#4 Arc Flash - Mitigation Solutions (after event)

Webinar #4 Arc Flash - Mitigation Solutions (after event comment)

Short summary from my side. Excellent questions in Q&A session from which I pick 3 and included it below in this article. If you have:

• more comments ??
• want to discuss things in more details ?
• I missed something important ?

Let me know in comments. Also your feedback ?? to webinar will be great information for me.

?? link to YouTube recording >>> https://youtu.be/oWKEtFjlpKY

? Q&A session :

All questions were answered during live session. Interesting questions below:

Q1:Explain about ERMS/ARMS

A1:It is called Arc Flash Reduction Maintenance Switch /Energy Reduction Maintenance Switch. In short words it is functionality of ACB trip unit that can be activated to reduce tripping time and threshold to min. values. We need to sacrifice selectivity temporarily but we do it in order to decrease arc flash energy (improve safety) for limited amount of time.

Q2: Why Diff protection sometimes won’t be the best solution?

A2: It is actually always good to have differential (ANSI 87) protection ( transformer, panel or generator) however in terms of arc flash it will be better to invest in to arc flash relay. However if we have diff protection installed it will improve protection (reduce AF energy).

Q3:All switchgears designed in accordance with IEC standard doesn't required additional PPE for operation. Is this correct understanding?

A3: Actually No. In general we can say that just being IEC tested assembly doesn't remove requirement for PPE (Arc flash and shock hazard). Arc Flash PPE requirements comes from calculated incident energy eg. above 1.2 cal/cm2 and specific task we are doing. For example measurements on live busbars will be considered high risk by NFPA70E and requires PPE and it doesn't matter is assembly is UL or IEC tested.

Bonus question : Would like to hear your experience on AF energy exposure calcs/ mitigation on DC systems (UPS 400/240VAC or 110 to 24VDC).

Bonus Answer : Yes I have it. I have in plan to make one webinar about DC arc flash as I had multiple projects with DC systems and I have few conclusion and general comments for such system results from arc flash point of view.

For the rest I recommend you to watch full webinar recording ???