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| Dead Cabinet? https://brainfiller.com/arcflashforum/viewtopic.php?f=2&t=111 |
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| Author: | Rick [ Thu Apr 17, 2008 1:38 pm ] |
| Post subject: | Dead Cabinet? |
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 |
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| Author: | WDeanN [ Fri Apr 18, 2008 11:59 am ] |
| Post subject: | |
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. |
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| Author: | Rick [ Tue Apr 22, 2008 6:10 am ] |
| Post subject: | |
I found the same OSHA clarification and had the same interpretation as you. Thanks for the reply. |
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