Through a forensic investigation, it can often be determined whether electrical shock conditions were present, whether an electric shock occurred, and if electric shock did occur, the cause or causes. Variables such as the type of product or equipment, environment, service history, and who was injured may all influence causation and standard of care.
This article outlines the questions that should be asked, and discovery items to request, in an investigation of an electrical shock injury.
Electrical Shock Investigation Discovery Questions - Expert Article
Conditions for electric shock can arise anywhere electricity is used. Electrical circuits, appliances, light fixtures, and safety devices etc. require proper manufacturing, installation, service, and testing to prevent shock injuries. These roles are not always performed by individuals and companies with proper qualifications and competency.
At the outset of a new case, there are certain pieces of information that can be helpful for your expert’s investigation. Having this information available when sourcing an expert can enable experts to provide initial feedback on the technical merits of various case strategies.
Fundamentals of Electricity
The foundational terms and concepts of electrical engineering can be confusing to industry outsiders. For a primer on voltage, resistance, current, and how each variable affects the injury potential in electrical shock cases, consider reading our article on the Fundamentals of Electricity.
Discovery Questions for Electrical Shock Cases
Investigations can be aided by information from things like the examination of evidence, service records, model numbers, prior complaints, electrical testing, and descriptions of past performance and history. Preserving evidence for examination and obtaining service records for post-incident corrections is ideal, though it is not always possible. If there is evidence available, regardless of whether changes or corrections have been made, your expert will want access to it.
What were the qualifications of the person who was shocked?
Many electrical shocks occur during the installation or servicing of equipment. It may be relevant to determine the training and qualifications of the injured party for the electrical work being performed. Did the injured person follow best practices? Should they have known best practices? Did they know enough to understand the risks associated with their actions?
Are product labels in place and in good condition?
Many electrical products will feature warning labels to notify of potential shock hazards. Your expert will likely want to know if warning labels were covered, removed, or damaged in a manner that limited their effectiveness, and if they aligned with applicable standards and regulations. Additionally, were they in a language the user could understand?
Was the equipment verified to be de-energized prior to work? Did the work require the equipment to be energized during servicing?
Servicing electrical systems is often performed after the power has been turned off, a voltage detector has been used to verify that the power has been successfully turned off, and locking out and tagging out of the power has been completed. However, there are also activities that can only be performed with the power turned on. Analysis of the work being performed is often part of an investigation.
Were energized components guarded?
This is particularly relevant for incidental contacts. For instance, were tools required to remove protective covers? If maintenance is performed on energized equipment, have insulated connectors been used to protect against accidental contact? In some types of equipment, it may have been appropriate to install an interlock to de-energize systems before contact can be made.
Have other parties serviced the equipment?
Service records are an obvious place to start, but absent documentation, an expert may still be able to determine a device’s relative service history through a visual inspection. Is paint scuffed from tool marks or around access panels? Is there any evidence of repair, indicated by field soldering, wiring alterations, or an inconsistent use of electrical tape or wire nuts?
Has the building wiring been modified since the fixture or appliance was installed?
Amateur electrical work can cause a host of problems, including overloading a circuit, negating protective devices, or causing fault conditions which means to have current flow in an unintended path. Performing a visual inspection of conduit, wiring, and other system components for consistency may reveal alterations which could affect liability.
Are injuries commensurate to the exposure?
Electrical injuries can range from pain, muscular contractions, and difficulty in breathing, to burns, cardiac arrest, respiratory failure, or death. The severity of injury is primarily based on the amount of current, the duration of current and the path of current through the body. For a more in-depth view of this topic, see our article on Electric Shock Injuries.
Investigating Electrical Shock Cases
The prevention of electrical shocks is accomplished by keeping the flow of electricity in intended paths, safety devices acting quickly to de-energize when electrical currents flow in unintended paths, and by grounding methods for preventing differences in voltage levels on exposed surfaces.
Electrical shocks are also prevented by enclosing or guarding against contact with energized surfaces and the prevention of the intrusion of materials, such as water, into electrical equipment. Besides electrical injuries occurring from electrical shock, they can also occur as a result of arc flash events.
The electrical engineers at Robson Forensic regularly investigate electrical shock injuries and electrocutions to determine their cause. These investigations typically include an evaluation of equipment installations in accordance with the National Electrical Code (NEC), the National Electrical Safety Code (NESC), appliances, products, and equipment designs, maintenance and repair issues, presence of defects, and the adequacy of warnings and instructions.
For more information submit an inquiry or contact the author of this article.
Electrical Engineer & Industrial Controls Expert
Leo is an electrical engineer with nearly 30 years of professional experience involving industrial controls and automation, machinery and equipment safeguarding, and process safety and construction management for industrial facilities. He applies his expertise to forensic casework involving injuries, system performance claims, and intellectual property disputes.