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 Post subject: ARC Flash rating for electric meter removal
PostPosted: Wed May 13, 2009 12:56 pm 
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I am the safety director for a company that replaces and installs electric meters for utility companies across the US. I have been beating my head in the wall over this Hazard Risk Assessment. I have no clue where to start since it varies so much from one area or house to the other. I at this point require my men to wear PPE rated at 8 Cal for < 240 and 12.4 Cal for <480. I have read a few threads on here that state I should require atleast 20 Cal for my 3 phase installers. Can anyone shed some light on this turmoil I have here? :confused:


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PostPosted: Fri May 15, 2009 6:03 am 
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I suppose no one has had a situation like this before. I have seen alot of talk about single and three phase meters on these forums. I am just having a hard time with analyzing the hazard risk factor and I thought maybe someone could give me a worst case scenario for ARC flash rating on a a single phase and three phase


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PostPosted: Fri May 15, 2009 7:45 am 
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You are not going to be able to do single phase. You can treat the mete socket as a bus in order to determine the fault currents in your modeling, I suppose.

I do know they make these:
http://www.rauckmanutility.com/homemeterpuller.htm


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PostPosted: Mon May 25, 2009 6:22 pm 
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Location: Spartanburg, South Carolina
If the work is on utility meters, then it is covered by NESC. The NESC has a general 4 cal/cm² for systems below 1000V if an incident energy (IE) analysis is not made, and a clothing system to match the IE if it is calculated. It doesn't specify what method to use if an analysis is done.

The problem is, if you use IEEE-1584 for low voltage metering fed by large transformers with no secondary protection, you will calculate IE much greater than 4 cal/cm² and greater than 40 cal/cm² in many cases. It is generally recognized that 4 cal/cm² is not adequate in many cases. There are proposals to add a table to the next NESC that would use 20 cal/cm² for 480 volt systems.

See the NESC section of this forum for more discussion.


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PostPosted: Thu May 28, 2009 5:52 am 
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Yea I have seen the meter puller before but they are costly. I had heard from some utility companies that a small ARC Flash could come from a meter base carrying 240 volts or less. I already make my guys wear gear rated at 8ATPV just in case. I appreciate the info. If you know of anywhere I can see testing of a 240volt meter base please let me know


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PostPosted: Thu May 28, 2009 5:56 am 
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Yea I have made my guys working on 240volts or less wear PPE rated at 8 cal/cm just in case. I plan to move my employees working with 480 volts into the 20 cal/cm as soon as possible. Thanks for the info. Jghrist


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