A couple questions on arc flash protection requirements.
Is flash arc protection required when you follow the 120 section and
do a lock out and tag out on electrical equipment? (Just in case
there is a difference I am reading from the 2004 edition.)
From reading Article 110.5 it appears to me the reccomended route is
following Article 120 using L.O.T.O. which does not require arc flash
protection and if that is not feasible use Article 130 which gets in
to arc flash protection.
Also is there any on-line letter of interpetations? Such as the ones
on the OSHA web site?
Sounds like the NFPA is up to there old tricks of trying to sell more books
by renumbering them....But based on the 2000 NFPA 70E....
I think you hit the nail on the head. Lock out and tag out whenever
possible. Check to see if the equipment is energized and APPLY SAFETY
GROUNDS before working on the equipment. (The NESC has added a requirement
to apply safety grounds which is an excellect idea.) If NFPA70E is
mandatory, and if the equipment cannot be locked out then the available
fault energy has to be calculated and proper protective gear determined and
used according to the Tables, or the approach distance is 4 feet by NFPA
70E, and 12 inches by the NESC and OSHA for under 600 volt and over 50 volt
systems. Additonally, the energized equipment must be insulated from the
worker as much as possible using protective blankets, etc. and the worker
must use insulated gloves, hard hat, and sometimes sleeves before working
within the approach distance per OSHA and the NESC. There are so many
overlapping rules among OSHA, NFPA70E, and the NESC one almost has to be a
rocket scientist to determine what has to be done. I guess that is why we
need safety engineers to read and teach us about all these rules and to
lower the liabilities..
The key is using the terms "likely to require examination, adjustment,
servicing, or maintenance while energized " as used in the NEC. If NFPA70E
is mandatory, equipment such as motor control centers, panelboards, and
switchboards would have to have the fault energy calculated and the signs
applied telling workers what the approach distance is and which protective
equipment is required. Of course the interpretation of "likely to require
examination, adjustment, servicing, or maintenance while energized " is up
to the authority having jurisdiction. But this same term is used for
requiring work clearances in NEC Section 110.26 and work clearances are
always mandatory for panelboards, motor control centers, switchboards and
for any equipment that has overcurrent protection at 50 volts or more from
NEC Section 110.16 states Switchboards, panelboards, industrial control
panels, and motor control centers that are in other than dwelling
occupancies and are likely to require examination, adjustment, servicing, or
maintenance while energized shall be field marked to warn qualified persons
of potential electric arc flash hazards. However, this is a far cry from
NFPA70E that requires that the fault energy be calculated and that the
specified protective equipment and clothing be used..
Now for the real world:
I have found that adherence to the rules in NFPA70E at oil company
facilities such as the Alyeska Pipeline Marine terminal in Valdez, Alaska
will get the electrician foreman in hot water. What we actually do in the
field if enforcement is left to the electricians is keep our mouth shut and
work the equipment hot just like we have been doing in the past. NFPA70E is
not being adopted by most jurisdictions and probably will not be adopted as
long as the politicians listen to industry, because owners do not want to
pay the price for performing all those energy calculations and buying the
protective gear. I have heard several oil company safety engineers complain
that there is no exact science for calculating the available fault energy,
and that the several computer programs for this are not consistent in the
answers. It is sort of a wizard science to determine fault energy, for
I have some material online based on the 2002 NEC and 2000 NFPA70E. NFPA70E
cost me $85 to order and I thought that was outrageous since it is only 93
pages. However, I did study it and did some additional research last year.
This was right after I was laid off from my electrician foreman's job at the
Alyeska Marine terminal in 2001. Like a fool, just prior to lay off, I
requested proper protective gear for a couple of electricians that had to
install a bolt on 3-pole breaker in a 600 ampere 480 volt hot panel that was
near the transformer at a loading berth. I mentioned NFPA70E and boy did
that ever open up a bucket of worms with the Alyeska and contractor safety
personnel. You would think I was just trying to cause trouble from the
reactions I got. So much for NFPA 70E. As an electrician I now depend on
others to enforce such safety rules and I will continue to troubleshoot,
adjust, maintain and service hot equipment under 600 volts using standard
safety equipment and that is whatever is available at the time. I have been
hit about 6 times with 277 volts, probably 20 times with 120 volts and once
with about 20,000 volts from a traveling wave tube over the last 40 years.
Such is life. For the last year I have primarily worked on Class 2 low
energy circuits and I love it! No more shocks.
Slides 22, 23, 24, and 25. (this is based on the 2002 edition of the NEC and
the 2000 NFPA70E)
Arc flash protection is required when 'working' on 'exposed' 'energized'
equipment. Those three key words are the crux of the issue. If the
circuits are not exposed, no problem. If the circuits are deenergized, no
problem. If you're not actually 'working' on or within the prescribed
distance, no problem.
Now, 'deenergized' takes a little explaining.
Our company only considers a circuit panel 'deenergized' once the supply(s)
have been LOTO, *AND* the circuits tested dead with approved test equipment
(live-dead-live tests). And we consider performing this test as 'working'.
We *do* use arc-flash protection while performing this test.
We had an incident a few years back (1998?? before we adopted this policy)
when a worker was testing the 'stabs' in the back of a racked-out breaker to
verify they were dead and inadvertently went to the 'line' instead of the
'load'. And Murphy's law, one of the test lead/probes shorted one phase to
ground. The flash caused 1st and 2nd degree burns to the workman's face,
neck and hands. This was 'low voltage' by the OSHA definition, 480VAC MCC.
The *preferred* route is *always* to use LOTO and work only on *deenergized*
equipment. Working on *energized* equipment should be reserved only for the
most essential types of work. In our plant, only the plant manager can
approve working on energized equipment.
Hope this helps, stay safe.
Thanks, daestrom and Gerald on the replys. (BTW I'm an electrician)
The main reason I ask this is we have run in to a catch-22. We have
several pieces of equipment which requires above 100 calorie suits.
(Which from what I am told is not made.) So with a statement "must be
considered energized until proven", we can't work on this with out
violating the rules set up by the company. We have been getting "kind
of" answers when we ask what are we supposed to do. But no one has
stepped up and come up with a answer. Now we get some heat on why
can't you work on this? At present we have equipment which is down and
feed from a cubicle. Which we are told we cannot open to work on or
test. It is not feasible at present to shutdown the entire MCC to work
on it and if it was would that work still be "doable" since you still
have to confirm de-energized? I was hoping to find some kind of
definitive source either way. After working on the same equipment for
the last 15 years (32 years in trade) being able to lock equipment out
and work on it. It is discouraging not to be able to do my job.
What kind of MCC needs 100 c?? IIRC, the ones we have are 35 c for work up
through 4160V. Sorry, don't have it all memorized, we always consult the
procedure before starting.
Yeah, I hear you there. Even 208/120 is getting to be a pain. Been doing
it for almost as many years and *know* what I'm doing, yet the rules keep
But on the other hand, if you look at the OSHA stats on electrical injuries,
there has been an *increase* in the injuries to electrical workers (people
like us that 'know' what we're doing :-/. And many of those injuries are
happening on the lower voltage equipment (600V and under).
Personally, I argued that testing a circuit with an approved meter is not
*working* so should be allowed. But I was overruled. The burn case I
mentioned earlier was cited as *proof* that testing circuits is hazardous.
But what I neglected to mention earlier, is the guy was reaching deep into
the back of the cabinet to test the 'stabs' using a make-shift, foot-long
screwdriver on the end of his test leads. So the screwdriver shorted to the
frame while in contact with the hot stab/connector.
So now because this one dofus used jury-rigged test gear and got hurt,
instead of getting the right tool for the job, at our plant we always have
to suit up just to check it dead. (BTW, we *did* train everyone on the
proper test lead for the job and bought several spares.)
Actually some of the 480 volt MCC's according to the engineers calcs.
The trip response time on fault is too long. The higher voltages seem
to have a faster response time. On that note he originally did the
calculations on 20 year old data. But when he updated some of the fuse
size and ratings some actually went up. :(
I'm just waiting for the ballistic part to come. I.E. shockwave and
fragments. I'll get to wear one of those kewl bomb squad suits. I did
ask for one of the Oberon 100b suits
I know I'm running a up hill battle on this. For me its adds a risk
with the heat ( 90 to 100 degree ambient temps) and visability
restricted. I don't want to wear it unless really needed. We do have
the cool vests and they did get the airpump attachment for the hood.
Also they consider work when you are in 2 foot even doing thermal
scans and not touching anything. They even say since the topside of
the locked out breaker since it is still "hot" you have to have the
suit on. So replacing overloads or contactor require the full time in
One more bit of information. I called the OSHA people in Washington DC in
the Spring of 2004 to see if they were going to adopt NFPA70E. It was my
understanding from conversations with several experts that OSHA went to the
NFPA and asked them to write an electrical standard that could be adopted by
OSHA since the OSHA electrical safety rules were so outdated. NFPA 70E was
written to fulfill this request. OSHA told me they were looking at NFPA 70E
and probably would adopt only Part 1, General Requirements for Electrical
Installations which is a very abbreviated version of the NEC. Part 2 that
covers safe work practices was not going to be adopted without further input
from the industry. In my opinion, OSHA will not adopt a standard that is
going to place a severe financial burden on businesses as long as the
Republicans are in power.
What does it matter who is in charge? OSHA should be looking at the cost of
new regulations. Its all good and well to be safe, but being safely
unemployed is not ideal. There is a balance somewhere that has to be
reached. Claiming the republicans want to kill people to save a few bucks
is not only false (and you know it is false) but political hucksterism at
Well now, we are into politics. The facts as I see them are the Republicans
calculate the value of life verses the cost of saving a life and they have a
lower value of a laborer's life than the Democrats. For example, I would
suppose the Republicans would come up with about $300,000 as the value of a
life and the Democrats would come up with say about $1,000,000. I do know
Ted Kennedy fights very hard for stricter OSHA laws while the Republicans
fight very hard to curtail what they consider excessive safety rules that
might cost big businesses big bucks. In Alaska the Republicans control
State government. Since they took control the number of electrical
inspectors has gone from four to one and electrical inspections outside of
cities is a rarity. The State of Washington is controlled by the
Democrats. They have over 100 state inspectors and a full blown electrical
permit and inspection program. Additionally, while I was working in
Washington, I found that electrical contractors are much more aware of safe
work practices and attempt to comply.
Adopting NFPA 70E part 2 that requires energy calculations and appropriate
safety gear definitely places a higher expense on safety. The bottom line
is, did OSHA adopt this part? No, they haven't! And why not? And the
Republicans are in charge, now aren't they. I blame the Republicans. And
of course, they say, being safely unemployed is not ideal. So, I will take
my hits, Hey, getting shocked isn't so bad as long as you have a job, and
evidently that is what the Republicans favor - more electricians working
and getting shocked over fewer electricians working safely.
I'm sorry Bob but that just doesn't jibe with my experience. I have
worked for a fairly large number of electrical contractors in my thirty
five years in the craft and the ones that were always trying to cut
corners on safety were the smaller so called entrepreneurial outfits and
the owners had one thing in common. They were all right wing
republicans. To be fare the moderate republicans that I have worked for
have all understood that if you take care of the people they will take
care of the work.
Let me be clear that I'm not saying that all republicans will risk lives
to make money but that sizable and extremely vocal minority that are
always saying that you can quantify a human life in dollars and balance
that against the cost of the safety precautions are the ones I feel
totally justified in sniping at as people who would cut their own
mothers throat for five cents savings on a hundred installed feet of wire.
As my grandmother reflected "proof is in the puddin'". There seem to
be several groups that seem to migrate to the Republican ticket these
days. While they are in many ways different they are not necessarily
mutually exclusive. What seems to have jelled into the rather large
base (I suspect near 40%) these days seems to me to be folks that are
represented by a a combination of two or more of the first 6 types
listed. Some of my best friends argue for Republicans, I accept them
despite their faults and misdirections :)
In order of approximate numbers of Republican Voters.
1. Religious fundamentalists - mostly over cultural/social issues
2. Regular folks that are too busy, distracted, uninterested, or dumb
to check the facts
3. Pathologically 'logical' sceptical types that choose to first
believe the worst about everything
4. Extreme Liberterians - mostly over gun and state/federal powers
issues - I almost fit in here myself
5. Small business owners - fear of state/federal regulators or
sometimes simple greed
6. Racial and social bigots - many hide this well and are usually very
politically correct day to day
7. Big business executives - simple greed and short sightedness
8.The very wealthy - simple greed and short sightedness
9. Neo-Conservative elite - a machevien or fascist like belief in the
ignorance of the masses
"It's not what folks don't know that gets 'em in the most trouble,
it's the things they do know that ain't so" Will Rodgers
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