Arc flash level

[victa1288]

I just started arc flash study recently and I'm not familiar with IEEE1584. Does the catgory have anything to do with relay setting level. In our case, arc flash levels are Cat. 0,1,2. I don't think we should worry about the arc-energy. But I don't know if there are any standards about this.

Thank you.

 

[wbd]

First, I don't think you should be doing any arc flash studies without being familiar with IEEE 1584. In order to understand what you are analyzing, you need to be familiar with the concepts and background. It's like saying, I'm doing short circuit fault analysis but am not familiar with symmetrical components.

You should also familiarize yourself with NFPA 70E, if you're in the USA.

You always try to lower the arc flash to the lowest category possible. If you knew IEEE 1584, you would know that the arc flash categories are based providing protection so that the wearer would get no worst than an exposure of 1.2 cal/cm2 on bare skin. This is a survivable 2nd degree burn.
Lower the arc flash hazard can be accomplished by changing relay settings, installing current limiting fuses, etc.
I assume you are using some sort of software to perform the study. Be aware that some software does not take into account current limiting fuses and you must perform those calculations by hand using the formulas in IEEE 1584.

Please educate yourself on IEEE 1584 before doing the study. It feel awful knowing that someone got hurt because the time was not taken or dollars spent to buy, read and understand the basic document for arc flash hazards.

 

[Zogzog]

This statement "Does the catgory have anything to do with relay setting level."

And this statement "I don't think we should worry about the arc-energy."

Tells me you should not be the one doing this study until you have had some training.

 

[victa1288]

Thank you for your suggestions. Unfortunatelly, our employer doesn't want to buy many IEEE books which i think are useful. So possibly I have to buy some byself.

 

[dpc]

I'd start with NFPA 70E. It's a lot less expensive than IEEE 1584 and gives you information regarding the Hazard/Risk Categories.

A Google search will provide a lot of links on arc-flash.