My name is Günther Müller, I have 20 years of experience in electrical engineering, and I work for a Consultant in Germany. I currently work on the extension of the electrical installation of a site in Europe, owned by a large American industrial group.
In this context, we were asked to evaluate the risk related to Arc Flash, in compliance with NFPA 70E standard and the IEEE1584 calculation methodology. It was the first time I had to do this evaluation, as this is a US standard which I did not know about and which has no equivalent here.
First, we had to make the audit of the existing installation, and the dimensioning of the extension. Then, we had to make the estimation of the Arc Flash risk level for every electrical switchboard, in order then to choose the category of PPE (Personal Protection Equipment) which electrical maintenance people should wear when operating on or near these equipments.
But now I really wonder: will this really help to protect the maintenance operators against arc flash risks?
First, I doubt it is realistic in practice to ask maintenance teams to wear different types of protections depending on the switchboard they work on. And I doubt they will even wear these protections, considering they seem to make it really hard to work with (impossible to do precise work with your fingers, lack of visibility, heat, etc …)
Second, I wonder why the standard calculates the Arc Flash energy at a distance of 18 inches (~50 cm): what about the possible damages to the hands and arms of a worker who is at the origin of the short-circuit, for example due to a mistake when checking that the power is down?
Third, as the results give a PPE category = 0 for 400V switchboards with a short-circuit level of 20kA, isn’t there a risk that some maintenance people will consider that there is no risk, when in reality if they are at the origin of a short-circuit with their tool they will be at minimum seriously burnt?
Also, as I found this standard somewhat questionable, I searched for more information about it on the web, and found this article and survey done in Australia and published in Industrial Electrix issue of April/June 2011, which I found on this website:
(click the link and go to page 44)
This is an abstract from the article:
So I even wonder if the calculations and estimations of this IEEE 1584 are realistic, or if the real risk is in some cases underestimated, which makes the standard almost worse than no standard at all, as people following the rules will feel safe with their PPE when they may risk more than 2nd degree burns.
Finally, even though my first thought was that it was a good thing there was an existing standard in the US, I feel that the current situation worldwide is:
* in the US, there is an existing standard but it is potentially dangerous
==> Contradict me if you disagree
* outside US, there is no Arc Flash risk specific analysis or recommendations
==> Tell me if you know about existing surveys or standards in your countries