Arc Flash Suits for Disconnects?

Status
Not open for further replies.

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Might have been "what if's", but either way there's still a chance it could happen.
There is a chance that it could snow in Wisconsin in July, should we keep the snowplow drivers on standby like we do in January?

NFPA70E requires you to apply a risk analysis in deciding if PPE is required.
Remember there is a significant chance that PPE will not protect you. I seem to recall the odds of not being protected by PPE are greater than the odds of small LOTO disconnects failing in the first place.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
... NFPA70E requires you to apply a risk analysis in deciding if PPE is required. ...

There's the salient point right there. A proper ASSESSMENT of the risk might show that the "Hazard Risk Category" is level 0 for all we know. That means a cotton long sleeve shirt, pants and underwear, then safety goggles and gloves IF NECESSARY. I mean come on, lets not get ridiculous here guys, do you normally show up to work in shorts, a sleeveless t-shirt and flip-flops?

8118188-363403-female-electrician.jpg
(Note: Even she has the sense to wear the proper shoes)

NFPA 70E is not a law, it's a suggestion. OSHA however is the law, but simply states that an employer MUST HAVE A PLAN for safety of electrical workers, it must be executed and employees must be trained on it, as well as periodically updated. Then it says that NFPA70E is a good example of such a plan, but anyone can come up with their own if they so desire.

Within the NFPA 70E plan, there are suggested ways to determine the Hazard Risk Categories, of if you are lazy, you can use the tables that assign HRCs to specific tasks at various voltage / energy levels. That is where the rubber hits the road. Prior to 2012, the HRC tables said that if you DO NOT do a hazard risk assessment and use the tables instead, then simple tasks like flipping on CBs and disconnects WITH THE DOORS CLOSED, are HRC 0, but if you do the assessment and it is determined that the HRC is 1 or 2, then it is 1 or 2. That rarely happened by the way for anything 240V and below and even only occasionally for most 480V equipment, as long as the doors are closed. The flaw that created however was that it created a DISINCENTIVE to perform the risk assessments! So in 2012 they flipped it and said if you want to use the tables IN LIEU of a proper assessment, and you do not know what the HRC is in a piece of equipment, then the HRC defaults to level 4 even for simple tasks like flipping a breaker or disconnect.* That was supposed to be the inducement for employers to DO THE ASSESSMENT that they were supposed to do all along.

The stubborn ones however are still taking the lazy way out and inconveniencing their employers by making them suit up rather than just have the freakin' assessment performed.

* Unless the equipment is labeled as "Arc Resistant", in which case it is back to HRC 0.
 

kwired

Electron manager
Location
NE Nebraska
Wearing PPE isn't about operating things under normal conditions, it's about the abnormal conditions.

In all the years you've been doing this, how many breakers have you had blow up in your face? My guess would be the same number as me, none. But how many do you need to blow up in your face before wearing PPE is a good idea?

Where's Zog when we need him?
The electrical professional is easier to convince what could happen. How many non electrical professionals operate switches and never know there may be a potential for the thing to blow up in their face - especially if they never opened any dead front. It is kind of assumed that thing is inside an enclosure to protect you from what is inside. You do not need to be an electrical professional to LOTO an electrical source because you are doing mechanical work on some machine.

Were those videos documenting actual cases or just staging a "what if"?
All the videos I can ever recall seeing were always someone working on some gear with covers open as well. If we have 10kAic equipment but 30kA available fault current and a switch blows up, isn't the problem misapplication more so then the guy not wearing PPE - especially if he did not have a cover open when operating it? Wearing PPE will not keep it from blowing up.

Most people that know enough about electricity to be a hazard to themselves, typically only have worked on things at home, or friends or neighbors houses - where fault currents are typically low enough this kind of hazard is nearly non existent. Put them in a commercial or light industrial setting and the available fault current can easily be much more of a hazard - but they haven't got a clue. They may not be planning to dig into it too much but have no problem with attempting to reset a circuit breaker if they find one that is tripped.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
There is a chance that it could snow in Wisconsin in July, should we keep the snowplow drivers on standby like we do in January?

NFPA70E requires you to apply a risk analysis in deciding if PPE is required.
Remember there is a significant chance that PPE will not protect you. I seem to recall the odds of not being protected by PPE are greater than the odds of small LOTO disconnects failing in the first place.
Snowplow? What's a snowplow?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
They may not be planning to dig into it too much but have no problem with attempting to reset a circuit breaker if they find one that is tripped.
And closing a large circuit breaker that tripped on a very high fault current into that same existing fault can be real surprise! Circuit breakers are not required to withstand an unlimited number of maximum current faults.
 

kwired

Electron manager
Location
NE Nebraska
And closing a large circuit breaker that tripped on a very high fault current into that same existing fault can be real surprise! Circuit breakers are not required to withstand an unlimited number of maximum current faults.
Yes, I agree with that. But your non electrical professional - maybe a general maintenance man is the poor guy that doesn't know this and is the one who is not using any precautions when he goes to turn that back on.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
And closing a large circuit breaker that tripped on a very high fault current into that same existing fault can be real surprise! Circuit breakers are not required to withstand an unlimited number of maximum current faults.

Luckily, the possibility of a 3-phase bolted fault occurring is extremely low, unless there has been a wiring error. In general, we all need to rethink our 'tripped protective device' philosophy. Honestly, how many electricians reset a tripped device as the first step in their troubleshooting?

But the OP was about turning off something that had been on, not about resetting a tripped device.
 
Last edited:

iwire

Moderator
Staff member
Location
Massachusetts
Yes, I agree with that. But your non electrical professional - maybe a general maintenance man is the poor guy that doesn't know this and is the one who is not using any precautions when he goes to turn that back on.

OSHA rules prohibit the untrained from doing things.

Yes, I understand it is a real world out there and things happen. But the employer is legally bound to provide training to workers for the tasks they do. The problem is many employers, bosses etc have no clue training is required.
 

kwired

Electron manager
Location
NE Nebraska
OSHA rules prohibit the untrained from doing things.

Yes, I understand it is a real world out there and things happen. But the employer is legally bound to provide training to workers for the tasks they do. The problem is many employers, bosses etc have no clue training is required.


Exactly the point I have been after, electrical professionals will at least have some clue there may be a hazard, others can't be expected to know.

Kind of like all the commercial vehicle laws, many vehicles out there not in compliance and the owners have no clue they are doing anything wrong. Not as much of a problem with big rigs, you have to know a lot of this stuff to get a CDL license, but for smaller trucks that don't need a CDL to drive - there are many of the same rules for the vehicle itself and the only way owners find out is when they receive fines for non compliance:(
 

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
OSHA rules prohibit the untrained from doing things.

Yes, I understand it is a real world out there and things happen. But the employer is legally bound to provide training to workers for the tasks they do. The problem is many employers, bosses etc have no clue training is required.

Does OSHA ever allow hot work? Trained or not.
I'm no stranger to hot work but my son has been pressured to do ballast changes hot. He had very little experience.
 

kwired

Electron manager
Location
NE Nebraska
Does OSHA ever allow hot work? Trained or not.
I'm no stranger to hot work but my son has been pressured to do ballast changes hot. He had very little experience.
Taking voltage, current and other measurements is almost always going to require some exposure. Then you have the issue of terminating something onto something else when it is live - which is generally not allowed without a "hot work permit".

OSHA doesn't really set the rules though, they just require an electrical safety SOP. NFPA70e just so happens to be the easiest way to have a fairly thorough SOP, but a company can surely write up their own SOP. But it may very well be challenged if it is adequate enough should there ever be an accident under the self written SOP.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Does OSHA ever allow hot work? Trained or not.
I'm no stranger to hot work but my son has been pressured to do ballast changes hot. He had very little experience.
In general, other than for troubleshooting, live work is not permitted no matter what training or PPE you have.
 

iwire

Moderator
Staff member
Location
Massachusetts
Exactly the point I have been after, electrical professionals will at least have some clue there may be a hazard,

Hmm, there is no such thing as an 'electrical professional' or even 'electrician' to OSHA.

Even though I have electrical licenses issued by state governments, unless I have had specific, current training on my task I am not qualified to do it as far as OSHA is concerned.

As far as OSHA is concerned the custodian can be just as qualified to reset a breaker as an electrician could be. Both need training in that task. Some electricians have a very hard time accepting that concept. They figure an electrical license means they are automatically qualified to do any electrical task.


others can't be expected to know.

But they are expected to know, just like you are expected to know paying your taxes is required, or that the town 30 minutes away has local electrical amendment you need to follow when working there. :)


Kind of like all the commercial vehicle laws, many vehicles out there not in compliance and the owners have no clue they are doing anything wrong. Not as much of a problem with big rigs, you have to know a lot of this stuff to get a CDL license, but for smaller trucks that don't need a CDL to drive - there are many of the same rules for the vehicle itself and the only way owners find out is when they receive fines for non compliance

True, and when caught they will be fined. I suspect saying "I did not know' rarely gets you out of a ticket for commercial vehicle violation.


In my time in the trade I have only seen safety compliance increase, it's certainly not perfect yet but is getting better. Even large companies outside of the electrical trade are starting to learn that they and the contractors they hire have to have safety programs.

Its the Mom & Pop shops that don't know and I am not sure how that can be rectified.:happysad:
 

iwire

Moderator
Staff member
Location
Massachusetts
Taking voltage, current and other measurements is almost always going to require some exposure. .

To do those tasks OSHA requires PPE. (Personal Protective Equipment)

Then you have the issue of terminating something onto something else when it is live - which is generally not allowed without a "hot work permit"

Truthfully that is almost never allowed by OSHA as that is not troubleshooting.

The only way you might skate around it is by saying 'removal of power creates a larger hazard' but honestly when is that true?

Could you defend that position in court if something happened?


.

OSHA doesn't really set the rules though, they just require an electrical safety SOP.

I have to disagree, OSHA has a lot of direct rules that must be followed. On the other hand 70E seems to be more like you describe.


(kwired, by the way I am not trying to single you out, its just that you bring up a lot of good talking points. :) )
 

kwired

Electron manager
Location
NE Nebraska
Hmm, there is no such thing as an 'electrical professional' or even 'electrician' to OSHA.

Even though I have electrical licenses issued by state governments, unless I have had specific, current training on my task I am not qualified to do it as far as OSHA is concerned.
But there is no training requirements set by OSHA either, it is set by your company just like the safety SOP. Their may be third party guidelines that are used because it helps make the whole process easier and puts all the R&D on that third party.
 

zog

Senior Member
Location
Charlotte, NC
But there is no training requirements set by OSHA either, it is set by your company just like the safety SOP. Their may be third party guidelines that are used because it helps make the whole process easier and puts all the R&D on that third party.

1910.332 - In fact for electrical related violations this is the most common article cited and fined
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9909

This is about to be revised to mirror the NFPA 70E training requirements which are much more specific
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
1910.332 - In fact for electrical related violations this is the most common article cited and fined
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9909

This is about to be revised to mirror the NFPA 70E training requirements which are much more specific
And in .332, they reference 29 CFR 1910.399, which is where definitions reside. A change a lot of people have missed recently is that a "Qualified Worker" was defined somewhat loosely in the past;
Qualified person -- One familiar with the construction and operation of the equipment and the hazards involved.

now it reads;

Qualified person. One who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.

The janitor will be demanding a raise now...
 
Status
Not open for further replies.
Top