NFPA 70E and arc flash

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 my experience. 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 sure,

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.

Try:

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.

daestrom

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 its worst.

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.

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.

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 changing.

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.)

daestrom

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.

-- Tom H

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 the suit.

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

1. Neo-Conservative elite - a machevien or fascist like belief in the ignorance of the masses

Matt