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Is this mitagating ?
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Author:  toolbbin [ Mon Apr 18, 2011 1:44 am ]
Post subject:  Is this mitagating ?
Can an operator in a plant open or close a 3phase 480v cb by using a fiberglass pole[ used by the electricians ] without ppe on and by being out of the 4' afb used in the task tables ? This is in mcc and we can.t afford electrical remote cb operators to do the work
Author:  haze10 [ Mon Apr 18, 2011 8:45 am ]
Post subject: 
If you are talking about LOTO on deadfront MCC buckets, PPE is not required as long as the equipment is in good working condition and you are not switching significant energy (switchgear). If you can operate it with the pole and be further away, you can do that also.
Author:  Zog [ Mon Apr 18, 2011 9:18 am ]
Post subject: 
haze10 wrote:
If you are talking about LOTO on deadfront MCC buckets, PPE is not required as long as the equipment is in good working condition and you are not switching significant energy (switchgear)


That is your opinion, 94% of the forum disagrees.
http://arcflashforum.com/showthread.php?t=1617
Author:  wbd [ Mon Apr 18, 2011 1:48 pm ]
Post subject: 
Is not switching on a MCC or any device "interacting" with the equipment? This would require PPE.

If you are outside the AFB, then you only need HRC #0 clothing (non-melting).
Author:  HWTIII [ Wed Apr 20, 2011 9:55 am ]
Post subject: 
Define "Interacting"

haze10 wrote:
If you are talking about LOTO on deadfront MCC buckets, PPE is not required as long as the equipment is in good working condition and you are not switching significant energy (switchgear). If you can operate it with the pole and be further away, you can do that also.


haze10,
I would really like to be able to agree with you. Is there a reference document to support the idea of "significant energy"? Prior to NFPA 70E-2009, I would basically agree with you. But recent clarifications (in 2009) required the consideration of the hazard when "interacting with the equipment in such a manner that could cause an electric arc." [FPN No. 1 on the definition of Arc Flash Hazard in Art. 100] The same note goes on to say "Under normal operating conditions, enclosed energized equipment that has been properly installed and maintained is not likely to pose an arc flash hazard." The "not likely" seems to be directly contrasted with the "possible release of energy" in the definition.

The NFPA 70E 2009 Handbook further suggests, "The technical committee suggests that the term interacting with the equipment could mean opening or closing a disconnecting mean, pushing a reset button, or latching the enclosure door. However, if the equipment [in good working condition], the chance of one of the actions initiating an arcing fault is remote."

So, the question seems to become "May I ignore the provided warnings when the chance of occurrence is remote?" The answer is, at the easiest, at the discretion of the qualified person(s) responsible for the interaction and, at the worst, the answer is completely unclear. :)

As to the original question in this thread, I would agree that if the worker is outside the boundary (by use of the fiberglass pole), the only electrical PPE is the OSHA requirement that natural fibers be worn (flammable, non-melting).

(Related Side note: when applying the NFPA 70E tables for LV locations, you have to be sure that you meet the applicable criteria for maximum available fault current and maximum clearing time for an arcing event.)

-Wally Tinsley
Eaton Corporation
Author:  haze10 [ Wed Apr 20, 2011 1:20 pm ]
Post subject: 
I base my arguement on the literal reading of the text.

First, the original 2004 code was titled "Work on or near energized electrical conductors" So we can conclude this as an intent, even though the 2009 title changed to 'Work involving electrical hazards'. The basis being it is working on or near exposed electrical conductors that is the hazard.

Some text from the 2009 code:

Start with the 130 introduction, "Deciding to work on or near exposed electricial condutors should be a last resort..." Note the word 'exposed'.

130.1(A) .."energized electrical condutors and circuits part to which an employee might be exposed..""" Note again the risk is to 'exposed'

130.1(B)3..."The energized work permit is inteded to ensure that the increased risk associated with exposure to an exposed energized electrical condutor..." Why is it then that we do NOT need a permit to operate electrical equipment with covers on - if the the risk is the same as with covers off?

130.7.C.9 FPN.1 ..."The collective experience of the task group is that in most cases closed doors do not provide enough protection to eliminate the need for PPE for instances where the state of the equiopment is known to readily change (e.g., doors open or closed, rack in or rack out)." NOte: the committee does NOT say in 'all' cases closed doors don't provide adequate protection, and the example they cite refers to switchgear. Why go to the trouble to list one specific risk that is considered to require PPE even with covers on -if- all operations reqardless of risk require PPE with covers on.

When you read the whole text, the intent is obvious, like the original title, to protect workers exposed to live parts (not covered parts), and to limit the times that PPE is required with covers on to those few instances of extreme risk, like operating switchger.

The FPN "Under normal operating conditions, enclosed energized equipment that has been properly installed and maintained is not likely to pose an arc flash hazard." also adds to my belief that the vast majority of equipment the average operator or tech interacts with, in a maintained plant, should not be likely to cause an arc flash hazard. This does not mean it has to be rated 'Arc Flash Resistant or Proof' as that would bring us back to those areas of extreme risk, like switchgear.

Do I really exist in the 6% minority? I work with a dozen electricians on a daily basis and none feel the risk is the same with covers on.
Author:  HWTIII [ Thu Apr 21, 2011 7:35 am ]
Post subject: 
Thanks!

I appreciate that answer and logic.

I agree that if that kind of explanation is put into a local safety policy, the responsible, qualified parties have good reason to operate as you describe. As you noted in your final comment, common sense and real world experience suggest a decreased risk with "doors closed".

For the one writing and enforcing the safety policy the list of references you provided and the associated logic would be very helpful.

As to the 6% minority, I think you might be. In this case, though, that may be the leading edge: those engaged enough to go beyond the mathematical calcs. and determine safe work procedures in the context of the calculations as opposed to blindly accepting that answer as the single answer for all parties and all levels of interaction.
Author:  jghrist [ Thu Apr 21, 2011 10:27 am ]
Post subject: 
haze10 wrote:
130.1(A) .."energized electrical condutors and circuits part to which an employee might be exposed..""" Note again the risk is to 'exposed'

130.1(B)3..."The energized work permit is inteded to ensure that the increased risk associated with exposure to an exposed energized electrical condutor..." Why is it then that we do NOT need a permit to operate electrical equipment with covers on - if the the risk is the same as with covers off?

These articles refer to the Limited Approach Boundary, implying that they are about shock hazard, not arc flash hazard.
Quote:
130.7.C.9 FPN.1 ..."The collective experience of the task group is that in most cases closed doors do not provide enough protection to eliminate the need for PPE for instances where the state of the equiopment is known to readily change (e.g., doors open or closed, rack in or rack out)." NOte: the committee does NOT say in 'all' cases closed doors don't provide adequate protection, and the example they cite refers to switchgear. Why go to the trouble to list one specific risk that is considered to require PPE even with covers on -if- all operations reqardless of risk require PPE with covers on.

You assume that "doors open or closed, rack in or rack out" is a single example about switchgear. It's not clear to me that the "doors open or closed" is not a separate example about equipment with doors.

You often refer to "switchgear" as involving switching significant energy. "Switchgear" is a general term for equipment to disconnect circuits and it could include anything from panelboards to metal clad switchgear.

To be a useful distinction, you have to define what you mean by "significant energy."

Having said that, I don't disagree with your position. It's just that I don't see that the justification is clear cut. NFPA 70E to me is not at all clear on the subject. I would tend to look to the Article 100 definition of Arc Flash Hazard FPN No. 2 that references Table 130.7(C)(9) for examples of arc flash hazards. I wouldn't consider a task listed as Category 0 to be an example of an arc flash hazard.
Author:  haze10 [ Fri Apr 22, 2011 5:55 am ]
Post subject: 
My point for all examples, and I only listed a few, is that through out the text the direction on what to do, what to wear, what to fear, etc, is always referenced to working on or near live parts (as the 2004 title implies).

'The collective experience of the task group is that in most cases closed doors do not provide enough protection to eleiminate the need for PPE for instances where the state of the equipment is known to readily change (e.g., doors open or closed, rack in or rack out). Note that this is only my interpretation that the reference is switchgear, as its the only common electrical equipment that is racked in and out. I further use the term 'significant energy' in my comments because I (perhaps wrongly) believe that the logic of the task group was to require PPE, even with covers on, for those instances where switching or racking elements of electrical gear bridge or switch high energy loads, like switchgear. But to be even more conservative, you can extrapolate down to soemthing less than switchgear, like MCC buckets or panelboards -but - since it is an extrapolation it is for the user to determine that point, i.e., a 2000A molded case CB as a main in a panel board would approach the similarity of switchgear. I do NOT however believe PPE has to be applied universally to all electric equipment down to the 120V 20A circuit breaker in a lighting panel.

Art 130 does not exist in OSHA, so there is no OSHA reference. What OSHA said is that they would not fine an owner for an Arc Flash incident if they were following an Arc Flash program based upon Art 130. So it becomes the responsibility of the owner, who is developing and documenting, the arc flash policy to fill in the blanks on the grey areas. If the policy writer wants to say that PPE is only required when operating (with covers on) switchgear, than I believe that meets the limit of the text. If he wants to extrapolate down and say any point which changes state on an 800A load, or a 400A load, or even a 20A load, that is the grey area to be filled in by the policy owner. God forbid there is ever an incident, but, if someone was hurt while switching a 100A CB with covers on and did not have PPE since it wasn't required by policy, at least OSHA will have difficulty in leveling a heavy fine because you did not have an Arc Flash Program. You did have a program, and you filled in the grey areas as best you could. It does conform to Art 130 as it follows it to the letter on work on or near live parts, but covers on it was not so clear.

There is a balance point that a complex has to find for itself. If you feel the need for HRC is required for all personnel who operate electrical equipment with covers on, and you can afford the expense, then by all means this is the least risk approach, and good for you. But in the real world we are struggling to compete, and while we want to assure a safe work environment, we also want to gain maximum efficiency in our safety programs for the minimal cost.

With all that said, I need to rightfully point out one point of conflict with my logic. Table 130.7C9 will often call for HRC 0 for tasks that I would consider 'No PPE required' like operating CBs with covers on. I justify this is my mind because hidden in the text is the fact that there are two disticnt and seperate approaches to be taken for the selection of PPE, one is following IEEE1584, and the other is following the TABLE Method. All my comments are in refernece to the IEEE 1584 method, as clearly anyone reading the text will see a HRC 0 requirement for operations with covers on under the TABLE method. Having worked in the electrical field for 30 years I have a hard time believing that the risk of injury is great for someone in street attire to switch a 20A lighting breaker.
Author:  A King [ Fri Apr 22, 2011 9:28 am ]
Post subject: 
I think there is the CYA legal interpretation and on the other extreme the absolute refusal to acknowledge the new definition of the AFPB. I believe there is most definitely a gray area left by 70E in between these two views and that we need to take a common sense approach by considering the probability and severity of potential injury and then writing our policy and training our workers accordingly.

We allow operators to open machine disconnects for LOTO after properly interrupting the load; these panels are HRC 0 and the entire AFPB is typically contained within the enclosure. If you are outside the AFPB there is no AF PPE required (130.3). We also do not require AF PPE to operate 20A circuit breakers to turn on the lights in the plant but we do make sure the panels/circuits are properly installed and maintained. However, I did say AF PPE would be required to operate the CAT 3 breaker with covers ON in the [url="http://arcflashforum.com/showthread.php?t=1617"]poll[/url].
Author:  Triton45 [ Fri Sep 16, 2011 10:42 am ]
Post subject: 
Is there enough information here?

You are giving answers to a question that as a craftsman and leader in the industry I would never answer with this little of information.
3-phase 480-volt circuit breaker
What type of enclosure?
Is it designed to be operated in this manner?
How is the operator going to verify that no voltage / energy is present after de-energizing?
Can't afford electrical remote?
Do you have qualified electrical personell working in the facility?
Do you have an Arc Flash Progam?
These are a few of the questions I would want answered before I giving any response.
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