Changing breaker live

[zog]

I am surprised and curious about OSHA's involvement in certifying workers for EEW. How does OSHA do this?

I cannot find any reference to this on OSHA's website or in their regs yet - still looking.


Kent

It does not exist, there is no "certification" for this.In fact unless it can be justified (And in OSHA's eyes it hardley ever can be) the OSHA regulations specifically do not allow Energized Work. I think he is confusing some terms.

 

[kid_stevens]

Well hoot,

Turn the power off and kill the 20 stores during store startup before the customers come in. Ex Military type electrician and turn the What OFF well yep I have hot swapped many live parts. Calm hands and the units are not capable of conduction of current until you switch them on goes a long ways to not causing a problem.

The movie on page one was a huge mistake to begin with. The blast was caused by a bolted short, Neutral was tied to Phase B of a Wye system. A little brains and some proper Marking would have gone a long way towards prevent that Arc blast.

 

[Microwatt]

Hot Work

Hot Work

I've been told that a 40 cal/cm2 blast is about the threashold that the human body can survive even with proper PPE. Anyone else heard that?

 

[weressl]

Well hoot,

Turn the power off and kill the 20 stores during store startup before the customers come in. Ex Military type electrician and turn the What OFF well yep I have hot swapped many live parts. Calm hands and the units are not capable of conduction of current until you switch them on goes a long ways to not causing a problem.

The movie on page one was a huge mistake to begin with. The blast was caused by a bolted short, Neutral was tied to Phase B of a Wye system. A little brains and some proper Marking would have gone a long way towards prevent that Arc blast.

Instead of a brave new world, we are experiencing a weird new world.

There were specific and special instructional courses for electricians on how to work on live equipment. MCC's, switchboards, switchegar and panels were all designed and constructed to provide some work to be performed live.

There are many trained electricians who can safely perform - and indeed performed millions of work activities - on live equipment. It took only ONE scientist who had devoted her life to the cause to change the NFPA and an entire industry. Most of her cases involved hack electricians who shouldn't be performing electrical work live or dead, and a few good ones who made an unfortunate mistake. An good electrician is perfectly capable to determine if HE can perform a job safely, it was always left to them to call it and should have been left alone. With the extensive 'mandatory' arc-flash PPE, the likeliness of an incident had dramatically increased since the bulky equipment seriously impairs dexterity and itself becomes a 'self-fulfilling prophecy'. Not to mention that the current calculations had proven to be based on wrong science and the released energy in actual test had proven to be magnitudes less than the calculated values.

 

[kid_stevens]

Another one has anyone ever told a Telecomm supervisor that the phone systems had to be shut down because all power must be off. At 25,000 a minute fine for loss of phone service all AC, DC systems must stay running in a Telecomm site.

I have laid on 10,000 amp battery buss bars while hooking up new batteries, rectifiers and inverters. Never more than a tickle.

 

[don_resqcapt19]

Another one has anyone ever told a Telecomm supervisor that the phone systems had to be shut down because all power must be off. At 25,000 a minute fine for loss of phone service all AC, DC systems must stay running in a Telecomm site.

I have laid on 10,000 amp battery buss bars while hooking up new batteries, rectifiers and inverters. Never more than a tickle.

If there is only a single power system the there is no way that the system is reliable. A well design power system for critical loads will have redundancy and a means of isolation between the redundant sources so you can isolate and shut down a source to work on it.

 

[zog]

I've been told that a 40 cal/cm2 blast is about the threashold that the human body can survive even with proper PPE. Anyone else heard that?

Yes, that where the pressures from the blast become too high for survival even in a flash suit. There is some debate on this an further testing is being done as I type this by the IEEE 1584 commitee. But most arc flash software programs will print "Dangerous" on the labels if >40cal/cm2.

 

[EBFD6]

Instead of a brave new world, we are experiencing a weird new world.

There were specific and special instructional courses for electricians on how to work on live equipment. MCC's, switchboards, switchegar and panels were all designed and constructed to provide some work to be performed live.

There are many trained electricians who can safely perform - and indeed performed millions of work activities - on live equipment. It took only ONE scientist who had devoted her life to the cause to change the NFPA and an entire industry. Most of her cases involved hack electricians who shouldn't be performing electrical work live or dead, and a few good ones who made an unfortunate mistake. An good electrician is perfectly capable to determine if HE can perform a job safely, it was always left to them to call it and should have been left alone. With the extensive 'mandatory' arc-flash PPE, the likeliness of an incident had dramatically increased since the bulky equipment seriously impairs dexterity and itself becomes a 'self-fulfilling prophecy'. Not to mention that the current calculations had proven to be based on wrong science and the released energy in actual test had proven to be magnitudes less than the calculated values.

Well put, I agree completely!

My opinion is that part of being a qualified electrician is knowing how to work safely within your limitations and the limitations of the equipment you are working on. There are some jobs that should never be done hot and other tasks that are done hot everyday without incident. The only thing that I would categorize as an accident would be equipment failure/malfunction causing unexpected results and possible injury, this is beyond our control and a true accident. These accidents I would imagine are a very small percentage of all "accidents". Most incidents that fall into the "accident" category I wouldn't classify as an "accident" but as an incident caused by incompetence or inexperience. It's sad that the government (OSHA) needs to make a blanket rule to protect people who are too stupid to watch out for there own safety. I have not taken a 70E class nor do I know or care what it says. I watch out for my own safety and if I feel the task can not be done safely hot it gets shut down. On the other hand I do hot work on a regular basis, typically working in 120/208 panels, changing ballasts, troubleshooting control panels - all done in a safe manner, paying attention to what I'm doing, using the skills and experience I have gained to not kill myself. I do not encourage anyone else to work anything hot. Like I said at the beginning of this post, everyone needs to know and respect their personal limitations, that is the key to working safely, not some mindless set of rules most likely written by a group of people who have never worked in the field and don't have the first clue about being an electrician.

Just my opinion, and you know what they say " Opinion's are like......", well you know.:wink:

 

[don_resqcapt19]

Well put, I agree completely!

My opinion is that part of being a qualified electrician is knowing how to work safely within your limitations and the limitations of the equipment you are working on. ...

One of the problems is the fact that a number of these incidents resulted from a "trap" left by a previous worker. Tools and other conductive objects have been left in the equipment, bolts have been left loose or other things like that you as a "trained qualified electrician" have no knowledge of until it is too late.

 

[riggenbw]

That's not the BEST option. Like you said you should kill the main if possible but it's not always feasible. It can be done if you do it very carefully.

Quick question though. Is it a snap in or bolt in breaker?

I don't think I've ever seen a "snap-in" 400 amp 3 pole breaker

 

[realolman]

...good electrician is perfectly capable to determine if HE can perform a job safely, it was always left to them to call it and should have been left alone.

everyone needs to know and respect their personal limitations, that is the key to working safely, not some mindless set of rules most likely written by a group of people who have never worked in the field and don't have the first clue about being an electrician.

I agree with both of these posters, and I think the cracks about "being a man" and "not understanding" are completely uncalled for.

Because a person does not agree with something does not make him some sort of macho, uneducated, incompetent nut.... seems to me that is supposed to be a basic premise of this forum.

I know what I know, and I know what what I can do. I resent being told how I need to do something that I know perfectly well how to do.

How many times have panels, boxes, or whatever been worked on hot without incident, .....millions, billions?

IMO this NFPA 70 E business is NOT going to help the situation of the electrician in the long run, and I don't think it's doing it much good in the short run either.

 

[cschmid]

So I have read arguments on this issue several times but we are dealing with the classification of good electricians. So can someone give me the definition of a good electrician?? is there a difference between good, experienced and qualified?? I believe we need to verify the definitions here as the work describe leaves an opening for legal consequences..

 

[zog]

So I have read arguments on this issue several times but we are dealing with the classification of good electricians. So can someone give me the definition of a good electrician?? is there a difference between good, experienced and qualified?? I believe we need to verify the definitions here as the work describe leaves an opening for legal consequences..

I bet if you ask, every single electrician thinks he/she is qualified (Few are), and they will all say they are good. Everyone will think they know how to work live safely, always have always will, and as long as they keep thinking that there will be thousands severly injured and hundereds killed every year.

I guess you cant teach old dogs new tricks.

 

[quogueelectric]

I had 2 near electrocutions on my job last week both excelent mechanics 30+ yrs experience follow osha rules as best they can. One backhoe broke a streetlighting pipe pulled out of the handhole back into the pipe. Went to pull the wirenut back out of the pipe and a bare bad strip on the copper was in between the wirenutted wires. Kneeling on moist ground finger got caught in between the 277v conductors. Was like a snake on a barbeque grill. His partner tried to pull him off first time he got hit badly too. He got back on his feet and got a good running start and knocked him free saving his life.

 

[zog]

We just want to shift the risk to the lineman who aren't covered by OSHA.

Oh really? Why do you think that? Heck they have thier own section that is about 10 times longer than all the other electrical areas in ISHA combined.

So yes, the calculations are good, and someday about 20 years from now, maybe half to three-quarters of the equipment will be marked with arc flash hazards based on calculations.

About half are now, in industrial plants anyways, on the high energy systems the 70E is really targeting.

In the mean-time, I'm just advocating that all personnel who work with electricity understand the principles of arc-flash so they can make judgements on the safety of a procedure. We need to develop that same intuitive fear of arc-flash that we have of heights.

Now that may be the most level headed comment in this whole thread.

 

[zog]

Perhaps that is one of zog's point: the difference between perception and reality. I may have done things in the past I thought were safe but, through my own ignorance, was unaware of the danger level that may have been there.

Exactly!!!! I have done the same in the past, did some stuff that makes me shiver now that I know better, if you would have asked me back then I would have said I knew what I was doing and could do the work safely. After all i had before and nothing too bad ever happend.

 

[zog]

Ok here is the point

Ok here is the point

In a "perfect world" we would work on everything de-energized. We all know that is not possible. While the 70E "technically" applied to all electrical work, not all of it really does. The electric shock stuff applies to all, easy enough, wear glove, use insulated tools, etc...

What gets everyones panties in a bunch is the arc flash part. There are certian energy levels where an arc is not self sustaining. Lots of variables on this level, hard to determine, and the current guidelines (IEEE 1584) are suspect. What the 1584 says is that an arc flash study is not required for equipment <240V fed by a transformer <125 kVA. That eliminates a ton of stuff that most electricians work on. Note, is dosent come out and say there is not an arc flash hazard at this level, but rather you should use the tables. Looksat the tables and for most of the stuff most people work on it is HRC 0, that just means wear fabrics that dont melt and safety glasses. The stuff everyone has been required to wear by OSHA since 1981. Nothing new.

95% of the people complaining about the 70E requirements have no idea what they are.
95% of electricians dont work on the high energy equipment that will put you and everyone else in the room in a casket or burn center if you make one mistake.

Someday the 70E will change the scope to eliminate most of the stuff found in resi and light commercial, once the research has been done to know where to draw that line. There are some very smart people working on this, millions of volunteer hours, millions of donated dollars for the research and testing. Give them some time, they will make this all easier. Until then, tune up your spidey senses.

P.S. Those poeple that make stupid comments about the "people making the rules not having any experiiance", are the clueless ones. These people are trying to save lives, your lives, they are way smarter than you and are donating thier time.

 

[quogueelectric]

In a "perfect world" we would work on everything de-energized. We all know that is not possible. While the 70E "technically" applied to all electrical work, not all of it really does. The electric shock stuff applies to all, easy enough, wear glove, use insulated tools, etc...

What gets everyones panties in a bunch is the arc flash part. There are certian energy levels where an arc is not self sustaining. Lots of variables on this level, hard to determine, and the current guidelines (IEEE 1584) are suspect. What the 1584 says is that an arc flash study is not required for equipment <240V fed by a transformer <125 kVA. That eliminates a ton of stuff that most electricians work on. Note, is dosent come out and say there is not an arc flash hazard at this level, but rather you should use the tables. Looksat the tables and for most of the stuff most people work on it is HRC 0, that just means wear fabrics that dont melt and safety glasses. The stuff everyone has been required to wear by OSHA since 1981. Nothing new.

95% of the people complaining about the 70E requirements have no idea what they are.
95% of electricians dont work on the high energy equipment that will put you and everyone else in the room in a casket or burn center if you make one mistake.

Someday the 70E will change the scope to eliminate most of the stuff found in resi and light commercial, once the research has been done to know where to draw that line. There are some very smart people working on this, millions of volunteer hours, millions of donated dollars for the research and testing. Give them some time, they will make this all easier. Until then, tune up your spidey senses.

P.S. Those poeple that make stupid comments about the "people making the rules not having any experiiance", are the clueless ones. These people are trying to save lives, your lives, they are way smarter than you and are donating thier time.

This is probably the best post I have read since I joined.

 

[busman]

This is probably the best post I have read since I joined.

Wow. Me, Zog and the Cow all agree. I must still be sleeping.

Stay safe.

Mark

 

[realolman]

Zog, keep making the clueless, ignorant, old dog, smarter than you cracks.... that'll win you a lot of converts.