Arc Flash disagreement
Arc Flash disagreement
(OP)
I am having a disagreement on NFPA70E and IEEE1584-2002 with a collegaue. He believes that arc flash boundaries apply AT ALL times (i.e. no maintenance, inspection, or electrical work). I believe that the arc flash requirements only apply while performing 'live' electrical work.
Can I please get your opinion - have I missed something in the literature or my understanding?
Can I please get your opinion - have I missed something in the literature or my understanding?






RE: Arc Flash disagreement
However it was also noted that an arc flash can occur at any time (Animals, water, insulation failure) so you can be exposed to an arc flash if you are in the boundary doing nothing, but the term "Interacting with the equipment" was stressed.
RE: Arc Flash disagreement
RE: Arc Flash disagreement
This is somewhat vague in NFPA 70E, probably intentionally.
RE: Arc Flash disagreement
RE: Arc Flash disagreement
RE: Arc Flash disagreement
RE: Arc Flash disagreement
RE: Arc Flash disagreement
RE: Arc Flash disagreement
All the discussion of PPE when you are not working live on electrical equipment are meaningless.
PPE offer "reasonable" protection only for "burn" injuriesfrom a arc flash blast. That too only to limit to a second degree which is most painful. PPE are not even intended to offer protection against flying debris or objects. So while boundaries may exist, PPE is only required or useful when interacting with "open" live equipment.
The type of risks that exist or injury that can occur when the gear is enclosed and blast occurs inside and one happens to be just walking by the gear, CANNOT be reduced by a PPE nor PPE are designed for it.
So all the discussion of PPE when you are not working live on it are meaningless.
RE: Arc Flash disagreement
1. PPE is required for interacting with the subject eqpt. This interaction could include operating breakers.
2. PPE is not required when walking by or standing by exposed eqpt even though it is within the arc flash boundary.
I have seen a situation in an old power plant that has open 480V, delta, copper bus bars for the bus with breakers directly bolted to the bus work with cable on the other side. These breakers are just behind a mesh screen with the bottom 3 ft completely open and all the bus work open about 10 feet off the ground. The plant operator has to stand with his back to this, about 6 feet away to synch and close in the generators attached to the bus.
The fault current on these buses is around 37 - 51kA, depending on generation. This put the AFH from Cat 3 to extreme hazard.
RE: Arc Flash disagreement
1. PPE is required when anyone is interacting with the subject equipment.
2. PPE is not required when walking by or standing by exposed eqpt even though it is within the arc flash boundary; unless someone else is interacting with the equipment.
It is not enough that the guy performing the task wear the PPE; everyone else needs to suit up or leave the boundary area.
RE: Arc Flash disagreement
I live under a different set of rules awhere limits of approach are set for all access to area. So this conversation is acedemic to that but lets take a step back - You & I have a duty of care to all in our charge & those around us.
If we dont have enough ppe for the tourists then they walk away. It is really hard to rebuild people & there is only one recorded case of resurection (and half the world doubts that).
SO I would (and probably am) known for being cautious and I suggest that life style to all playing with HV or looking to "save a bit".
Anyway enjoy the journey & grab the memories
Don