electrical deaths

I first remember it when I moved a lamp in the loft (attic) which my father had left there with the base off with live contacts exposed. It was unpleasant but not harmful. I only just manage to avoid putting my foot through the ceiling.

Later I was moving out of a flat (apartment) and we couldn't find the keys to turn the power off. The removal guys refused to disconnect the cooker (stove) live so I did it for them.

A few years ago (isn't everything nowadays?) I drew the short straw and had to compile a brief course on electrical safety. One of the statistics I remember was that there were about 30 electrical deaths per year in the UK, and by far most of these were people digging up cables or touching overhead wires with machinery. So in this case, not really connected with the domestic supply voltage.

It is probably all the safety standards in this country.

When I first started in a plant about 40 years ago there was very little safety precautions. In the last 20 or so years they got very strict following new govenment regulations.

The electrical code for homes has gotten onthe safety bandwagon. All the GFCI and arc flash circuits probably help.

Same here. Having dry skin helps a lot. There are still two real dangers though: wetness in whatever form and accidentally poking your finger into a socket where there's a live strand sticking out which punctures your skin. That's when you can *really* get a belt!

I once experienced an extreme example of the wet skin problem. I was standing chest deep in the Red Sea changing a pair of 9V batteries in a hydrophone preamplifier. When I touched one of the battery terminals I had a very unpleasant shock. John

On the other hand, you have USB chargers and other power supplies from China with poor to some having little barrier insulation. That being said, I have never hear about a fatality from that risk pool.

Actually, the regulations for building electronic devices are quite strict. At the same time, we have cars passing each other with a differential speed of 200km/h within a couple of feet. Kills a lot of people, but the regulations are never changed (hard to modify existing infrastructure)

Maybe you have more fires.

Only from 30,000 to 40,000 are killed in cars in the US evey year. That does not count many othe accidents. I was on the highway today and going 80 in a 65 mph speed limit . Getting passed by many cars as I was in the slow lane. That law dies not seem to be enforced very much.

And in general less efficiency since I2R losses are higher in the US ;-)

Most losses are in distribution, and that's kilovolts. Of course, the USA is BIG.

Serious appliances, like air conditioners and clothes dryers, run line-to-line, 240 volts. Modern TVs and LED lighting don't need much power.

Our wiring doesn't usually get warm.

We heat and cook with gas, and we don't have a/c or a pool or any silliness like that, so we don't use a lot of power.

But a tea kettle or a bread toaster or the microwave plug into 120, drawing quite some amps. If those connections get a bit rusty, they also get hot. And they need thick wires; thick copper is not that easy to wrap around connectors.

Electric tea kettles seem to be rare here.

It can also get nasty when muscle goes into spasm and contracts a hand or even just a finger round the conductor, so you can't get free easily.

My first unpleasant experience was with a 350V DC supply in a valve radio which I was trying to fix. I was holding the DC+ wire ready to resolder it to the smoothing capacitor. I had removed the capacitor from its mount, but it was still connected to the rectifier on the negative side. It wasn't in quite the right position for soldering, so I just went to pick it up to move it. I had completely forgotten that the case was connected to the -ve side, and got a hell of a belt from it. My hand contracted around the capacitor, and I wouldn't have been able to let go but my arm muscles also contracted and I involuntarily threw the capacitor 15 feet across the room. That broke the connection, but to this day I don't know why I hadn't turned off the power to the radio before resoldering. It could have been a lot worse.

Something I was taught, which has beceome an ingrained habit, is to touch anything for the first time with the back of your hand or fingers; if it is 'live' you will jump away.

Working in a radio factory brought home the need to apply that rule to everyday objects, as it wasn't unknown for some joker to wire up a door handle or a metal swivel chair to a high voltage supply. The other useful habit was to freeze if anyone threw anything towards you and shouted "Catch!" - the object that bounced off you was just as likely to be a charged high voltage electrolytic capacitor.

That is also fire training in a smoke filled space you walk forwards slowly when unable to see elbows out, forearms across and hands folded inwards. That way if you do touch a live wire hanging down the reflex thumps you in the chest but you don't end up permanently attached to it.

Waving your arms about there is a risk you will grab a live cable. People untrained tend to do this. The training setup only administers an annoying shock to remind people not to do it. Being in such dense though harmless smoke/fog is very disorienting.

One of my friends at university (at a top level institution) found himself holding a live plug a on Jesus lead left behind by a previous graduate student. The burns from that were horrific. Once attached you can't let go or move and burning human flesh doesn't smell good. He was probably only on for 30s before someone realised and disconnected him.

My only serious first aid at work was a US sparks being trained to install our 3 phase 240v instruments who checked for live the same way as he did in the US - lick fingers and touch. The resulting shock threw him up against a wall and knocked the life out of him for a while. He recovered after a cup of hot sweet tea and a couple of hours rest. Some impressive bruises resulted. Training was enhanced to prevent a recurrence. 240v is much more inclined to bite than 110v.

Telephone exchanges had such bars, powered with 48 volts and huge lead acid batteries connected to them. You could not unpower them, that would leave thousands of clients with no service.

A chap of our company was working around there, on a ladder. The "false floor" had one or two tiles removed for accessing the cables beneath. He fell, and he of course tried to grab something to stop the fall. A spanner was on his hand, and of course, it stuck between two copper bars.

It melted.

The entire island (Mallorca?) lost mobile phone service for an hour or two.

He was taken to hospital, unharmed but in shock. Maybe he had some small burning from the hot metal, I don't remember.

There was an investigation, but I never knew about the results.

...

What's a "Jesus lead"? I tried to google, but what I find are songs.

I forgot about room heaters. Here most of them are 2KW each, maybe switchable to 1KW.

Yep.

A mains cable with a plug at both ends. It means your home-made disco console can use a readily obtainable mains socket for power input and it doesn't matter which way round you unwind the cable. Another advantage is that you can unplug the console end and use it to fend off violent drunks.

I don't understand why they're not used more often.