A Shocking Investigation

Workplace electrocutions occur in Australia at an incident rate of approximately 10 deaths/year. Approximately 50% of these are electrical workers but most electrical worker electric shock/near miss incidents go unreported. Such incidents present an opportunity to learn and prevent similar incidents in the future. This is achieved by a thorough investigation using trained and qualified personnel that can investigate an electric shock and/or arc flash incident at short notice. This is where PowerLogic’s Electric Shock investigation courses come into their own.

The incident rate for workplace electrocution of electrical workers is as stated above but this is the ‘tip of the iceberg’ for electric shock incidents. Most electric shock incidents go

unreported as electrical workers seek to maintain their reputation and their job. Many electrical workers and employers don’t realise that the harmonised Work Health and Safety legislation outlawed ‘live’ work back at the end of 2010. Compliance would surely prevent electrical incidents?

As electric shock incidents are occurring at an alarming rate, being prepared helps ensure businesses get the best outcomes from a bad situation. This includes having investigation procedures, forms and a report template in place and having trained personnel with the right equipment ready to get to the incident site when an unfortunate event occurs.

INVESTIGATION PROCEDURAL DOCUMENTS

The first step in the investigation process is to have all the correct documentation in place. This includes having an investigation procedure with the following requirements:

  • Making the site safe initially by a mental risk assessment and isolation of the electricity supply or rescue of the victim via an insulated crook. Of course, the incident victim may be ‘blown’ or fall clear of the ‘bities’ allowing the rescue, but the site will then need to be isolated and locked out for the investigation.
  • The shock victim should seek medical attention. The immediate symptoms and/or injuries will need to be dealt with but there can be delayed reactions and so an electrocardiogram (ECG) will be a necessity and an overnight stay possible.
  • Depending on the severity of the incident, the next step may be to notify the business’s management and the relevant authorities. This might be Worksafe, the mining regulator or other appropriate authority depending on the incident location.
  • Collecting all available evidence is important before contamination of that evidence occurs. This means investigating as soon as possible after the incident. Electrical testing will gather crucial electrical evidence that is not likely to be visible.
  • Analysis, examination and the interpretation of the evidence is to be included in the procedure.
  • The procedure needs to include the root cause analysis method(s) to be used.
  • How the hypothesis and/or alternate hypotheses are to be dealt within the incident report is needed.
  • Most importantly, the corrective and preventative actions needed to prevent recurrences need to be developed from the root cause analysis and the hypotheses. The procedure also needs to include how follow up is managed to ensure any resulting actions are implemented.
  • Additionally, the examination of materials and storage of evidence is also needed.
  • Finally, a post investigation review can be included in the procedure so that each incident investigation is reviewed to ensure its adequacy, how the investigation and outcomes could have been improved and the adequacy of the investigation process and procedures.

Supplementing all this is the need for a form to collect all the electrical evidence and a report writing template.

TRAINING

Trained electrical forensic investigators, to assist or take the lead investigator’s role, is important to ensure the ‘right’ outcomes are achieved.

Firstly, it is very important that the electrical investigators have the technical and investigative skills. PowerLogic’s training courses provide the best quality online or in-person courses in Australia for this. These include a one-day introductory course to a full three-day in-depth course, as well as a follow up Electric Shock Investigation Kit Course. Additionally, PowerLogic’s Electrical Incident Report Writing Course hone’s the skills learnt in the previously mentioned courses and develops the essential report writing skills to provide a high-quality report with high quality outcomes.

Daniel providing training in electric shock investigations

Not only does PowerLogic’s electric shock investigations courses prepare trainees for an investigation but they dramatically improve the trainee’s knowledge and skills for their everyday job.

Continuing professional development (CPD) is very important for electrical workers to stay on ‘top of their game’ as technologies are changing at an alarming rate and many haven’t done a lot of CPD since completing their initial training. PowerLogic courses provide this essential CPD in many areas.

Online training has become a must in this COVID-19 driven world and Powerlogic’s training centre provides an easy-to-use platform that facilitates remote learning. This online training is supplemented by trainee support over the phone, email, zoom and other online communication methods. Our online ‘Test RCD’ course allows users to trial our system at no cost.

EQUIPMENT

Electrical forensic investigators will need equipment to ensure all the available evidence is collected. Essential equipment includes a high- resolution camera and electrical test equipment. A video camera is also a good idea which may be the investigator’s mobile phone. The electrical test equipment may include a multimeter, RCD tester, insulation resistance tester, ohmmeter, loop impedance tester, proximity tester, electric shock investigation kit, etc. Much of this may be achieved with a multifunction tester.

Touch voltages being measured using a device simulating the human body

Electrical instrument calibration by a NATA laboratory is a good idea and calibration certificates could be included as an appendix in the incident report. Additionally, a calibration report could be obtained after the incident to ensure the meter was accurate for the incident investigation. This calibration report could include accuracy results at the measured levels for resistance, insulation resistance, voltage, etc, depending on the parameters measured.

Additional equipment may include witch’s hats, flashing lights, barrier tape, lockout kit, lighting, headlamps, raincoats, spare batteries, etc.

Loggers can be used to measure touch voltages where problems do not readily present

THE INVESTIGATION

Initially the investigation team needs to be established and conveyed to the incident site as soon as possible. Evidence gets contaminated and also changes over time. I was asked to provide guidance on an incident the day after the incident. On the day of the incident, the ground was wet from rain that day. The next day, the ground was dry due to sunshine and wind. This change provided totally different electrical conditions for the investigation. I was also asked to investigate an incident some twelve months after the incident – the evidence had dramatically changed in the intervening time and any relevance of the investigation to the incident may be contested.

An investigator was electrocuted some years back whilst investigating an electric shock off a roof and so hazard management is the most important part of the investigation. Initially a mental risk assessment will be needed to ensure immediate safety and then a more formal approach to hazard management will be needed and an induction process established for anyone allowed onto the site.

Much of the forensic investigation process has been mentioned in the previous Investigation Procedural Document section but the scene needs to be thoroughly and objectively examined, evidence collected, preserved and recorded.

Chris and Daniel collecting forensic electrical evidence after a shock incident

THE REPORT

Report writing is a skill that needs to be developed. PowerLogic’s Electrical Incident Report Writing Course helps to develop these skills so a high quality, easily read and understood report is provided for electrical qualified and non-technical readers.

The context of the report will depend on who the electrical forensic investigator is working for.

The investigator working for the company concerned will be seeking to provide high quality outcomes including those to prevent a further incident and to try to maintain the company’s reputation.

The investigator working for the electrical safety regulator will also seek to prevent further incidents, but their focus may be on prosecuting the company, managers and individuals involved and holding them accountable for their actions or lack thereof.

EVIDENCE STORAGE

Maintaining a ‘chain of custody’ is important for any physical evidence. This requires a process to be established in the company’s investigation procedure and training provided.

Appropriate storage is required to prevent contamination of the evidence. Bagging and sealing evidence might be required to prevent further corrosion of electrical connectors, for example. Electronic evidence, such as video and photos, will also need to be stored in accordance with the established procedure.

INVESTIGATION BLOOPERS

Investigators need to manage the onsite hazards and one investigator failed in his duty after the electrocution of a little girl. The incident was in the outback and as such, the police took charge of the investigation. The police had asked the local ‘poles and wires’ technician to accompany him for the investigation as it was thought that electricity may have been the cause of the death. The police asked the father of the little girl, what had happened. The father said that his daughter had touched the electrical appliance and he proceeded to show what had happened. In an instance, the father was also electrocuted. CPR was applied but to no avail. PowerLogic electric shock investigation courses highlight the responsibility of investigators to manage the electrical hazards on site – after all, they are the electrical experts on site.

An electrical investigation into an electrical incident involving network assets was led by non-electrical lead investigator. He did not involve his electrical investigators adequately and failed to take their advice regarding his report. Consequently, the wrong corrective and preventative actions were proposed. Incident investigations involving a team, need to be carried out as a team. (Remember there is no letter ’i’ in the word team.)

There have been so many cases where investigators list the touch voltage at an incident site using a high impedance multimeter. This may have little relevance to the touch voltage received by a person as their resistance is somewhat closer to 2,000 ohms than 10 million ohms of the typical multimeter. Double insulated electrical equipment has often been identified as being lethal and then replaced with a similar item in a similar condition. PowerLogic’s training discusses this issue in detail and trains how to make more relevant measurements and decisions.

I mentioned earlier that I had investigated an electric shock incident some twelve months after the incident as no one had proved the incident site was safe. The conditions had changed dramatically in the intervening time. The network provider had changed neutral connections on the mains as a precaution, the weather had changed from raining just prior to the incident to almost drought conditions when the investigation was carried out, the rain had caused problems with the home as the roof had been leaking, the roof had been replaced some months prior to the investigation. The coroner was critical of my report because of the delay in the investigation and the changed conditions. I had sprayed the wall with water as the wall was suspected as one contact point for the electrocution. Obviously, a spray of water is not the same as the wall being soaked because of days of rain. The owner obviously wasn’t going to allow me in the roof space with a water hose on at full strength.

One issue that often pops up is around the lack of evidence storage. As an example, a network provider rang to ask about how dangerous I thought a situation was. The incident had occurred at a school bus stop where a young lass had touched the metal pole number and received an electric shock. The problem was identified as a ‘leaky’ insulator at the top of the pole and so the insulator was replaced without haste. I asked what the test results were using the low impedance device designed to Figure 3 in AS IEC 60090 to a metal plate on the ground. The guys hadn’t carried out any testing as the fault was obvious. I asked them to send the faulty insulator to me and I would try to estimate how dangerous the situation might have been as I have some experience around the impedance of wood poles. Unfortunately, the insulator had gone with the rubbish that morning. This situation leaves the network business in a precarious position if a court case had resulted, and the evidence had been deliberately destroyed.

Evidence preservation for an incident is a legal requirement but this does not prevent any action required to assist or rescue a person. A young worker in the first two weeks of his employment was electrocuted. His employer dismantled the electrical switchboard before the authorities arrived on site to investigate. The electrical contractor received a sentence of seven years for manslaughter and perjury. Industrial manslaughter laws now allow for extensive jail terms and fines in excess of $10M.

CONCLUSIONS

Whilst preventing electrical incidents is the best option, electrical incidents can and do occur – the incident statistics are literally ‘shocking’. All incidents, including ‘near misses’ need to be appropriately investigated by trained and skilled investigators using established incident investigation procedures and appropriate equipment. Encouraging the reporting of ‘near misses’ without implications is therefore important.

Incidents need to be investigated as soon as possible to ensure all relevant evidence is collected before evidence contamination occurs. Risks at the incident scene need to be appropriately managed so all at the site remain safe.

Writing the report, carrying out the root cause analysis, developing the hypothesis and developing the corrective and preventative actions is important to prevent future incidents.The finals steps in an electrical incident investigation are to ensure all corrective and preventative actions are implemented and a post investigation review is conducted.

The finals steps in an electrical incident investigation are to ensure all corrective and preventative actions are implemented and a post investigation review is conducted.

Contact Chris or Daniel to discuss these matters further or to organise electric shock investigation training: powerlogic.com.au

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