It is currently Mon Dec 11, 2017 10:12 am



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Dead Cabinet?
PostPosted: Thu Apr 17, 2008 1:38 pm 
Offline

Joined: Thu Apr 17, 2008 12:36 pm
Posts: 3
Location: Clarksville, Tn
I have a question about when a machine control panel is considered safe. My background is 22 years in maintenance of industrial equipment but because I am working on my degree in EH&S I have been assigned to the team developing our NFPA 70E compliance program. I will use one particular machine that is very common in our plant as the example. It is an industrial CNC lathe with a large control panel fed with 480V, 3 phase from a Bus plug fused at 200 amps. I understand that to work in this cabinet we would turn off the disconnect but still be required to use Cat 2* flash protection to test for voltage. My question is this; At this point is the panel considered electrically safe as far as NFPA 70E is concerned. Everything on the load side of the disconnect is dead but the line side is still hot. Would it matter if the line side is guarded to prevent possible contact? We want to provide the proper protection to our technicians, but if they don’t have to work in all of the gear at this point that would be great. I am trying to learn as much about this as I can in a short amount of time.
Thanks for your help,
Rick


Top
 Profile Send private message  
Reply with quote  
 Post subject:
PostPosted: Fri Apr 18, 2008 11:59 am 
Offline
Sparks Level

Joined: Thu Jul 19, 2007 7:54 am
Posts: 201
Location: St. Louis, MO
Greetings from Middle TN!
I would think that IF the line side is suitable guarded and shielded, then after voltage testing, the cabinet would be in an electrically safe position. I will qualify this by saying, there's no telling what the lawyers and OSHA will do to you, though, if there is an incident.
It may help a little, but doesn't direction answer you question, here:
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=25973

Move the disconnect to a separate compartment, if possible.


Top
 Profile Send private message  
Reply with quote  
 Post subject:
PostPosted: Tue Apr 22, 2008 6:10 am 
Offline

Joined: Thu Apr 17, 2008 12:36 pm
Posts: 3
Location: Clarksville, Tn
I found the same OSHA clarification and had the same interpretation as you. Thanks for the reply.


Top
 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
© 2017 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883