[Wayner]

I hope Frank doesn't mind this topic on his site, but it is an important topic. Frank, feel free to move it if you want.

Today I got home from work early again (yea!) and decided to do one of my job jar projects. I had a worn out outlet and it was time to replace it. The method is 1) de-energize, 2) verify, 3) make the change and 4) certify.

After finding the right breaker for the outlet in the panel, I shut it off. I used my nifty outlet tester to verify that power was off (and discovered I shut off the wrong breaker), then shut off the right breaker and started dis-assembly of the old worn out outlet. The spot was under my studio countertop and it was dark under there, so I had the Mrs. hold the flashlight while I did the swap-out.

A thought popped into my head and I asked the Mrs. "what would you do if I suddenly was getting electrocuted here doing this outlet change"? She stared at me with pondering eyes. Oh-oh. I asked "would you try to pull me away"? She said, "I'd go shut off the breaker". But I said "I already thought I shut off the breaker". Then she thought she would shut them off one at a time until she hit the right one. I said "I'll be dead by then"!

So, over to the electrical panel we went and I showed her the main breaker. I said "stand to the right of the box and turn off the main breaker with your left hand". She said "oh, that one".

I remember from a class I had how many people still get electrocuted every year, on the job and at home. It's still quite a few.

Just always remember this when you are working around electricity: It is the devil. The day you start getting careless is the day it's going to bite you and bite you bad. Use your head and take zero chances. Always work on stuff proven to be de-energized. The best bet is to have an electrician do the work.

Wayner 

[rockadanny]

Good one Wayner! As soon as I get home I'm doing the same with my wife. Better to show her now than trying to explain from the other room while I'm getting juiced! And though I planned on getting juiced tonight with my system, it's of a different sort. Thanks Wayner!

[nathanm]

Lock out\tag out!

[oneinthepipe]

Of course I am just joking, but my wife might confirm that my life insurance premiums were "current" before deciding whether or not to cut the current.  

That reminds me to take a look at the insurance.  I don't want to leave my wife and kids in a financial bind.

[TomW16]

Good advice Wayner.  I need to buy one of those "nifty outlet testers".  I always shut off the breaker before working on a circuit and I short the hot to ground just to be sure before working on the circuit.  It is quite a surprise when you short a "dead" line only to have it spit at you before the breaker trips.  I thanked my dad that evening for instilling that safety double-check process into me. 

Never get complacent with safety.

Cheers,
Tom

[Zheeeem]

I doubt that my spousal unit would do anything at all for 2 reasons:

1.  When I last briefed her on our finances she grinned and said, "So you're worth more to me dead than alive?"

2.  Because the current is AC, it is exceedingly unlikely that the contact would be maintained unless there was something physically forcing me to be in contact with the current.  Or it was the main line into the house.

[Wayner]

AC will grab you and you won't be able to let go. Your body freezes.

Wayner

[avahifi]

I make it a point to not work on units hot on the test bench unless I have another person in the room.

The emergency backup plan is a wood handle broomstick next to the test bench to be used to poke me away from the zapps.

Regards,

Frank Van Alstine

[richidoo]

Check the wires with a voltmeter before starting.

[rustneversleeps]

Observe all safety precaution, and following safety procedure. So we have been told at work. However, many times we don't have the luxury to work on live circuit with another person. The job has to be done.

At home, how many time that live circuit has to be fixed when no one else around, just you.

I was repairing a radar beacon at work, old stuff, component level repair, and I was alone. At the output section of the unit there were four power tubes that put out 5000 killing volts of RF. The safety cover for the tubes had been lost (it was a cannibalized unit with many parts missing, my job was to make it work).

I was paying close attention to that dangerous area at the time knowing what I was up against. Then I tried to connect my RG-59 to the test port, I was holding the cable steadily, and still inches away from the power tubes. All of sudden I saw a big ball of orange light jumping at my hand holding the cable. Next thing I knew, I was frantically trying to pull my hand away from the light, it seemed like eternity, but I am sure it was only seconds.

I pulled myself out, my finger was burned with great pain, and I could smell the burn, but I survived 5000 volts.

The current has to go through your heart to kill you, touching a live circuit with one hand, if the current doesn't go through your heart, you'd just get a nasty shock. Therefore that 500Vdc in a tube amp doesn't really scare me, because I don't think that low of a voltage will jump at you, remember, it's only 500Vdc.

Folks, I am not downplaying safety, be very careful, don't work on live circuit if you can help it, electricity can kill. I have been lucky.

[TomW16]

AC will grab you and you won't be able to let go. Your body freezes.

Wayner

I thought it was DC that won't let you go since it is constant and doesn't fluctuate like AC does.  I'm not willing to test this theory out though.   

Cheers,

Tom

[dB Cooper]

An excellent book on this subject is "Empires of Light" by Jill Jonnes (yes, with two n's). It chronicles the early history of commercial electricity and the prolonged "Current Wars" between the DC supporters (led by Edison) and the AC supporters (such as George Westinghouse). In fact, electrocution as a means of administering the death penalty came about largely as a result of Edison trying to spread fear about the safety of AC and paint it as the "killer current" so the public would associate it with death. Great book. Highly recommended for those into scientific or technology history.

[Wayner]

Tom,

The 60 cycles of 120 volt is so fast, it will behave just like DC. Once your "locked up", there you go.

I know someone who was a welder. One day he was working on an overhead conveyor. He was hanging on to it for awhile, and one of his co-workers thought it was strange he hadn't moved for quite a few minutes. When they went up to him and asked if he was OK, they instantly recognized things were not well, he was being electrocuted. Well, they removed the power and the very unfortunate thing is that the guy lived. His nerves were all burned internally. As far as I know he still remains heavily drugged after about 4 years.

Wayner

[rustneversleeps]

120Vac isn't really high enough to throw you across the room, so when you touch it, you'll feel the shock, if the current is high enough, it grabs you, and your initial natural reaction is to pull your hand back, please don't let anyone stand right next to you, your elbow may knock him down.

I was removing a partially defective but functional radio off the facility roof one time (the radio had been dropped by the previous guy, so the chassis was hot, but I didn't know about it), while I was coming down with the radio in my left hand, I was grabbing onto the railing with my right hand for support, and that completed the path.

I had to pull very hard to disconnect myself from the railing, I pulled so hard that I fell onto the ground after I was disconnected, then everyone turned around and said "what happened".

That time, if my heart wasn't strong enough, or if it got knocked out of rhythm by the electricity, I would have passed out, and that's when the second person would use the broom handle to pry my hand off the radio or the railing (the fall of the body may disconnect me from the railing, or may not) to save my life, only if he's watching, of course.

[Dan Kolton]

The current flow through your muscles is what causes them to contract and "lock on".