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-   -   Youtube work safety vids (http://cellar.org/showthread.php?t=27524)

plthijinx 06-14-2012 05:54 PM

Youtube work safety vids
 
I was the lucky candidate chosen for our monthly engineering and safety meeting which takes place tomorrow morning.

At first i was going to do a presentation on "arc flashes" but realized that most of our engineers that do go to the field go for programming the systems that run the plant and don't get involved with big power voltages so i changed the topic to something more advantageous to our engineering dept.

that being said though, some of the research i did came up with a number of "educational work related" videos.

in the first video i'm posting below you will see a demonstration of "racking" a circuit breaker in what is called switchgear. (high voltage shit in layman's terms, this isn't your normal household voltage. I'm talking anywhere from 480 volts on up.)

now "racking" or "un-racking" a circuit breaker for this amount of voltage with a certain type of switchgear requires the use of a racking truck. see video below for a demonstration if you like because in the video that follows, if you don't understand what the guy was doing, it just doesn't make too much sense.


here in this video, the electrician is doing it properly. the gear is de-energized and he is wearing the proper "PPE" or Personal Protective Equipment" so that if something does go wrong he's protecting himself as best he can. in this video he is "un-racking" the breaker, in other words, removing it for whatever reason. be it maintenance, inspection and/or replacement.





now.

here's how not to do it. most likely (spoiler coming) this guy is not with the living any longer. both he and the helper failed to do several things. first and foremost they did not insure that the electrical equipment was de-energized prior to racking in the breaker. when the breaker made contact with the electrical bus it arced and exploded. secondly, what PPE is this guy wearing? hardly any.

in this case he should have been wearing a protective smock or suit along with properly rated gloves and helmet with face shield. if he had, he would have lived. or if he did live, his injuries would not have been nearly as bad.

fast forward to 1:10 and you'll see what an arc flash can do and why one needs to take every precaution available to prevent an accident.


zippyt 06-14-2012 06:00 PM

OOWWWWCCCHHH !!!

Undertoad 06-14-2012 06:06 PM

holy shit




PRETTY LIGHTS! though

zippyt 06-14-2012 06:08 PM

No safety vid thread would be complete with out this one ,

burns334 06-14-2012 06:13 PM

Quote:

Originally Posted by Undertoad (Post 815303)
holy shit




PRETTY LIGHTS! though

I second that

Beest 06-14-2012 06:14 PM

I've done my 2 day NFPA 70e including arc flash, 2 days of watching people get fried was good safety training, " I aint going nowhere near that shit"

Not strictly a safety video, but our safety guy showed it to us, funny one.


wolf 06-14-2012 06:59 PM

Zip beat me to extolling the wonders of the German Forklift Operator. I love that one. Saw it before there was a youtube. Such a classic.

glatt 06-14-2012 07:19 PM

Geez. I've got a screwdriver with a melted spot on it from a minor sparking accident in my own panel. I thought that was scary, but it was just a single pop and a couple little sparks. Nothing like this.

(Previous electrician had been sloppy removing insulation and there was a hot wire with a bit of exposed copper peeking out from a little gap in the insulation a good 6 inches from the end of the wire. Murphy's law says the screwdriver made contact with it while I was tightening a grounding wire in the panel.)

plthijinx 06-14-2012 07:45 PM

Quote:

Originally Posted by glatt (Post 815313)
Geez. I've got a screwdriver with a melted spot on it from a minor sparking accident in my own panel. I thought that was scary, but it was just a single pop and a couple little sparks. Nothing like this.

(Previous electrician had been sloppy removing insulation and there was a hot wire with a bit of exposed copper peeking out from a little gap in the insulation a good 6 inches from the end of the wire. Murphy's law says the screwdriver made contact with it while I was tightening a grounding wire in the panel.)

i've done that. more than once. not in a panel but trying to remove a staple that was holding the romex to a beam when we were remodeling the bathroom about a year ago.

the second time was when i trusted that my roommate turned off the correct breaker on a circuit i was splicing into. i checked with my voltmeter but didn't have a good connection and passed off the 12 or so volts as back feed from the neutral wire (very common in households with unbalanced circuit breaker panels). nope. it was hot. me and my Klein wire tool found out the hard way.

that was 120 volts though. nothing like the (i presume 4160v that the guy was working with above)

i've also been zapped with 208v. now that stings a bit. ok, A LOT. happened last year around this time at the panel shop i used to work for. then one of my cow workers got hit with the 480v side of a step down transformer (480v down to 120v). his arm turned all kinds of shades of red!

complacency is the bane of the existence of work related injuries. kinda why i started this thread. learn from others mistakes, and maybe even your own. talking about or reliving a mistake you made or a friend/cow worker at work or on an odd job around the house might make you think twice about safety and remember to be vigilant in whatever dangerous task is at hand.


let's reflect here. in the cases i mentioned above, i was hit with 120v and 208v. didn't kill me. know why? amperage. it's all about the amperage (with duration of electrocution thrown in as well)

from OSHA's website:


Three primary factors affect the severity of the shock a person receives when he or she is a part of an electrical circuit:
Amount of current flowing through the body (measured in amperes).
Path of the current through the body.
Length of time the body is in the circuit.

Other factors that may affect the severity of the shock are:

The voltage of the current.

The presence of moisture in the environment.

The phase of the heart cycle when the shock occurs.

The general health of the person prior to the shock.

Effects can range from a barely perceptible tingle to severe burns and immediate cardiac arrest. Although it is not known the exact injuries that result from any given amperage, the following demonstrates this general relationship for a 60-cycle, hand-to-foot shock of one second's duration:

Current level (Milliamperes) Probable Effect on Human Body:

1 mA Perception level. Slight tingling sensation. Still dangerous under certain conditions.

5mA Slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary reactions to shocks in this range may lead to injuries.

6mA - 16mA Painful shock, begin to lose muscular control. Commonly referred to as the freezing current or "let-go" range.

17mA - 99mA Extreme pain, respiratory arrest, severe muscular contractions. Individual cannot let go. Death is possible.

100mA - 2000mA Ventricular fibrillation (uneven, uncoordinated pumping of the heart.) Muscular contraction and nerve damage begins to occur. Death is likely.

> 2,000mA Cardiac arrest, internal organ damage, and severe burns. Death is probable.

Undertoad 06-14-2012 07:50 PM

OK so did you see the Indian guy who climbed on top of the train and reached up for the hot wire to steady himself...?

We're in Faces of Death territory here

glatt 06-14-2012 07:58 PM

When I was a kid, we had this fun game where we would touch a lally column at the bottom of the basement steps with one hand, and the armored cable near it with the other. The person who could hold on the longest would win. One day, I told my dad about it, and he seemed a little upset. :D He fixed it so the tingle went away and anybody could just stand there and hold both all day long.

plthijinx 06-14-2012 10:09 PM

Quote:

Originally Posted by glatt (Post 815320)
When I was a kid, we had this fun game where we would touch a lally column at the bottom of the basement steps with one hand, and the armored cable near it with the other. The person who could hold on the longest would win. One day, I told my dad about it, and he seemed a little upset. :D He fixed it so the tingle went away and anybody could just stand there and hold both all day long.

what is a lally?

wolf 06-14-2012 10:58 PM

My distrust of electricity is completely justified, isn't it?

xoxoxoBruce 06-14-2012 11:02 PM

Steel house column, usually in the basement.

plthijinx 06-14-2012 11:14 PM

Quote:

Originally Posted by wolf (Post 815363)
My distrust of electricity is completely justified, isn't it?

it is. however if you understand it, respect it, love it, caress it, i could go on.......

understand it and respect it and it will not bite you. get lackadaisical and it will hurt you.

thanks bruce, didn't know that


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