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Customer claiming they cannot operate a circuit breaker?
https://brainfiller.com/arcflashforum/viewtopic.php?f=2&t=5217		 Page 1 of 1
Author:  danocap1982 [ Tue Dec 03, 2019 9:30 am ]
Post subject:  Customer claiming they cannot operate a circuit breaker?
Please help - a customer sent me this note (below). I cannot find in 70E where it states these upper limits with respect to breaker operation. It does not make sense to me as IE is energy with respect to the distance over a specific time. Why would it have relevance to whether or not a breaker can be operated? Bear in mind that this is a new installation. Am I missing something?


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• The latest revision of NFPA 70E does allow for opening and closing a breaker above 40 cal if the proper maintenance has been done. However, this has an upper limit around 70-75 cal. NFPA 70E guidance does not allow for operation of the current equipment in its operational state because it is well above the upper limits identified in NFPA 70E
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Author:  danocap1982 [ Wed Dec 04, 2019 7:00 am ]
Post subject:  Re: Customer claiming they cannot operate a circuit breaker?
I think I have more information. The comment from the customer I now understand to mean that they can not operate the breaker locally (while standing in front of the switchgear). This is different than my original understanding that they said they could not operate it at all.

That said, I still cannot find any NFPA 70E upper limit of 70 - 75 Cal/cm^2 as they state in NFPA 70E 2015 or 2018...?
Author:  mayanees [ Wed Jan 15, 2020 12:32 pm ]
Post subject:  Re: Customer claiming they cannot operate a circuit breaker?
They can operate the breaker locally without PPE if the equipment is in "Normal" condition as defined by 70E-2018 Table 130.5(C).
That task is listed in the same table on page 70E-26.
Author:  Jim Phillips (brainfiller) [ Thu Jan 16, 2020 11:03 am ]
Post subject:  Re: Customer claiming they cannot operate a circuit breaker?
danocap1982 wrote:
I think I have more information. The comment from the customer I now understand to mean that they can not operate the breaker locally (while standing in front of the switchgear). This is different than my original understanding that they said they could not operate it at all.

That said, I still cannot find any NFPA 70E upper limit of 70 - 75 Cal/cm^2 as they state in NFPA 70E 2015 or 2018...?


A bit of additional info to go along with the comments from Mayanees. NFPA 70E does not specifically call out 40 cal/cm^2 for operating a circuit breaker. This likely was referencing the informational note about de-energize above 40 cal/cm^2 which was deleted in the 2018 edition. There isn't a reference to 70-75 cal/cm^2 in NFPA 70E
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