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 Post subject: Possible Inconsistance with NFPA 70E 2015
PostPosted: Thu Jun 18, 2015 3:20 pm 
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I am concerned about several POSSIBLE important inconsistencies I have found in this new version of NFPA 70E 2015. I will start here with the first and in future posts I will explain the rest.

Electrically Safe Working Condition (ESWC).

There are two situations where it is required to place the equipment in an ESWC.

FIRST SITUATION:

When these tree conditions exists simultaneously:
1. Equipment energized
2. Equipment exposed
3. Person inside the limited approach boundary (LAB)

SECOND SITUATION:

When these three conditions exist simultaneously:
1. Equipment energized
2. Equipment NOT exposed
3. Employee INTERACTS with this equipment in such a way that increase likelihood of injury from an arc flash exists.

After requiring to put an equipment in an ESWC if any of these two situation exists, the standard add this exception:

EXCEPTION:

When a disconnect switch or breaker that has been properly installed and maintained, is opened to achieve and ESWC for connected equipment or closed to restore the connected equipment to service, the equipment supplying this disconnect switch or breaker shall not be required to be placed in an ESWC provided a risk analysis has determined that there is no unacceptable risk.

Comments:

I assume by the way these paragraphs are written, that this exception applies to the SECOND SITUATION. It has to apply to one of them, but I can't see how this exception would apply to the FIRST SITUATION. If I am correct, lets assume the following:

There is a circuit breaker in a power panel that feeds a disconnect switch (which has been installed and maintained properly) which feeds a control panel located downstream from the disconnect.

This disconnect switch is energized, enclosed, and, even it has been installed and maintained properly, it has been determined that if the employee INTERACTS with this switch (i.e. open) this action represents an increase likelihood of injury from an arc flash. Because of these three conditions exist (energized, enclosed, and likelihood of injury), before interacting with this disconnect it should be placed in an ESWC (SECOND SITUATION). I would like to clarify that this SECOND SITUATION is requiring the disconnect switch, not the upstream equipment feeding the switch to be placed in an ESWC.

Now the exception kicks in. Since this disconnect has been installed and maintained properly and the interaction (i.e. open) is to create an ESWC on its downstream control panel, the equipment supplying the disconnecting means (i.e. the panel where the circuit breaker is installed) shall not be required to be placed in an ESWC.

What? Is this confusing? Should the exception say the following?

When a disconnect switch or breaker that has been properly installed and maintained, is opened to achieve and ESWC for connected equipment or closed to restore the connected equipment to service, this disconnecting mean (not the equipment supplying this disconnect switch or breaker) shall not be required to be placed in an ESWC provided a risk analysis has determined that there is no unacceptable risk.

I am interpreting the standard incorrectly or there is a problem in the way it is written?

Thanks for reading this lengthy post and I will appreciate your input.


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Fri Jun 19, 2015 11:02 am 
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Historically, Article 100 (I think it was 108) had a very simple section that "triggered" Article 120 and 130. If you were doing LOTO, then Article 120 applied. If you were doing energized work, then Article 130 applied. However Article 100 still had references to requirements for shock and arc flash hazard protection which were inside 130.4 and 130.7. An EEWP was triggered ONLY if a shock hazard was involved and curiously enough, arc flash only came about because of a consequence of a shock hazard (crossing the limited approach boundary). Obviously shock and arc flash are two different hazards with two different causes but that was the state of the Code at that time.

Subsequently in I believe the 2009 edition (might have my versions mixed up), two things happened. First, the additional criteria referring to interacting with equipment which captured arc flash in non-shock hazard scenarios was added. Second, the clauses in Article 108 were incorporated into Article 130 so that today we have 120 for LOTO or de-energized work, and 130 for energized work. However the exception that you are referencing is just about impossible to read any way that you try and I even submitted a request to the 70E Committee to revise it (which was rejected) but I believe that it is stating either one of two things:

1. Attempting to preserve the original Code intent. That is that tasks involved in de-energizing and re-energizing equipment purely for the purposes of achieving an electrically safe work condition do not require an EEWP. Say for instance the goal is to lock out a motor MCC bucket. Doing so requires an EEWP since it is energized work without the exception so moving to the MCC main breaker, that also requires an EEWP, and so on and so forth. But since the work doesn't really fall into any of the 3 exceptions, it becomes impossible without an "escape clause".
2. Similar to the previous itdea except that in this case, the Code is providing a way to avoid EEWP's when doing what would be considred normal operations while operating disconnecting means.

The former is a bit more restrictive in that for instance opening and closing a disconnect to check its operation without any intent to do LOTO or simply opening or closing cutouts for switching equipment on and offline (such as using redundant buses in a large substation) would require an EEWP while the latter seems to make more sense as to intent.

Furhter, the existing way that it is triggering EEWP's based on crossing the limited approach boundary is kind of silly because we can run into scenarios where for instance we are doing work close to energized and exposed equipment but not passing the restricted approach boundary and thus no PPE is necessary. An example is when working on exposed 120 V PLC wiring where the panels frequently have open, exposed terminals but the restricted approach boundary is 0" and the limited approach boundary is 3'6". The LAB is for ptoection of unqualified personnel only. In my mind the trigger should be the RAB.

As to where the exception kicks in on the first case, consider overhead style substations with fuse cutouts and similar "open" equipment. While not switching, it would not be considered exposed because it is isolated (as in several feed off the ground). But once we stick a hot stick up there to operate it, now it becomes exposed. Granted that when hot sticks are insulated to 100 kV per FOOT, the shock hazard is all but nonexistent but the way that "exposed" is defined, it counts ehenever tools or body parts, regardless of whether they are insulated or not, get within a certain distance (the restricted or limited approach boundaries).


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Tue Jun 23, 2015 1:31 pm 
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Do you agree with me that the exception should have said that the disconnecting means (in my example, the disconnect switch) should not be required to be placed in an ESWC, instead of the equipment supplying this disconnect switch (in my example, the power panel with the circuit breaker feeding this disconnect switch)?


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Sun Jun 28, 2015 7:53 am 

Joined: Mon Jun 09, 2014 9:19 am
Posts: 43
No, it is not confusing and I will tell you why. When you operate a disconnect whether it be a circuit breaker or an actual disconnect switch for the purpose of LOTO, you are performing a Normal Operation of that equipment. The 2015 70E has put a clause that states when performing a Normal Operation of electrical equipment that has been installed correctly, maintained properly, the doors are closed and secured, and there is no evidence of impending failure, you can operate that switch with an extremely low risk of failure. By making that statement they have worked around the need to put that disconnecting means into an ESWC. Since you are not working on that disconnecting means and only Operating it, you can do it energized with a low risk.
I don't think you are interpreting it incorrectly, I just think you are reading too much into it. Remember if you are not working on the equipment and only operating it the risk assessment would be to check the equipment for the 5 bullet points under Normal Operation. If all 5 of those conditions are met, very low hazard and you can operate the equipment energized. If you are actually working on that disconnecting means, then you will need to put that disconnecting means into an ESWC, that is where the exception comes into play. The way I read the exception it states that pretty well.
Thanks!


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Mon Jun 29, 2015 11:17 am 
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RECS wrote:
Do you agree with me that the exception should have said that the disconnecting means (in my example, the disconnect switch) should not be required to be placed in an ESWC, instead of the equipment supplying this disconnect switch (in my example, the power panel with the circuit breaker feeding this disconnect switch)?


This would be the exact problem I think the clause is intended to deal with back when it was inserted. Otherwise using that exact same scenario then you'd have to place the upstream device in an ESWC as well by the same logic, which would then require the upstream 2 levels up to be in an ESWC, and so on and so forth out to shutting down and locking out generators by mechanical means, which is obviously utterly impractical unless you control the utility and even then, its totally impractical to interpret the EEWP clause this narrowly.

This is the first point I made...that this would apply very strictly only during LOTO scenarios. The more liberal interpretation extends it to any switching operations. And yes I hear the comment about "normal work" with three caveats. The first one is that the exception was inserted 2 Code cycles ago. Yes you can side step it now but that was two Code cycles ago.

The second caveat is that the "normal work" term is defined (somewhat vaguely) in the Code but then NEVER USED in any of the myriad of tasks given in the task list. Each of them uses the concept but then provides their own spin on the definition directly, making the term "normal work" an orphaned definition.

And the third and even more important caveat is that the task tables use the concept of "normal work" (however contorted the definitions might be) but it is NEVER used as an exception to the EEWP clause. The EEWP clause has its own list of exceptions but "normal work" is not one of them. Prior to the 2009 Code cycle we had a rule I think back around Article 108 or 110 (it was deleted) that essentially gave 2 options for work: electrically safe, or energized work. EEWP was never invoked under electrically safe work. Once this article was dropped and energized work, even for the purposes of LOTO, fell under Chapter 130, that's when the exception was inserted. The paragraph doesn't have any real interpretational information so my best guess is that it is inserted to provide the function of "normal work" by becoming a new exception to the EEWP requirement. However it is so poorly worded that I can't figure out how to parse it.


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Mon Jun 06, 2016 4:20 pm 
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LovetaCycle:

Thanks for responding to my post of long time ago. I have been busy but now I can dedicate more time to this forum. Here are my comments to your answer.

First, we have to understand that there are three levels of equipment that are mentioned in the exception.

First, and the most upstream element, is the equipment feeding the disconnect switch. Let's name it CB
Second, is the disconnect switch. Let's name it DS
Third is the equipment that we want to place in an ESWC. Let's name it EQ.

The issue I am discussing is this. You do NOT need an exception to put the equipment supplying the disconnect switch (i.e. CB)) in an ESWC.

I believe this statement is completely wrong and unnecessary. Not very easy to explain so please follow through with patience.

First inconsistency. The issue is the disconnect switch (DS) feeding the equipment (EQ) that we want to place in a ESWC, not the upstream equipment (CB) feeding the disconnect switch. This equipment is two levels upstream from the equipment (EQ) we want to place in an ESWC.

The flow of work will be as follows. We need to put a certain electrical equipment (EQ) in an ESWC in order to do work. This equipment (EQ) is fed by an upstream (separated from EQ) disconnect switch (DS). We need to open DS to de-energize EQ. The questions is, do we need to place DS in an ESWC before interacting (opening) this DS? The upstream equipment from the DS (i.e. CB) is not even in the picture. It is irrelevant at this moment.

Second Inconsistency:

To understand this second inconsistency, we have to understand first that there are two DIFFERENT concepts with a very similar name.

NORMAL OPERATING condition. Equipment needs to meet 5 requirements (i.e. properly maintained, properly installed, covers in place, doors closed, and no evidence of impending failure).

NORMAL OPERATION (normal interaction). Nod defined. But assumed as opening and closing CB's and switches, actuating pushbuttons, etc.)

If the DS is operating under NORMAL OPERATING conditions, then you are permitted a NORMAL OPERATION (normal interaction, opening the switch). See NFPA 70E-2015 Article 130.2(A)(3). Therefore, the EXCEPTION is useless.

If the DS is NOT operating under NORMAL OPERATING conditions (i.e. DS cover latch not well secured), then Article 130.2(A)(3) can't be applied and any interaction NORMAL OPERATION with this enclosed DS (opening) would require to place it first in an ESWC.

If you still want to operate this DS without putting it first in an ESWC, you would need an exception.

Again, we are talking about the DS NOT the CB upstream!

If you read the exception, you will see that to apply it you need to satisfy the following requirements:

DS properly installed
DS properly maintained
A risk assessment has been done and does not identify unacceptable risk to open the DS
The interaction (opening the DS) is for the purpose of putting the downstream equipment EQ under an ESWC

If all these conditions are satisfied, only then, the exceptions kick in and you would expect to read as follows:

The DS shall not be required to be placed in an ESWC.

But instead it reads:

The equipment supplying DS (i.e. CB) shall not be required to be placed in an ESWC. This is wrong.

I just cannot explained better than this. I hope I did a good job.

Another interesting fact is that SOMEONE will have to conclude that the DS with a faulty door latch still does not represent an unacceptable risk when you open it. Good luck finding a safety person that will take this responsibility.


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 Post subject: Re: Possible Inconsistance with NFPA 70E 2015
PostPosted: Tue Jun 07, 2016 11:57 am 
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I asked a couple Code cycles ago with a Committee member to explain it. No one could explain it. I got some hand waving that it was from a particular Committee member. I entered a public input on it to reduce it to the case that it simply states that there is an exception to the energized work permit clause when it comes to LOTO. It was rejected without comment. There are no notes in the Handbook explaining it either. Suffice to say that the exception is incredibly poorly worded and that I can't find any value in it. It seems to have something to do with LOTO but it is unparseable.


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