enough to justify the decision to make bad choices. If good practices are followed consistently, incidents like this simply do not occur.
If one chooses not to work in proximity to energized panels without PPE, then the presence of unforeseen initiating factors becomes unimportant. One can only assume the victim would rather have his health than a monetary settlement. This case reminds us that in order to avoid becoming the subject of the next Forensics Casebook, always let standards and best practices be your guide and err on the side of caution.
Dr. Morse is an academic, researcher, and consultant who has reviewed hundreds of electrical injury cases. A full professor of electrical engineering at the University of San Diego, he can be reached at: [email protected].