“Considerations for flame resistant personal protective equipment (PPE), as a risk control measure, should only be adopted as a last resort principle."
Launch of our new factfile on arc flash risk management - IET Engineering Communities (theiet.org)
Z.
I suspect they did not mean you should wear a flammable shell-suit if at all possible, and PPE was a last resort if your outfit of the style above was in the wash.
Rather I'm pretty sure they meant that to rely on arc resistant clothing etc as the main defence is not as good as to try and reduce the risk of arcs as much as possible, and then being appropriately suited and booted as well.
I must admit I found the language a bit strange too, and some worked examples would be a good calibration, - how close for example does the unguarded flesh have to be to a worst geometry arc downstream of a 13A fuse to suffer a given degree of calorific illumination, or better, to suffer a burn of known severity.
In reality we know this (and have the wire cutters with a chunk missing to prove it ?) and it is a probably matter of a few inches for the 13A flex case.
And then a similar calculation for maximum let-through from a 100A house fuse and an 800A substation fuse - where I hope less of us have an experimental practical feel, but the closest approach distance before PPE becomes strongly advised is then a more useful figure.
References to 208V make me wonder if this is based on US-centric research, and then further to wonder if it really applies properly to likely UK fault levels.
Mike.
I suspect they did not mean you should wear a flammable shell-suit if at all possible, and PPE was a last resort if your outfit of the style above was in the wash.
Rather I'm pretty sure they meant that to rely on arc resistant clothing etc as the main defence is not as good as to try and reduce the risk of arcs as much as possible, and then being appropriately suited and booted as well.
I must admit I found the language a bit strange too, and some worked examples would be a good calibration, - how close for example does the unguarded flesh have to be to a worst geometry arc downstream of a 13A fuse to suffer a given degree of calorific illumination, or better, to suffer a burn of known severity.
In reality we know this (and have the wire cutters with a chunk missing to prove it ?) and it is a probably matter of a few inches for the 13A flex case.
And then a similar calculation for maximum let-through from a 100A house fuse and an 800A substation fuse - where I hope less of us have an experimental practical feel, but the closest approach distance before PPE becomes strongly advised is then a more useful figure.
References to 208V make me wonder if this is based on US-centric research, and then further to wonder if it really applies properly to likely UK fault levels.
Mike.
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