Work on energized equipment without PPE

[don_resqcapt19]

Yes, if you do not pay attention it is. I know where my limits are. I can honestly say I have never even gotten close to being injured while working on live equipment. From voltages of 24 to 600 volts. I usually wear a good CLEAN pair of leather gloves and as long as they are dry, clean and do not have any matter such as oil, carbon, etc. I feel safe when working energized equipment.

In many of the recent arc-flash cases, the problem was caused by a previous worker...a tool left inside the equipment that fell across the bus when the next worker was taking off the cover...unkown things like that will get even the most careful worker.
Don

 

[busman]

Don,

In my example, I believe the lineman has a metal enclosure (the meter can). I see no difference in the two examples. I agree that pole work is different. Just one man's opinion.

Mark

 

[don_resqcapt19]

Mark,
Maybe the differnet OSHA rules do not apply to that type of work...not sure. I do know that some utilities require a disconnect on the line side of some meters so that their people can work on them without the power on.
Don

 

[natfuelbill]

I have always believed that was called hot sequencing or cold sequencing.

right?

 

[yanici]

Don't be fooled. Just opening a panel and a flash can occur. I got severe "welders flash" (like an internal sunburn to your eye) from shutting off a contaminated 480 volt breaker with the cover off. It flashed phase to phase at the breaker. It was only a 3 pole 30 amp, but the flash tripped all the way back to the 800 amp feeder breaker. I had melted copper in my eye glass lenses and burnt eye brows. If I'd been following NFPA 70-E it wouldn't have happened. Went blind for about 15 minutes. Thankfully my sight slowly retuned.

 

[busman]

All,

Please don't get me wrong. I am not advocating working hot. I've learned an AWFUL lot on this forum about the dangers of doing so. My only point was that the way residential work is done in most areas - SOMEONE has to work hot, be it electrician or lineman. There is NO safe disconnect provided or required. So, I have my arc-flash shield and coat and hot gloves and I use them, but someone has to take a risk somewhere.

Mark

 

[bkludecke]

I worry more about my electricians driving the trucks, working on ladders and using the wrong/damaged tool than I worry about them working hot. In energized work they respect the danger and think about safety. Driving from job to job they think they can eat, talk on the cell phone and look at a map at 50mph on a mountain road. If the energized work seems dangerous to me, I do it myself (OSHA/CAL-OSHA does not apply to me as the owner). I also have been doing it for years (but I also used to smoke cigs too).

 

[Natfuelbilll]

bkludecke brings up an interesting thought on this issue, although a review of

http://money.cnn.com/2003/10/13/pf/dangerousjobs/

might be worthwhile.

Who do electricians ultimately answer to, to work safe?
Who really holds them accountable?
Who, or what, makes them do what they do, or don't do?


An electrician/owner, apparently himself.
An electrician's supervisor, that would be OSHA.
An electrician, that has to be himself - self preservation.
An electrician's customer, would that be OSHA again?
An electrician's co-worker, maybe Union rules?
An electrician's spouse, maybe she is all to happy to get rid of him anyhow - or not.
An electrician's child?

It just may come down Ohm's Law....

 

[kingpb]

For what it's worth, Utility companies are not regulated by OSHA. I'm sure some here will feel the need to try and argue that point, but facts are facts.

The distinction that must be made is that not all companies providing power are considered a utility. They are IPP's (independent power producers) even though they provide the same power, or services as regulated utilities, they still must comply with OSHA. Subcontractors to the utility, would also have to comply with OSHA.

Not to say, that utility companies don't try to comply, it's just that they don't have to, and cannot be cited by OSHA for non-compliance.

 

[kingpb]

As far as compliance. I have seen a lot of discussion here related to OSHA, but it is NFPA 70E that provides the requirements for safe work practices. OSHA is the enforcing agent for safety.

The discussion has centered around changing breaakers in panelboards, so I will provide some info that will help many of you resolve their issue. Refer to NFPA 70E for complete text and information.

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Risk category 1 requires long pants that are either FR or made of 100% untreated natural fiber( i.e. cotton, wool, etc.) a FR long sleeve shirt, hard hat, and safety glasses, and leather work shoes (as needed). The gloves need to be leather, rated for the voltage class.

Those are pretty minimal requirements; and as professionals, electricians should be normally wearing anyway. So, for the residentail guys, it is pretty easy to comply.

 

[don_resqcapt19]

Please note that if you are working in the service panel, category 1 PPE may not be suitable because the line side power may exceed the requirements in Note 1. I wonder if any service panel can ever be category 1 as it is very unlikely that the utilty primary device will meet the 2 cycle maximum clearing time.
Don

 

[winnie]

While the utility primary devices are slow, usually the transformers are undersized and the feeders long. I bet that most residential panels are exposed to less than 10kA max short circuit current.

-Jon

 

[kingpb]

While the utility primary devices are slow, usually the transformers are undersized and the feeders long. I bet that most residential panels are exposed to less than 10kA max short circuit current.

-Jon

I agree, for there to be 10kA fault current at a 200A panel with a standard impedance for the transformer and cable, it would be hard to acheive. Also,
the arc flash is based on current and time, so as the current goes down the amount of time increases. You can work the formula backwards to see that even with a 7 cycles (0.116 sec) tripping time, it would be unlikely to have enough fault current to make it more then Category 1.

 

[jim dungar]

IEEE 1584-2002 is the primary tool used to perform Arc Flash Incident Energy calculations, but it does not address single phase circuits.

Note 1, of NFPA 70E says maximum of 25kA max AND 2 cycle clearing.

Most utility residential transformer protection clearing time is probably measured in minutes not in cycles.

And remember that the NFPA70E task tables 130.7(c)(9)(A) has been modified by TIA 04-01 which became effective on 5/5/04. You can find it in the back of the NFPA 70E book.