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 Post subject: multiple labels
PostPosted: Wed Dec 09, 2009 7:45 am 
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Joined: Mon Nov 05, 2007 10:10 am
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Location: Mid-West
One switchgear/switchboard/panelboard with multiple sections, if the main breaker is located in the first section of the equipment is it acceptable to have a separate label for the adjacent "downstream" sections of the equipment? ex. front accessible switchboard section#1 bussed pull / termination section, section#2, main breaker / fuse. section #3 distribution sections), the arc flash label indicates the hazard with respect to time, current, and clearing time of the upstream OCPD (fuse / brkr.) my question if an electrician is working on section #3or#4 would it be acceptable to place an arc-flash label based on the equipment OCPD TCC characteristic? if you are not exposed to the line side of the main or the incoming cables? if you were to work on section#1or#2 you would have to dress for the potentially larger hazard of the next upstream device not locally in the equipment? does this make any sense? thanks for everyone's options / help.


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PostPosted: Wed Dec 09, 2009 8:03 am 
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Joined: Thu Jul 19, 2007 7:54 am
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Location: St. Louis, MO
This has been discussed / debated quite a bit.

If the main breaker is in a section by itself, and is segregated from the other sections on the line and load side, and the associated line side buswork / cabling is also segregated, then it would be acceptable to place separate labels on the main breaker and incoming sections, and on the downstream sections of the switchgear.
This will usually result in lower arc flash ratings for the load sections of the switchgear, making it easier to operate. The main breaker will likely be a high rating, and it may not be acceptable to operate this breaker from the front of the switchgear at all.

The key to this approach is Training. Make sure the electricians and operators understand what the labels mean and why there are multiple labels on the switchgear.


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PostPosted: Wed Dec 09, 2009 8:37 am 
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Location: Mid-West
multiple sections is the key...

I agree training is the key. I just could not understand if I had a switchboard and was working in the third section where with the cover removed I am not exposed to the line side of the main OCPD and protected by the TCC of the main OCPD why should the electrician be forced to wear the "moon-suit" and create a possible hazard due to "overprotection" but yes if you were to access the main compartment you would have to dress for that hazard but in many cases I could see a cat.3 on the main and a 1 on the adjacent sections making it a much more practical working environment.


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