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 Post subject: Determine PPE for Switchbards
PostPosted: Tue Nov 03, 2009 1:03 pm 
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Location: New Jersey
Can a 480 volt 2000A switchboard with a 2000A main breaker section and a 2000A distribution section be evaluated for PPE separately.
There is a chance they can have different PPE requirements and if so is this allowed?


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PostPosted: Tue Nov 03, 2009 2:50 pm 
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James wrote:
Can a 480 volt 2000A switchboard with a 2000A main breaker section and a 2000A distribution section be evaluated for PPE separately.
There is a chance they can have different PPE requirements and if so is this allowed?


Sure, they usually will be different and should be labeled so, but you have not provided enough info to determine that


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PostPosted: Wed Nov 04, 2009 5:38 am 
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A panelboard with a main breaker is considered as one peice of equipment for arc flash and carries one label should a switchboard (Sq "D' QED type) be considered two separate pieces of equipment? Both have common bus a opening exists between the two for the bus to pass.


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PostPosted: Wed Nov 11, 2009 4:09 pm 
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I am not sure what gave you the impression that a panelboard can have one label only. Number of labels on equipment depends on the incident energy across it. For example you'd have one class of Hazard Risk Categoy (HRC) on the line side of main breaker while another HRC on the bus side. Your safety policy should dictate how many labels go on the equipment. You could either place one label representing the worst case rating or multiple labels (at appropriate locations) if you want the equipment to be more accessible.

Regards.


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PostPosted: Wed Nov 11, 2009 4:52 pm 
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amohammed wrote:
I am not sure what gave you the impression that a panelboard can have one label only. Number of labels on equipment depends on the incident energy across it. For example you'd have one class of Hazard Risk Categoy (HRC) on the line side of main breaker while another HRC on the bus side. Your safety policy should dictate how many labels go on the equipment. You could either place one label representing the worst case rating or multiple labels (at appropriate locations) if you want the equipment to be more accessible.

Regards.


IMHO, a panelboard without barriers or separate sections should be considered as 1 piece of equipment. Arc flash standards assume, for the most part, that the worker makes a mistake so we must assume they make the worst one in the box. How can you assume that a wrench on the ground bus will not end up contacting the line side of the main?


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PostPosted: Fri Nov 13, 2009 6:20 am 
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I agree with the IMHO also.

I'll add my IMHO, multi labels could lead to confusion. I would not want to be in court because of two many labels lead the worker to be confused and he selected the HRC0 instead of the HRC3 and was injured.

If your doing your own company's study your more likely to get by with multi-labeling per panel sections, with detailed worker training. But a paid firm would most likely go with one label for the highest IE to base PPE on for all sections. Liability issues for everyone exist.


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PostPosted: Fri Nov 13, 2009 3:45 pm 
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I am opinionated on this issue of labeling equipment based on the worst case result. It does warrant to label certain equipment which poses more hazard than others. But in general, if we just make every piece of equipment in the facility almost inaccessible by placing worst case labels you are pretty much shut out of your own facility; not to mention the decrease in mobility due to heavy PPE which might lead to more errors.

I am not down playing the role of safety here but why would anyone who is not qualified or trained to work on electrical equipment approach it in the first place? Being cognizant of the hazards and making good judgement calls based on the available information will serve better in mitigating arc flash incidents.


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PostPosted: Fri Nov 13, 2009 4:48 pm 
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I have been very vocal (or since I am posting it might be "postal") here with regard to the fact that I absolutely do not agree with many of the restrictions of the standards.....so I do understand your pain.....but feel that I cannot argue with the obvious. Even the best trained and skilled people make mistakes, and hence arc flash and contact issues. We have had a discussion about this very issue in the past here and I believe the consensus was the same. Given a single enclosure with no barriers, I just don't see how one can guarantee that a mistake will not involve the line side of the main, without some sort of extremely unusual circumstances, that I can't think of. I would also argue for the case that tight enclosures would lend themselves to the most common or worst case errors.

Why do you believe that this is not the case? I don't understand your logic about not wanting to consider the worst case result. If we could always consider the best case results, then we would never need the standards or PPE.


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PostPosted: Fri Nov 13, 2009 5:22 pm 
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amohammed wrote:
Being cognizant of the hazards and making good judgement calls based on the available information will serve better in mitigating arc flash incidents.


You’re right. I could write a book on this matter. I had the same opinion for a long time. But I came to a realization on the methods some plants hire maintenance workers. Many industrial plants have multi-trade workers of limited electrical knowledge. This helps the company reduce maintenance overhead. Thus the problem. I have seen some plants hire maintenance workers based on he/she rebuilt a car engine once and did some electrical work with his cousin once. Ok, he/she is hired. The worker is asked to see why motor A is not running. Boom the worker is ignited by stupidity. Several people are to blame including the worker. Therefore, the government (OSHA) has to step in. Protecting people and develop rules and standards to be sure everyone is compliant to work safely from the employer to the worker. We make bad decisions, human error and mistakes no matter who we are. But the odds are stacked against a worker with limited electrical knowledge this I agree very much with you.

IMO, it is those having the knowledge should protect those that do not. I agree with your original statement. But many employers look at the bottom line (cheap labor) and workers looking for a jobs makes for an explosive environment. I wonder now days when cost cutting is at its worse, electrical safety in the American work force may be a lower priority, more then ever. What makes matters worse is that other countries have no NFPA 70E or OSHA and the end product sells for less because they do not have to pay for skilled labor or adhere to any regulations other then who to payoff. Today, I see a lot of companies saying NFPA 70E is not an OSHA regulation. So we will keep going the way we are because all this electrical safety stuff adds no value to our product. You get the point.

Sorry for the standing on my soapbox.

IMO, the method you use if multi labels load/line side or panel verses sub-panels is user dependant, as I have not seen any specific regulations saying either way. Mostly you’ll find professionals knowledgeable in the area with their standards. Speaking for myself, if I did use the load/line or multi-labels per panel I would be certain all qualified workers received specific training in understanding the label, demonstrated safe work practices and signed a document relating that the worker understands the specific labeling technique and knows how to mitigate the hazard in such cases.


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PostPosted: Fri Nov 13, 2009 5:26 pm 
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acobb, I was typing my book at the same time. Great minds think alike. You said it more concise though.. :o


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PostPosted: Fri Nov 13, 2009 5:56 pm 
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The wonderful thing about an online forum is that it brings people together that could otherwise never share experiences, opinions, and help to us all. I firmly believe that if we do not occasionally disagree, then someone would be occasionally lying!

And you are right, unfortunately if you can spell electrical there is a plant out there that will hire you and put you in harms way and then try to claim that you said you were qualified!

Cudos to you Jim!

And thanks Cableguy.


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