Managing Arc Flash Risk - Best Practice for Asset & Safety Management

Our very own Alan O’Kelly and Esté Vorster took to the stage at yesterday’s Substation Safety Conference to present on the very interesting topic of Managing Arc Flash Risk – Best Practice for Asset & Safety Management.

For anyone who missed it here is a brief synopsis of what was discussed.

Kicking off the session Alan talks us through what is arc flash, a basic understanding of the hazard, and some mitigation solutions.

“Arc Flash is defined as a flashover of electric current through air (or what used to be air) from one exposed live conductor to another or to ground. The current passage is through the vapour of the arc terminal material and ionised air”

Alan O'KellyDirector

He then continues to detail the known and unknown components of an arc blast, the damage each can do, and what can cause an arc flash.

Common Causes of Arc Flash

Sometimes referred to as bolted faults, can include:

  • Accidental contact with live exposed parts can initiate arc faults
  • Tools dropped accidentally can cause a momentary short circuit, producing sparks and initiating arc flash events
  • Dust and impurities on insulating surfaces can provide a path for current, allowing it to flashover and create arc discharge across the surface.
  • Corrosion of equipment parts can provide impurities on insulating surfaces. Corrosion also weakens the contact between conductor terminals, increasing the contact resistance through oxidation or other corrosive contamination

Drawing his section to a close Alan finished with the control measures that can be put into place to prevent or reduce the possibility of an arc blast. This included an example of where we helped a client reduce their incident energy levels from 42.5 cals/m2 to 12 cals/m2 by conducting a survey and introducing new protection settings.

Following on from Alan,  Esté addressed asset and safety management and how they tie in with electrical models and model management concerning arc flash.

“For us to supply you with the Arc Flash incident energy levels or the “cals” Alan mentioned earlier. We first need to create the most accurate electrical model of your system.
The process begins with gathering all your Single Line Diagrams, starting from your supply from the utility or any alternative source down to the MCCs and distribution boards. This will be the foundation of our model.
Building on that we gather utility, transformer, generator information as well as any other sources of energy.”

Esté VorsterPower Systems Engineer

Asset Management and Master Records

This model is then used for asset management and creating master records in a centralized system that can be managed and updated as the model grows and changes.

For sites where there can be multiple contractors performing work, sometimes even at the same time, there can be confusion, time delays, data loss, or errors being made due to a lack of documentation. Having master records eliminates this and ultimately provides a safe working environment with correct and current data for employees and contractors.

Finishing up the presentation Esté highlighted the additional benefits of having a model aside from arc flash and asset management. These included:

  • Data is easily accessible – no more digging through years of documents, emails, going back and forth looking for cable details, etc.
  • Design validation – when expanding or adding new equipment
  • Protection of key assets can be reviewed and verified resulting in improved reliability.
  • Safety Management – With up-to-date arc flash results, simulated in all operating scenarios, you can ensure when maintenance or operations take place that safety is always the top priority by protecting personnel, and choosing the correct PPE or mitigation strategies.
  • ISO 45001 requires an employer to provide a safe work environment, including risk assessments when work is performed. Having arc flash results reflecting your network easily accessible, you would be audit ready.
  • Fault finding investigations
  • Load Analysis – Performing load analysis can aid in verifying network expansion plans.
  • Switching Planning – this can be made easier by having the arc flash results under different scenarios, work at a specific location can be performed in such a way as to avoid high incident energies if possible.

We have to say a big thank you to Powerpoint Engineering for hosting the great event and asking us to speak at it. It was so nice to get in front of people again and we look forward to the next event.

If you have any questions on this topic or wish to discuss the possibilities at your facility please give us a call at +353 1 8105032 or send Alan or Esté a mail at