If you're trying to decide whether or not to have an arc flash study completed on your facility then there are a few major considerations you need to take into account. Also, you need to understand that this is not only an exercise in engineering but more importantly, an exercise in hazard identification. Which for any organization should be taken very seriously.
In this article I'll break down just what the arc flash study does for you and maybe a little bit about the technical side... but the point I want to drive home is the importance this has on your electrical workers' everyday activities.
So what is an arc flash study?
First of all, you need to understand that an arc flash is essentially an explosion that has a certain amount of heat energy associated with it. an arc flash study, in it's simplest form, is an engineering exercise which produces labels that identifies how much heat energy is available at any particular point in your electrical system. Sometimes there is enough energy to roast a marshmallow and sometimes the amount of heat would rival the surface of the sun for the hottest place in our galaxy. Without doing the study you just don't really know.
What's the alternative?
There is an alternative... or maybe a couple, but the most commonly used is called the "table method". You can find these tables in the electrical safety standards NFPA70E or CSAZ462 but the trouble is they are often not used properly and still require a little bit of electrical mathematics (that seems to be the biggest issue with them). The other thing is that you still don't really know for sure what the energy levels are. Using the tables gives you an estimate, albeit a conservative one, but then this might lead to wearing too much PPE.
Long story short... stick with the arc flash study.
What are the associated costs?
The cost of having an arc flash study done is probably the main reason people look to the alternatives... you've got to hire engineers (god forbid) to do the work and there is a substantial overhead because the engineers are likely using expensive software to do the calculations. It might hurt in the beginning but once you have the labels on then you now have a system in place that is easy to use and much more accurate than the table method... in my opinion well worth the cost.
And I'll be honest, I've recently changed my opinion on this. Knowing that arc flash studies do cost more than the alternative I usually recommended trying the table method first if an organization was a little leery of forking out the cash. But through experience and working with these companies I've now decided that the easiest and most effective way to identify your electrical hazards is by completing an arc flash study.
The biggest benefit is the simplicity
Your electricians will thank you. By having the arc flash study completed and labels placed on all your equipment you take the guesswork out of it. You make hazard identification crystal clear and that means your electricians can focus on the actual task at hand not trying to decipher how much heat energy to prepare for.
If you're on the fence then hopefully this artcle helps you decide what side you want to get down on... the side of doing the arc flash study. Simplify your electrical safety program by making hazard identifiaction a non-issue. Make things very clear for the electricians (and all workers for that matter) by having proper arc flash labels installed on all your equipment.