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 Post subject: Opening or closing a CB, is it a normal operation?
PostPosted: Sun Jan 17, 2021 10:57 am 
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Joined: Sat Apr 04, 2009 9:50 pm
Posts: 114
Location: San Antonio, TX
110.4(D) uses the concepts of:

1. Normal operating
2. Normal operation

The concept of normal operating requires six conditions to be satisfied, and are very clearly stated.

The concept of normal operation is not defined.

Table 130.5(C) states that operating (aparently concept 2) a CB in equipment that is operating normally (concept 1), does not have a high likelihood of occurrence of arc flash events.

Assuming that the equipment is operating in a normal condition (concept 1), is operating a breaker considered a normal operation (concept 2) as stated in 110.4(D)?


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Wed Jan 20, 2021 12:02 pm 
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Joined: Mon Sep 17, 2007 5:00 pm
Posts: 1561
Location: Scottsdale, Arizona
RECS wrote:
110.4(D) uses the concepts of:

1. Normal operating
2. Normal operation

The concept of normal operating requires six conditions to be satisfied, and are very clearly stated.

The concept of normal operation is not defined.

Table 130.5(C) states that operating (aparently concept 2) a CB in equipment that is operating normally (concept 1), does not have a high likelihood of occurrence of arc flash events.

Assuming that the equipment is operating in a normal condition (concept 1), is operating a breaker considered a normal operation (concept 2) as stated in 110.4(D)?

My usual disclaimer - this is not any official interpretation since I'm prohibited from doing that but...

The two terms are used together as you point out. Normal Operation (action) is permitted when a Normal Operating Condition (status) exists. The way I look at it is one is the action you wish to take and the other is the status required before taking that action.

The 2021 Edition of NFPA 70E tried to clarify a similar situation with the Electrically Safe Work Condition. In one place it is the "condition" and in another place it is the "act of" creating the condition. Great idea for public input to the 2024 Edition!


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Wed Jan 20, 2021 12:15 pm 
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Joined: Sat Apr 04, 2009 9:50 pm
Posts: 114
Location: San Antonio, TX
Jim:

Can you please expand on your answer, because I still do not have your opinion (not official NFPA 70E opinion) if opening or closing a breaker is considered a normal operation?

Also, I posted a question regarding the exceptions for the EEWP that seem illogical. I have posted this question before and have received no confirmation or explanations of why they are there because they do not make any sense. I would really appreciate it if you can give me your opinion.

Thanks.


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Wed Jan 20, 2021 4:29 pm 
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Joined: Mon Sep 17, 2007 5:00 pm
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Location: Scottsdale, Arizona
RECS wrote:
Jim:

Can you please expand on your answer, because I still do not have your opinion (not official NFPA 70E opinion) if opening or closing a breaker is considered a normal operation?

Also, I posted a question regarding the exceptions for the EEWP that seem illogical. I have posted this question before and have received no confirmation or explanations of why they are there because they do not make any sense. I would really appreciate it if you can give me your opinion.

Thanks.

Oops, got so caught up in my explanation I forgot your main question - sorry.

I believe the answer is yes. This goes back to 2009 when NFPA 70E added the word "interaction" to the arc flash hazard. People were wondering if that meant a simple CB operation like you describe requires PPE.

However, my comment here should not guide your action - someone on that end will need to make the determination. (creative disclaimer :D )

However, about a week ago, I asked the "Question of the week" about do people wear arc rated PPE even when the incident energy is below 1.2 cal/cm2 where arc rated PPE is not required. Many said yes, they wear it anyway. That same logic could apply here for some.


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Wed Jan 20, 2021 10:04 pm 
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Joined: Sat Apr 04, 2009 9:50 pm
Posts: 114
Location: San Antonio, TX
Thanks so much!

Any thoughts about the inconsistent exceptions for EEWP?


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Mon Feb 22, 2021 7:03 am 
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Joined: Tue Jul 01, 2014 8:40 am
Posts: 99
Hi All, Greetings from a cold Snowy Ontario Canada. Here in CSA Z462 we define normal operation as: Normal operation — to cause electrical equipment to function within the manufacturer’s and engineered system’s specified design and operational parameters. So yes I would say operating a CB is a normal operation. Different of course from "Normal Operating Condition" which si defined in both Z462 and 70E. I hope that this is of some help


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 Post subject: Re: Opening or closing a CB, is it a normal operation?
PostPosted: Mon Mar 01, 2021 8:20 am 
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Joined: Sun Sep 23, 2007 5:00 pm
Posts: 127
Location: Calgary, Alberta, Canada
An employer's Electrical Safety Program would include a Risk Assessment Procedure it would advise that:

1. No arc flash PPE is required when operating electrical equipment.
2. Below 1.2 cal/cm2 you do not need full arc flash PPE to be worn. Your QEWs can be wearing everyday wear, but would not need full face protection or on the hands. They may still be exposed to shock and would require rubber insulating gloves with leather protectors.

Again the employer's Electrical Safety Program is the Management System used to state policy, practices and procedural requirements.


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