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what PPE needed question?
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Author:  Justa_Sparky [ Sat Jun 14, 2008 12:15 pm ]
Post subject:  what PPE needed question?

The more I read the more confused I get.

Okay here is an example I am troubleshooting an e-stop circuit in a two bay panel. On the disconnect bay of the panel is all the 480 volt motor starters and 480 volt terminals. On the other bay are the plc and 120 volt AC and 24 volt DC control circuits.

The arc flash study shows the panel as a category 0.
With an arc flash boundary (AFB) of 5 inches, with a 0.3 cal/cm2 calculation.

My understanding is to troubleshoot the ac control with a VOM all I need is shock protection (rubber gloves) because I will not be in the AFB. But if I get within 5 inches while troubleshooting of the 480 volts Arc Flash PPE will be needed.

But what if I am 9 inches from 480 volts operating a selector switch that is mounted in side the panel? Do I need rubber gloves and a long sleeve shirt on?

Thanks for the help
Steve

Author:  Zog [ Sat Jun 14, 2008 7:00 pm ]
Post subject: 

Justa_Sparky wrote:
But what if I am 9 inches from 480 volts operating a selector switch that is mounted in side the panel? Do I need rubber gloves and a long sleeve shirt on?

Thanks for the help
Steve


Yes, because you are within the RAB for 480V which is 12"

All your other assumptions earlier in your post were correct.

Author:  Justa_Sparky [ Fri Jun 20, 2008 8:23 am ]
Post subject: 

Thanks for the reply

So a long sleeve shirt is needed for shock hazard not just arc flash?

Thanks again
Steve

Author:  Zog [ Fri Jun 20, 2008 10:15 am ]
Post subject: 

Justa_Sparky wrote:
Thanks for the reply

So a long sleeve shirt is needed for shock hazard not just arc flash?

Thanks again
Steve


No, sorry I missed the LS shirt part of your question. Any part of your body (Or conductive object you are holding) that crosses the RAB needs to be insulated for the voltages present.

The FR (Or natural fiber for HRC 0) clothing is all for Arc Flash protection.

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