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Question(s) on NFPA 70E

M

mshields

Silver Member
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Aug 9, 2011
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105
Location
Plymouth, MA
Table 130.7©(9) in NFPA 70E defines, among 3 other things, what the Hazard/Risk Category is for certain tasks on certain types of equipment. When does one use this table. e.g. I am doing work at a facility where a full set of studies (short circuit, coordination and arc flash were recently performed and the approrpiate Arc Flash stickers with PPE level have been installed on all panelboards. Now, let's say that you have a 480Y/277V panelboard with a PPE level 3 according to it's sticker.

Table 130.7©(9) tells me that the PPE level varies with the task. So e.g. if you are operating a CB with the covers on, Hazard/Risk Category is 0. So what level of PPE gear should the worker planning on operating a breaker with the cover on, get suited up for? Category 0 or Category 3.

Also, what would Performance of Infrared thermography and other non - contact inspections outside the restricted approach boundary have a Hazard Risk Category of 1 when actually operating a breaker has a risk category of 0. You would think that touching and operating the equipment would have more stringent requirements than something requiring no contact at all?
 
mshields said:
Table 130.7©(9) in NFPA 70E defines, among 3 other things, what the Hazard/Risk Category is for certain tasks on certain types of equipment. When does one use this table. e.g. I am doing work at a facility where a full set of studies (short circuit, coordination and arc flash were recently performed and the approrpiate Arc Flash stickers with PPE level have been installed on all panelboards. Now, let's say that you have a 480Y/277V panelboard with a PPE level 3 according to it's sticker.Table 130.7©(9) tells me that the PPE level varies with the task. So e.g. if you are operating a CB with the covers on, Hazard/Risk Category is 0. So what level of PPE gear should the worker planning on operating a breaker with the cover on, get suited up for? Category 0 or Category 3.
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The tasks in T130.7©(9) are based on standard configurations and conditions. Therefore, since the Hazard/Risk Categories in the table are assumed and based on experience, I get the impression that Cat 0 is based on the fact that covers on will contain a great deal of the calculated indecent energy. Also bear in mind that Cat 0 still requires the PPE listed in T130.7©(10).

Also, what would Performance of Infrared thermography and other non - contact inspections outside the restricted approach boundary have a Hazard Risk Category of 1 when actually operating a breaker has a risk category of 0. You would think that touching and operating the equipment would have more stringent requirements than something requiring no contact at all?
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Again we are talking covers on or off. The restricted boundary is only 1' for 480V gear as per T130.2©. I wouldn't want to be that close with covers off during an arc-flash. I like my face.

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Thanks Chris but let me try another example on for you. T130.7©(9) indicates that if you are working on energized electrical conductors and circuit parts including voltage testing on a panelboard or switchboard rated greater than 240 and less than 600V (so let's say 480V) the the HRC is 2 (which by the way has an asterik which I cannot find a Key for - what does the asterik mean?). So here we're talking about with the cover off and if my panel has a label that says PPE 3, which do I go by?

Also, what does 70E say about operating the buttons say on a meter. If that meter is on equipment with HRC of 3 or 4, do I have to put on the space suite to toggle between phase A, B and C current for example?
 
I don't know that I'd reach into a hot panel without complete PPE ... when I saw a fire pump controller blow up, the electrician geared up fully before going into the room (it was a bad board, not the electrician's issue). Loud and scary.
 
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