PPE Nfpa 70e

[zog]

Ok, another question on the how far to go on the nfpa 70e. Is it ok to just turn off the 'main' THAT IS in the panel to do work on that panel?? It was my understanding that you could not do that, that you MUST turn off the power going to that panel to consider that panel deenergized. Is this correct or wrong??

Depends on the confuguration of the panel but in most instances your understanding is correct.

The tables address this, and again it is not so much the voltage but rather the available fault current and clearing time that affects the arc flash hazard. Look at your task tables, but for the most part you are right and that other guy is wrong. You work with some scary dudes.

 

[brother]

Depends on the confuguration of the panel but in most instances your understanding is correct.



The tables address this, and again it is not so much the voltage but rather the available fault current and clearing time that affects the arc flash hazard. Look at your task tables, but for the most part you are right and that other guy is wrong. You work with some scary dudes.

Well this panel was a 120/208 and had a main breaker in it. They turned the main breaker off but when they took off the dead front the feed to the main was hot and exposed, lugs and all. Even though the upper buss was dead when they were landing the breakers, I truely felt that this was in violation of nfpa 70e, even though I was told no its not.

When this hot work is going on, the proper ppe needs to be used, even though its 120/208. I hear people trying to justify the 'hot work' by using the 'infeasiblity' exception to quickly (ie critical loads).

All i have to say is that if a person made a 'mistake' or if something was left/loose in the panel when the cover was being removed, and shorted something out and the breaker tripped or worse yet exploded, then what 'couldnt' be shutdown is now 'shutdown'. I would say a good 98% of the hot work EVEN in Hospitals CAN be down with a 'shutdown'. Just use proper planning and tracing out of circuits.

 

[zog]

Well this panel was a 120/208 and had a main breaker in it. They turned the main breaker off but when they took off the dead front the feed to the main was hot and exposed, lugs and all. Even though the upper buss was dead when they were landing the breakers, I truely felt that this was in violation of nfpa 70e, even though I was told no its not.

In that case you would be correct, if the work is being done within the LAB ofthe exposed live parts.

When this hot work is going on, the proper ppe needs to be used, even though its 120/208. I hear people trying to justify the 'hot work' by using the 'infeasiblity' exception to quickly (ie critical loads).

Common problem, people confuse "infeasability" with "inconvenient"

All i have to say is that if a person made a 'mistake' or if something was left/loose in the panel when the cover was being removed, and shorted something out and the breaker tripped or worse yet exploded, then what 'couldnt' be shutdown is now 'shutdown'. I would say a good 98% of the hot work EVEN in Hospitals CAN be down with a 'shutdown'. Just use proper planning and tracing out of circuits.

Exactly.