The small OEM that I work for is a bit behind the times. The “powers that be” have a consultant coming in that is supposed to be training us on arc flash safety. I am always thankful for increased safety measures and awareness!
I have an older copy of NFPA 70E and been doing some reading and research on my own so I can ask intelligent questions.
As I understand it, an arc flash hazard analysis determines the protection boundary and therefore the required PPE. But if an analysis is not done, it appears that one can simply refer to table 130.7(C)(9)to determine the appropriate Hazard/Risk Category (HRC) and then choose the proper PPE from tables 130.7(C)(10) and 130.7(C)(12) based on the previously determined HRC.
For reference, most of our equipment has a mixture of 480 VAC (for drives, motors, resistance heating) down to 24vdc (for inputs, outputs, instrumentation etc.). On small projects, it is impossible to provide separate enclosures for high and low voltage due to space requirements. As I read the tables, it appears that we would generally end up with hazard risk category 2. I say this because of the voltage and the need to perform various tests (typically with multimeter) on energized components.
My concern in all this is that the consultant and “powers that be” may somehow try to implement more protection than necessary ("just to be on the safe side") which would adversely affect efforts by engineers and technicians as they debug new equipment.
My GUESS is that the tables are VERY conservative and likely require more and/or better PPE than an actual arc flash hazard analysis would support for our facility. Does anybody have any experience with this? For instance, is it possible that a proper analysis could reduce the HRC from 2 to 1 or perhaps a 2 down to a 0?
My reason for asking is that I think the company is balking at doing the actual arc flash hazard analysis for the facility due to what is perceived as too high of cost.
I have an older copy of NFPA 70E and been doing some reading and research on my own so I can ask intelligent questions.
As I understand it, an arc flash hazard analysis determines the protection boundary and therefore the required PPE. But if an analysis is not done, it appears that one can simply refer to table 130.7(C)(9)to determine the appropriate Hazard/Risk Category (HRC) and then choose the proper PPE from tables 130.7(C)(10) and 130.7(C)(12) based on the previously determined HRC.
For reference, most of our equipment has a mixture of 480 VAC (for drives, motors, resistance heating) down to 24vdc (for inputs, outputs, instrumentation etc.). On small projects, it is impossible to provide separate enclosures for high and low voltage due to space requirements. As I read the tables, it appears that we would generally end up with hazard risk category 2. I say this because of the voltage and the need to perform various tests (typically with multimeter) on energized components.
My concern in all this is that the consultant and “powers that be” may somehow try to implement more protection than necessary ("just to be on the safe side") which would adversely affect efforts by engineers and technicians as they debug new equipment.
My GUESS is that the tables are VERY conservative and likely require more and/or better PPE than an actual arc flash hazard analysis would support for our facility. Does anybody have any experience with this? For instance, is it possible that a proper analysis could reduce the HRC from 2 to 1 or perhaps a 2 down to a 0?
My reason for asking is that I think the company is balking at doing the actual arc flash hazard analysis for the facility due to what is perceived as too high of cost.