A Sobering Experience

[big john]

Early this morning I was doing some work on emergency power circuit, 120 1P, supplied lighting and exit signs and the like.

I chose to work the circuit hot, because all I had to do was make up one splice involving five conductors.

I'm holding these conductors with my left hand and trying to bunch them together with my Kleins in my right, being careful to keep my fingers away from the exposed copper.

Somehow, I slipped up.

I don't know what happened, but the next thing I know I'm being shocked. My left hand has seized up on the j-box and a couple of conductors and my right hand has a death grip on my Kleins. I'm being shocked and I can't let go.

Thank god I was working in a circuit over my head: My legs gave out and I fell away from the circuit, which probably saved my life.

I couldn't believe it. This was a 120 volt circuit, I didn't even think it was possible to get locked up on 120. I'd never heard of that happening to anyone. The only thing I can think to explain it is that my hands were sweaty, and this passed enough extra current to seal the deal.

It was a sobering reminder that even the low voltages can be dangerous as hell. If I'd been sitting down working in a floor box or somewhere where gravity wouldn't have been able to free me, I might've stayed locked onto that line until someone started to smell BBQ and wonder where I'd gone.

I could've ended up dead because I was too busy to go turn off a circuit breaker. Don't let that end up on your tomb-stone.

For gods sake, guys, be careful!

-John

 

[roger]

Re: A Sobering Experience

John, I worked for a company that had lost a service man a couple of years before I went to work for them, he was electrocuted on a 120 v

He had gone under a house some where around 8 to 9:00 am and they cut him loose around 8:00 pm

He was found laying on a black iron waste pipe with his hand in a jbox.

He was in his forties the way I understand it. (mighty young)

Myself, I have been hung up on 120 v and luckily like you, I was able to fall off of it.

On the other hand, I have been blown up in 480v, lost all the skin on the back of both hands, couldn't see for three days, spent 10 days going to whirl pool therapy, and my eye site has never been what it was before the event.

I was very lucky, and in a lot of electrical accidents, it is not as forgiving as it was to you and me.

I will second your last sentence.

Roger

 

[sjaniga]

Re: A Sobering Experience

John,
The problem is, as humans we tend to forget, or at least block things out of our minds.

Years ago two coworkers and I were installing a 400-amp feed from a 2500-amp switchgear, we had just piped it in and needed to suck a mouse through it when one of the younger guys decided it would be quicker to push a metal fish tape through the conduit.

Just as I walked in with the shop vac I saw him in the gear with the fish tape in his hands, I grabbed it from him and was telling him how dangerous this was and told him to get the vac set up, unfortunately for me I did not know that the tape was only in the conduit about 40 feet and 25 was straight up to the ceiling.

As soon as I pulled once on the tape the weight of it started it to descend out of the pipe with some awesome speed, all I could do was watch it go right into the buss bars in the back.

Next thing I know I am waking up at the burn center and spent 3 months recooping. The guy setting up the vacuum said it sounded like the fourth of july grand finale and that I was blown back about ten feet.

This all happened the day after I had just received my journeymans card, oh the other guy gave up being an electrician that week.

I still work on those gears, but I take a ton more precautions.

Scott

 

[drg]

Re: A Sobering Experience

Muscles can only work in 2 ways , involuntary and voluntary or put in a another way they can only expand and contract,
I have had it explained that a electrical current run through a muscle with cause a invoulantary muscle reaction ( such as squeezing or " contracting" ) and you will not have a voulantary control ("expanding") until the muscle recieves no more electrical current.
I am sure there is a more precise medical way of explaning this but it kind of sheds light on why you could not let go.

Johngladyourheresafenow

 

[racraft]

Re: A Sobering Experience

Firefighters are taught, when searching a room in the dark, to go forward with their hands extended palm up, rather than palm down. This way the back (top) of their fingers will contact a wire, rather than the palm side (bottom) of their fingers. This way, if the wire is hot, when their muscles contract their hand will close away from, rather than around, the wire.

 

[jro]

Re: A Sobering Experience

Big John,if anything a pair of leather gloves would have helped,IMO

 

[big john]

Re: A Sobering Experience

Originally posted by jro:
Big John,if anything a pair of leather gloves would have helped,IMO

I've thought about that, especially when doing work in hot panels where things can be pretty crowded and you have to keep track of your fingers and tools at all times. It's pretty easy to get insulated tools, that's something I keep meaing to do, but I can't find any insulated gloves that look like they wouldn't be really bulky and awkward.

Maybe just some well-fit moisture resistant leather gloves would do the trick, I don't know...

-John

 

[websparky]

Re: A Sobering Experience

Two things to remember;

Leather is nothing more than cow flesh that is dried. Very simular to human flesh for conducting electricity. Leather gloves are never mentioned in any electrical safety information as a protective item.

More people are shocked, injured and killed by 110V than any other voltage......... they all thought that it "was only 110".

I am glad to hear all of you have survived your accidents.

Please be safe. Safety is an action, it does not exist on it's own.

 

[iwire]

Re: A Sobering Experience

Originally posted by websparky:
More people are shocked, injured and killed by 110V than any other voltage......... they all thought that it "was only 110".

I will second that!

John I got hung up quite a few years ago in much the same way in an occupied office building on 277 volt lighting circuits.

Bob

 

[pfriday]

Re: A Sobering Experience

i was taught as a firefighter that it isn't the electrical potential (volts) that kill you, it's the current. of course, there is a somewhat inseparable relationship between the two.

anyway, i think it was something on the order of one amp that is capable of stopping your heart.

 

[ryan_618]

Re: A Sobering Experience

Originally posted by pfriday: i was taught as a firefighter that it isn't the electrical potential (volts) that kill you, it's the current. of course, there is a somewhat inseparable relationship between the two.

anyway, i think it was something on the order of one amp that is capable of stopping your heart.

I've heard that before, and I'm not saying it is untrue, but I wish for all the people that have heard that expression that they also knew Ohm's law. As you said, there is a definite relationship between voltage and amperage.

 

[rickcham]

Re: A Sobering Experience

Big John

If you want to wear gloves, Do your self a favor go to a supply house and purchase a set of low voltage, rated at 1000v volts. try several sizes to find one that fits well but will not impair the working of your fingers. they can be a little snug.
I carry two sizes low and high voltage and both are two different sizes for the reason of working in tight panels.

 

[roger]

Re: A Sobering Experience

This was a pretty interesting thread.

Roger

[ October 29, 2003, 10:22 AM: Message edited by: roger ]

 

[don_resqcapt19]

Re: A Sobering Experience

This type of accident is exactly why OSHA says that you cannot work on energized circuits above 50 volts.
Don

 

[pwhite]

Re: A Sobering Experience

pfriday,
an electrical current of 4-6ma can be enough to freeze the muscles across the heart and lungs. there is a posting in the archives that tell the various currents and body reactions. if i have time this week, i will try to find it.

 

[jro]

Re: A Sobering Experience

OK Big John and everyone out there, for the record, I am not saying a pair of leather gloves is the way to go, I'm saying, at least put on a pair of leather gloves, I would rather touch a live wire with cow hide around my hand, than to touch the live wire bare handed, and Don I agree with what you are saying, but shutting the power off or waiting for the Power Co. is somtimes not possible, and that is when you take precations, I'll give this Example: Say I need to replace 5 277v ballast at Walmart, open 24/7, do I turn off the lighting circuits to do this or do I get on my lift and get the job done, that is where as electricians we run into a problem. And again for safety sake the ideal thing to do is turn off the power, practical I'll leave that up to you. JMO

[ October 29, 2003, 04:25 PM: Message edited by: jro ]

 

[don_resqcapt19]

Re: A Sobering Experience

jro,
Yes, you turn off the lights. No job is worth your life. Changing ballasts hot is not permitted by OSHA even if you have all of the required PPE.
There are 2 or 3 very large electrical contractors that will not work anything hot and have refused to work for customers that insist on things being worked hot. There are also some very large customers that will not permit anyone to work on there systems hot. At the industrial site where I'm at now, you will get fired on the spot for working things hot. Troubleshooting is permitted, but only with the required PPE.
Don

 

[brian john]

Re: A Sobering Experience

Was told (not backup for this) that more people die from 120 VAC than any other voltage, which makes sense more folks are exposed too 120 VAC.

Big john: Please remember as you make your way through the trade that 480/277 VAC is not 208/120 and can respond to ground faults and phase to phase faults in a catastrophic way. Arcing ground faults associated with 480 distribution has injured and killed more electricians in the Washington Metro area that any other voltage class.

I see so many of these faults (after the fact) and the electricians had no idea how damaging the arcing could be.

 

[big john]

Re: A Sobering Experience

What's ironic about this whole thing is that I often comment on how little respect people [homeowners, joe-handyman, etc.] give 120, regardless of the danger. That accident made me a hypoctrite. My whole thought process was:
"I've done this before, I know enough to be careful." and then "Besides, even if I get shocked, it's only 120."

-John

 

[iwire]

Re: A Sobering Experience

Originally posted by don_resqcapt19:
Changing ballasts hot is not permitted by OSHA even if you have all of the required PPE.

Don some further info would be appreciated, as I understood it we can work hot with PPE.

It is easy to say

Yes, you turn off the lights. No job is worth your life.

Much harder to implement.